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  • 1.
    Correa, J.
    et al.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Bayer, M.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Göttlicher, P.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Lange, S.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Marras, A.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Niemann, M.
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Shevyakov, I
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Smoljanin, S
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Tennert, M
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Xia, Q
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Viti, M
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Wunderer, C
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Zimmer, M
    DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Graafsma, Heinz
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY, Notkestr 85, D-22607 Hamburg, Germany.
    Characterisation of a PERCIVAL monolithic active pixel prototype using synchrotron radiation2016Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, nr 2, artikkel-id C02090Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile And Large") is a monolithic active pixel sensor (MAPS) based on CMOS technology. Is being developed by DESY, RAL/STFC, Elettra, DLS, and PAL to address the various requirements of detectors at synchrotron radiation sources and Free Electron Lasers (FELs) in the soft X-ray regime. These requirements include high frame rates and FELs base-rate compatibility, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency (QE), and (multi-)megapixel arrangements with good spatial resolution. Small-scale back-side-illuminated (BSI) prototype systems are undergoing detailed testing with X-rays and optical photons, in preparation of submission of a larger sensor. A first BSI processed prototype was tested in 2014 and a preliminary result—first detection of 350eV photons with some pixel types of PERCIVAL—reported at this meeting a year ago. Subsequent more detailed analysis revealed a very low QE and pointed to contamination as a possible cause. In the past year, BSI-processed chips on two more wafers were tested and their response to soft X-ray evaluated. We report here the improved charge collection efficiency (CCE) of different PERCIVAL pixel types for 400eV soft X-rays together with Airy patterns, response to a flat field, and noise performance for such a newly BSI-processed prototype sensor.

  • 2.
    Correa, J.
    et al.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Marras, A.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Wunderer, C.B.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Göttlicher, P.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Lange, S.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY (Deutsches Elektronensynchrotron), Germany.
    Shevyakov, I.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Tennert, M.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Niemann, M.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Hirsemann, H.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Smoljanin, S.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Supra, J.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Xia, Q.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Zimmer, M.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Allahgholi, A.
    DESY (Deutsches Elektronensynchrotron), Germany; CFEL (Center for Free-Electron Laser Science), Germany.
    Gloskovskii, A.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Viefhaus, J.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Scholz, F.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Seltmann, J.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Klumpp, S.
    DESY (Deutsches Elektronensynchrotron), Germany.
    Cautero, G.
    Elettra Sincrotrone Trieste, Italy.
    Giuressi, D.
    Elettra Sincrotrone Trieste, Italy.
    Khromova, A.
    Elettra Sincrotrone Trieste, Italy; Università degli Studi di Trieste, Italy.
    Menk, R.
    Elettra Sincrotrone Trieste, Italy.
    Pinaroli, G.
    Elettra Sincrotrone Trieste, Italy; Università degli Studi di Udine, Italy.
    Stebel, L.
    Elettra Sincrotrone Trieste, Italy.
    Rinaldi, S.
    Elettra Sincrotrone Trieste, Italy.
    Zema, N.
    Istituto di Struttura della Materia, Italy.
    Catone, D.
    Istituto di Struttura della Materia, Italy.
    Pedersen, U.
    DLS (Diamond Light Source), U.K..
    Tartoni, N.
    DLS (Diamond Light Source), U.K..
    Guerrini, N.
    RAL (Rutherford Appleton Laboratory), U.K..
    Marsh, B.
    RAL (Rutherford Appleton Laboratory), U.K..
    Sedgwick, I.
    RAL (Rutherford Appleton Laboratory), U.K..
    Nicholls, T.
    RAL (Rutherford Appleton Laboratory), U.K..
    Turchetta, R.
    RAL (Rutherford Appleton Laboratory), U.K..
    Hyun, H.J.
    PAL (Pohang Accelerator Laboratory), Korea.
    Kim, K.S.
    PAL (Pohang Accelerator Laboratory), Korea.
    Rah, S.Y.
    PAL (Pohang Accelerator Laboratory), Korea.
    Hoenk, M.E.
    Jet Prop Laboratory, California Institute of Technology, U.S.A..
    Jewell, A.D.
    Jet Prop Laboratory, California Institute of Technology, U.S.A..
    Jones, T.J.
    Jet Prop Laboratory, California Institute of Technology, U.S.A..
    Nikzad, .
    Jet Prop Laboratory, California Institute of Technology, U.S.A..
    Graafsma, Heinz
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY (Deutsches Elektronensynchrotron), Germany.
    On the Charge Collection Efficiency of the PERCIVAL Detector2016Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, nr 12, artikkel-id C12032Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The PERCIVAL soft X-ray imager is being developed by DESY, RAL, Elettra, DLS, and PAL to address the challenges at high brilliance Light Sources such as new-generation Synchrotrons and Free Electron Lasers. Typical requirements for detector systems at these sources are high frame rates, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency, and (multi)-mega-pixel arrangements. PERCIVAL is a monolithic active pixel sensor, based on CMOS technology. It is designed for the soft X-ray regime and, therefore, it is post-processed in order to achieve high quantum efficiency in its primary energy range (250 eV to 1 keV) . This work will report on the latest experimental results on charge collection efficiency obtained for multiple back-side-illuminated test sensors during two campaigns, at the P04 beam-line at PETRA III, and the CiPo beam-line at Elettra, spanning most of the primary energy range as well as testing the performance for photon-energies below 250 eV . In addition, XPS surface analysis was used to cross-check the obtained results.

  • 3.
    Fröjdh, Christer
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Krapohl, David
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Fröjdh, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Thungström, Göran
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Spectral resolution in pixel detectors with single photon processing2013Inngår i: Proceedings of SPIE - The International Society for Optical Engineering, SPIE - International Society for Optical Engineering, 2013, s. Art. no. 88520O-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Pixel detectors based on photon counting or single photon processing readout are becoming popular for spectral X-ray imaging. The detector is based on deep submicron electronics with functions to determine the energy of each individual photon in every pixel. The system is virtually noiseless when it comes to the number of the detected photons. However noise and variations in system parameters affect the determination of the photon energy. Several factors affect the energy resolution in the system. In the readout electronics the most important factors are the threshold dispersion, the gain variation and the electronic noise. In the sensor contributions come from charge sharing, variations in the charge collection efficiency, leakage current and the statistical nature of the charge generation, as described by the Fano factor. The MEDIPIX technology offers a powerful tool for investigating these effects since energy spectra can be captured in each pixel. In addition the TIMEPIX chip, when operated in Time over Threshold mode, offers an opportunity to analyze individual photon interactions, thus addressing charge sharing and fluorescence. Effects of charge sharing and the properties of charge summing can be investigated using MEDIPIX3RX. Experiments are performed using both Si and CdTe detectors. In this paper we discuss the various contributions to the spectral noise and how they affect detector response. The statements are supported with experimental data from MEDIPIX-type detectors.

  • 4.
    Khromova, A.
    et al.
    Elettra Sincrotrone Trieste, S.S. 14 km 163.5, 34149 Basovizza, Trieste, Italy; Università degli Studi di Trieste, Piazzale Europa, 1, 34128 Trieste, Italy .
    Cautero, G.
    Elettra Sincrotrone Trieste, S.S. 14 km 163.5, 34149 Basovizza, Trieste, Italy.
    Giuressi, D.
    Elettra Sincrotrone Trieste, S.S. 14 km 163.5, 34149 Basovizza, Trieste, Italy.
    Menk, R.
    Elettra Sincrotrone Trieste, S.S. 14 km 163.5, 34149 Basovizza, Trieste, Italy.
    Pinaroli, G.
    Elettra Sincrotrone Trieste, S.S. 14 km 163.5, 34149 Basovizza, Trieste, Italy.
    Stebel, L.
    Elettra Sincrotrone Trieste, S.S. 14 km 163.5, 34149 Basovizza, Trieste, Italy.
    Correa, J.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Marras, A.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Wunderer, C.B.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Lange, S.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Tennert, M.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Niemann, M.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Hirsemann, H.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Smoljanin, S.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Luruper Ch. 149, 22607 Hamburg, Germany.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Graafsma, Heinz
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Göttlicher, P.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Shevyakov, I.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Supra, J.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Xia, Q.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Zimmer, M.
    DESY (Deutsches Elektronensynchrotron), Notkestr. 85, 22607 Hamburg, Germany.
    Guerrini, N.
    RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K..
    Marsh, B.
    RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K..
    Sedgwick, I.
    RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K..
    Nicholls, .
    RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K..
    Turchetta, R.
    RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K..
    Pedersen, U.
    Elettra Sincrotrone Trieste,Trieste, Italy; Università degli Studi di Trieste, Trieste, Italy; Università degli Studi di Udine, Udine, Italy; DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Hamburg, Germany; DLS (Diamond Light Source), Didcot OX 11 ODE, U.K.; RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K.; PAL (Pohang Accelerator Laboratory), Jigokro-127-beongil, 790 834 Pohang, Korea; j CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 U.S.A. .
    Tartoni, N.
    Elettra Sincrotrone Trieste,Trieste, Italy; Università degli Studi di Trieste, Trieste, Italy; Università degli Studi di Udine, Udine, Italy; DESY (Deutsches Elektronensynchrotron), Hamburg, Germany; CFEL (Center for Free-Electron Laser Science), Hamburg, Germany; DLS (Diamond Light Source), Didcot OX 11 ODE, U.K.; RAL (Rutherford Appleton Laboratory)/STFC, Didcot OX 11 OQX, U.K.; PAL (Pohang Accelerator Laboratory), Jigokro-127-beongil, 790 834 Pohang, Korea; j CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 U.S.A. .
    Hyun, H.J.
    PAL (Pohang Accelerator Laboratory), Jigokro-127-beongil, 790 834 Pohang, Korea.
    Kim, K.S.
    PAL (Pohang Accelerator Laboratory), Jigokro-127-beongil, 790 834 Pohang, Korea.
    Rah, S.Y.
    PAL (Pohang Accelerator Laboratory), Jigokro-127-beongil, 790 834 Pohang, Korea.
    Hoenk, M.E.
    CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 U.S.A..
    Jewell, A.D.
    CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 U.S.A..
    Jones, T.J.
    CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 U.S.A..
    Nikzad, J.
    CALTECH, NASA Jet Prop Lab, Pasadena, CA 91125 U.S.A..
    Report on recent results of the PERCIVAL soft X-ray imager2016Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 11, nr November, artikkel-id C11020Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The PERCIVAL (Pixelated Energy Resolving CMOS Imager, Versatile And Large) soft X-ray 2D imaging detector is based on stitched, wafer-scale sensors possessing a thick epi-layer, which together with back-thinning and back-side illumination yields elevated quantum efficiency in the photon energy range of 125–1000 eV. Main application fields of PERCIVAL are foreseen in photon science with FELs and synchrotron radiation. This requires high dynamic range up to 105 ph @ 250 eV paired with single photon sensitivity with high confidence at moderate frame rates in the range of 10–120 Hz. These figures imply the availability of dynamic gain switching on a pixel-by-pixel basis and a highly parallel, low noise analog and digital readout, which has been realized in the PERCIVAL sensor layout. Different aspects of the detector performance have been assessed using prototype sensors with different pixel and ADC types. This work will report on the recent test results performed on the newest chip prototypes with the improved pixel and ADC architecture. For the target frame rates in the 10–120 Hz range an average noise floor of 14e− has been determined, indicating the ability of detecting single photons with energies above 250 eV. Owing to the successfully implemented adaptive 3-stage multiple-gain switching, the integrated charge level exceeds 4 centerdot 106 e− or 57000 X-ray photons at 250 eV per frame at 120 Hz. For all gains the noise level remains below the Poisson limit also in high-flux conditions. Additionally, a short overview over the updates on an oncoming 2 Mpixel (P2M) detector system (expected at the end of 2016) will be reported.

  • 5.
    Marras, A.
    et al.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Wunderer, C.B.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Bayer, M.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Correa, J.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Goettlicher, P.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Lange, S.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Shevyakov, I.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Smoljanin, S.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Viti, M.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Xia, Q.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Zimmer, M.
    Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Das, D.
    Science & Technology Faculties (STFC), Didcot, U.K.
    Guerrini, N.
    Science & Technology Faculties (STFC), Didcot, U.K.
    Marsh, B.
    Science & Technology Faculties (STFC), Didcot, U.K.
    Sedgwick, I.
    Science & Technology Faculties (STFC), Didcot, U.K.
    Turchetta, R.
    Science & Technology Faculties (STFC), Didcot, U.K.
    Cautero, G.
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Giuressi, D.
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Khromova, A.
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Menk, R.
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Stebel, L.
    ELETTRA Sincrotrone Trieste, Trieste, Italy.
    Fan, R.
    Diamond Light Source (DLS), Didcot, U.K.
    Marchal, J.
    Diamond Light Source (DLS), Didcot, U.K.
    Pedersen, U.
    Diamond Light Source (DLS), Didcot, U.K.
    Rees, N.
    Diamond Light Source (DLS), Didcot, U.K.
    Steadman, P.
    Sussmuth, M.
    Tartoni, N.
    Diamond Light Source (DLS), Didcot, U.K.
    Yousef, H.
    Diamond Light Source (DLS), Didcot, U.K.
    Hyun, H.
    Pohang Accelerator Lab (PAL), Pohang, South Korea.
    Kim, K.
    Pohang Accelerator Lab (PAL), Pohang, South Korea.
    Rah, S.
    Pohang Accelerator Lab (PAL), Pohang, South Korea.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. Deutsches Elektronen-Synchrotron (DESY).
    Graafsma, Heinz
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Experimental characterization of the PERCIVAL soft X-ray detector2016Inngår i: 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2015, Institute of Electrical and Electronics Engineers (IEEE), 2016, artikkel-id 7581940Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Considerable interest has been manifested for the use of high-brilliance X-ray synchrotron sources and X-ray Free-Electron Lasers for the investigation of samples.

  • 6.
    Niskanen, Ilpo
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion. University of Oulu, Oulu, Finland.
    Forsberg, Viviane
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap. KTH.
    Zakrisson, Daniel
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion.
    Hummelgård, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Andres, Britta
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
    Fedorov, Igor
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion.
    Suopajärvi, Terhi
    University of Oulu, Oulu, Finland.
    Liimatainen, Henrikki
    University of Oulu, Oulu, Finland.
    Thungström, Göran
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion.
    Determination of nanoparticle size using Rayleigh approximation and Mie theory2019Inngår i: Chemical Engineering Science, ISSN 0009-2509, E-ISSN 1873-4405, Vol. 201, nr 29, s. 222-229Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Accurate determination of the size of nanoparticles has an important role in many different scientific and industrial purposes, such as in material, medical and environment sciences, colloidal chemistry and astrophysics. We describe an effective optical method to determine the size of nanoparticles by analysis of transmission and scattering of visible spectral range data from a designed UV-Vis multi-spectrophotometer. The size of the nanoparticles was calculated from the extinction cross section of the particles using Rayleigh approximation and Mie theory. We validated the method using polystyrene nanospheres, cellulose nanofibrils, and cellulose nanocrystals. A good agreement was achieved through graphical analysis between measured extinction cross section values and theoretical Rayleigh approximation and Mie theory predictions for the sizes of polystyrene nanospheres at wavelength range 450 - 750 nm. Provided that Rayleigh approximation's forward scattering (FS)/back scattering (BS) ratio was smaller than 1.3 and Mie theory's FS/BS ratio was smaller than 1.8. A good fit for the hydrodynamic diameter of nanocellulose was achieved using the Mie theory and Rayleigh approximation. However, due to the high aspect ratio of nanocellulose, the obtained results do not directly reflect the actual cross-sectional diameters of the nanocellulose. Overall, the method is a fast, relatively easy, and simple technique to determine the size of a particle by a spectrophotometer. Consequently, the method can be utilized for example in production and quality control purposes as well as for research and development applications.

  • 7.
    Norlin, Börje
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. FS-DS, Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.
    Fröjdh, Christer
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    X-ray fluorescence measurements of toxic metal content in ash from municipal solid waste incineration2017Inngår i: 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), IEEE, 2017, Vol. 2017-January, artikkel-id 8069695Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The vision of this paper is development of an online X-ray fluorescence method for monitoring of metal content in ash from municipal solid waste (MSW) incineration. With such measurements directly on site it is possible to optimize an ash washing process in incineration plants, allowing the fly ash to be stored in a landfill for non-hazardous waste. The presented X-ray fluorescence measurement assures that the measurement accuracy is sufficient for metal content monitoring. The actual measurement process is also fast enough to be possible to implement as an online measurement method. The optimal measurement setup is different for different metals. Several different metals might need environmental monitoring, which metals might vary over time due to systematic variations in waist content. Detection of a wide range of metals will require an X-ray source with variable voltage and multiple detectors.

  • 8.
    Norlin, Börje
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Fröjdh, Christer
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Nordin, T.
    Process Technology Department, MoRe Research, Örnsköldsvik.
    Precision scan-imaging for paperboard quality inspection utilizing X-ray fluorescence2018Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 13, nr 1, artikkel-id C01021Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Paperboard is typically made up of a core of cellulose fibers [C6H10O5] and a coating layer of [CaCO3]. The uniformity of these layers is a critical parameter for the printing quality. Current quality control methods include chemistry based visual inspection methods as well as X-ray based methods to measure the coating thickness. In this work we combine the X-ray fluorescence signals from the Ca atoms (3.7 keV) in the coating and from a Cu target (8.0 keV) placed behind the paper to simultaneously measure both the coating and the fibers. Cu was selected as the target material since its fluorescence signal is well separated from the Ca signal while its fluorescence's still are absorbed sufficiently in the paper. A laboratory scale setup is built using stepper motors, a silicon drift detector based spectrometer and a collimated X-ray beam. The spectroscopic image is retrieved by scanning the paperboard surface and registering the fluorescence signals from Ca and Cu. The exposure time for this type of setups can be significantly improved by implementing spectroscopic imaging sensors. The material contents in the layers can then be retrieved from the absolute and relative intensities of these two signals.

  • 9.
    Norlin, Börje
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Krapohl, David
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Fröjdh, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. CERN, Medipix Consortium, Geneva, Switzerland.
    Thungström, Göran
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Readout cross-talk for alpha-particle measurements in a pixelated sensor system2015Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 10, artikkel-id C05025Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Simulations in Medici are performed to quantify crosstalk and charge sharing in a hybrid pixelated silicon detector. Crosstalk and charge sharing degrades the spatial and spectral resolution of single photon processing X-ray imaging systems. For typical medical X-ray imaging applications, the process is dominated by charge sharing between the pixels in the sensor. For heavier particles each impact generates a large amount of charge and the simulation seems to over predict the charge collection efficiency. This indicates that some type of non modelled degradation of the charge transport efficiency exists, like the plasma effect where the plasma might shield the generated charges from the electric field and hence distorts the charge transport process. Based on the simulations it can be reasoned that saturation of the amplifiers in the Timepix system might generate crosstalk that increases the charge spread measured from ion impact on the sensor.

  • 10.
    Olsen, Martin
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Örtegren, Jonas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Zhang, Renyun
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Andersson, Henrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Olin, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Schottky model for triboelectric temperature dependence2018Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, nr 1, artikkel-id 5293Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The triboelectric effect, charging by contact, is the working principle in a device called a triboelectric nanogenerator. They are used as efficient energy transducers in energy harvesting. In such generators the charging of surfaces at contact is followed by a separation of the surfaces increasing the electrical energy which can subsequently be used. Different materials have different triboelectric potentials leading to charging at contact. The temperature dependence of the charging has just recently been studied: the triboelectric effect is decreasing with temperature for a generator of Al-PTFE-Cu. Here, we suggest a mechanism to explain this effect assuming ion transfer using a two-level Schottky model where the two levels corresponds to the two surfaces. The difference in binding energy for ions on the two surfaces then enters the formula for charging. We fit the triboelectric power density as a function of temperature obtained from a two-level Schottky model to measured data for nanogenerators made of Al-PTFE-Cu found in three references. We obtain an average separation energy corresponding to a temperature of 365 K which is of the right magnitude for physically adsorbed atoms. We anticipate that this model could be used for many types of triboelectric nanogenerators.

  • 11.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Advanced X-ray Detectors for Industrial and Environmental Applications2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The new generation of X-ray free electron laser sources arecapable of producing light beams with billion times higherpeak brilliance than that of the best conventional X-ray sources.This advancement motivates the scientific community to pushforward the detector technology to its limit, in order to de-sign photon detectors which can cope with the extreme fluxgenerated by the free electron laser sources. Sophisticated ex-periments like deciphering the atomic details of viruses, filmingchemical reactions or investigating the extreme states of matterrequire detectors with high frame rate, good spatial resolution,high dynamic range and large active sensor area. The PERCI-VAL monolithic active pixel sensor is being developed by aninternational group of scientists in collaboration to meet theaforementioned detector requirements within the energy rangeof 250 eV to 1 keV, with a quantum efficiency above 90%.In this doctoral researchwork, Monte Carlo algorithm basedGeant4 and finite element method based Synopsys SentaurusTCADtoolkits have been used to simulate, respectively, theX-rayenergy deposition and the charge sharing in PERCIVAL. Energydeposition per pixel and charge sharing between adjacent pixelsat different energies have been investigated and presented.Novel methods for industrial and environmental applica-tions of some commercially available X-ray detectors have beendemonstrated. Quality inspection of paperboards by resolv-ing the layer thicknesses and by investigating orientation ofthe cellulose fibres have been performed using spectroscopicand phase-contrast X-ray imaging. It was found that, usingphase-contrast imaging it is possible to set burn-out like qualityindex on paperboards non-destructively. X-ray fluoroscopicmeasurements have been conducted in order to detect Cr inwater. This method can be used to detect Cr and other toxicelements in leachate in landfills and other waste dumping sites.

  • 12.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Cultural contrasts affect the teacher–student relationship2017Annet (Annet (populærvitenskap, debatt, mm))
  • 13.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Grating based phase-contrast X-ray imaging technique2015Inngår i: Radiation Detectors for Medical Imaging / [ed] Jan S. Iwanczyk and Krzysztof Iniewski, CRC Press, 2015Kapittel i bok, del av antologi (Fagfellevurdert)
  • 14.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    In a non-hierarchical society far, far away from home …2017Annet (Annet (populærvitenskap, debatt, mm))
  • 15.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Phase-Contrast and Spectroscopic X-ray Imaging for Paperboard Quality Assurance2014Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The end-use performance of a paperboard depends on its quality.

    The major properties of a good quality paperboard include consistency

    in the expected ratio between the thickness of the core and

    the coating layers, and the uniformity in the coating layer. Measurement

    systems using X-rays to monitor these properties could assist

    the paperboard industries to assure the quality of their products in a

    non-destructive and automatic manner.

     

    Phase Contrast X-ray Imaging (PCXI) has been used successfully

    to look inside a wide range of objects using synchrotron radiation

    sources. Recent advancements in the grating interferometer based

    PCXI technique enables high quality phase-contrast and dark-field

    images to be obtained using conventional X-ray tubes. The darkfield

    images map the scattering inhomogeneities inside objects and

    is very sensitive to micro-structures, and thus, can reveal useful information

    about the object’s inner structures, such as, the fibre structures

    inside paperboards.

     

    In this thesis, methods, using spectroscopic X-ray imaging and

    PCXI technique have been demonstrated to measure paperboard quality.

    The thicknesses of the core and the coating layers on a paperboard

    with the coating layer on only one side can be measured using

    spectroscopic X-ray imaging technique. However, the limited

    spectral and spatial resolution offered by the measurement system

    being used led to the measured thicknesses of the layers being lower

    than their actual thicknesses in the paperboard sample. Suggestions

    have been made in relation to overcoming these limitations and to

    enhance the performance of the method.

     

    The dark-field signals from paperboard samples with different quality

    indices are analysed. The isotropic and the anisotropic scattering

    coefficients for all of the samples have been calculated. Based

    on the correlation between the isotropic coefficients and the quality

    indices of the paperboards, suggestions have been made for paperboard

    quality measurements.

  • 16.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. Deutsches Elektronen-Synchrotron (DESY).
    Report on Control/DAQ Software Design and Current State of Implementation for the Percival Detector2015Inngår i: ICALEPCS2015 - Proceedings Melbourne, Australia, 2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The Percival Collaboration is developing a high-speed,low X-ray energy detector capable of detecting single pho-tons while maintaining a large dynamic range of sensitivity.The increased brilliance of state-of-the-art Synchrotronradiation sources and Free Electron Lasers require imagingdetectors capable of taking advantage of these light sourcefacilities. The PERCIVAL ("Pixelated Energy ResolvingCMOS Imager, Versatile and Large") detector is being de-veloped in collaboration between DESY, Elettra SincrotroneTrieste, Diamond Light Source and Pohang Accelerator Lab-oratory.It is a CMOS detector targeting soft X-rays < 1 KeV, witha high resolution of up to 13 M pixels reading out at 120 Hz,producing a challenging data rate of 6 GiB/s.The controls and data acquisition system will include aSoftware Development Kit to allow integration with thirdparty control systems like Tango and DOOCS; an EPICS [1]areaDetector [2] driver will be included by default. It willmake use of parallel readout to keep pace with the datarate, distributing the data over multiple nodes to create asingle virtual dataset using the HDF5 file format for its speedadvantages in high volumes of regular data.This development project will culminate in a control andDAQ system capable of dealing with very high data rateswhile providing easy integration with site-specific controlsystems.This report presents the design of the control system soft-ware for the Percival detector, an update of the current stateof the implementation carried out by Diamond Light Source.

  • 17.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Semiconductor Radiation Detectors: Technology and Applications2017Collection/Antologi (Fagfellevurdert)
    Abstract [en]

    The aim of this book is to educate the reader on radiation detectors, from sensor to read-out electronics to application. Relatively new detector materials, such as CdZTe and Cr compensated GaAs, are introduced, along with emerging applications of radiation detectors. This X-ray technology has practical applications in medical, industrial, and security applications. It identifies materials based on their molecular composition, not densities as the traditional transmission equipment does. With chapters written by an international selection of authors from both academia and industry, the book covers a wide range of topics on radiation detectors, which will satisfy the needs of both beginners and experts in the field.

  • 18.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för elektronikkonstruktion.
    Stressed in a small group or university? Think Big!2019Annet (Annet (populærvitenskap, debatt, mm))
  • 19.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Students are stories – let us recognize them2018Annet (Annet (populærvitenskap, debatt, mm))
  • 20.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Unacknowledged supervisors – superheroes without capes2018Annet (Annet (populærvitenskap, debatt, mm))
  • 21.
    Reza, Salim
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. Deutsches Elektronen-Synchrotron (DESY).
    Chang, Haosi
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Fröjdh, Christer
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Thungström, Göran
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Detecting Cr Contamination In Water Using X-Ray Fluorescence2015Inngår i: 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, Institute of Electrical and Electronics Engineers (IEEE), 2015, artikkel-id 7581750Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    With the rapid growth in population and the overwhelming demand of industrial consumer products around the world, the amount of generated wastes is also increasing. Therefore, the optimal utilization of wastes and the waste management policies are very important in order to protect the environment[1]. The most common way of waste management is to dispose them into city dumps and landfills. These disposal sites may produce toxic and green house gases and also a substantial amount of leachate, which can affect the environment[2]. Leachate is liquid, which, while percolating through wastes in a landfill, extracts soluble and suspended solids. Leachate contains toxic and harmful substances, such as Chromium (Cr), Arsenic, Lead, Mercury, Benzene, Chloroform and Methylene Chloride, and can contaminate surface water and aquifers.

  • 22.
    Reza, Salim
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Thim, Jan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Fröjdh, Christer
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Non-Destructive Method to Resolve the Core and the Coating on Paperboard by Spectroscopic X-ray Imaging2013Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, nr 3, s. 439-442Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Quality control is an important issue in the paperboard industry. A typical sheet of paperboard contains a core of cellulose fibers [C6H10O5], coated on one or both sides with layers of calcium carbonate [CaCO3] or Kaolin [Al2Si2O5(OH)4]. One of the major properties of a good quality paperboard is the consistency of the expected ratio between the thickness of the core and the coating layers. A measurement system to obtain this ratio could assist the paperboard industry to monitor the quality of their products in an automatic manner. In this work, the thicknesses of the core and the coating layers on a paperboard with coating layer on only one side were measured using an X-ray imaging technique. However, the limited spectral and spatial resolution offered by the measurement system being used led to the measured thicknesses of the layers being lower than their actual thicknesses in the paperboard sample. Suggestions have been made in relation to overcoming these limitations and to enhance the performance of the method. A Monte Carlo N-particle code simulation has been used in order to verify the suggested method.

  • 23.
    Reza, Salim
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Pelzer, Georg
    University of Erlangen-Nuremberg, ECAP-Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany .
    Weber, Thomas
    University of Erlangen-Nuremberg, ECAP-Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany .
    Fröjdh, Christer
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Bayer, Florian
    University of Erlangen-Nuremberg, ECAP-Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany .
    Anton, Gisela
    University of Erlangen-Nuremberg, ECAP-Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany .
    Rieger, Jens
    University of Erlangen-Nuremberg, ECAP-Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany .
    Thim, Jan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Michel, Thilo
    University of Erlangen-Nuremberg, ECAP-Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany .
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Investigation on the directional dark-field signals from paperboards using a grating interferometer2014Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, s. Art. no. C04032-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent advancements in the grating interferometer based Phase Contrast X-ray Imag- ing (PCXI) technique enables high quality dark-field images to be obtained using conventional X-ray tubes. The dark-field images map the scattering inhomogeneities inside objects. Since, the dark-field image is constructed by considering only those photons which are scattered while pass- ing through the objects, it can reveal useful information about the object inner structures, such as, the fibre structures inside paperboards.

    The end-use performance of paperboards, such as the printing quality and the stiffness de-pends on the uniformity in the thickness and the structures of the coating layer of the paperboards. The uniformity in the coating layer is determined by the coating techniques, the coating materials and the topography of the base sheet. In this article, the dark-field signals from four paperboard samples with different quality indices are analysed. The isotropic and the anisotropic scattering coefficients for all of the samples have been calculated. Based on the correlation between the isotropic coefficients and the quality indices of the paperboards, a new method for paperboard quality measurement has been suggested.

  • 24.
    Reza, Salim
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Wong, Winnie
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Fröjdh, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Fröjdh, Christer
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Thungstörm, Göran
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Thim, Jan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Smart dosimetry by pattern recognition using a single photon counting detector system in time over threshold mode2012Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 7, nr 1, s. Art. no. C01027-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The function of a dosimeter is to determine the absorbed dose of radiation, for those cases in which, generally, the particular type of radiation is already known. Lately, a number of applications have emerged in which all kinds of radiation are absorbed and are sorted by pattern recognition, such as the Medipix2 application in [1]. This form of smart dosimetry enables measurements where not only the total dosage is measured, but also the contributions of different types of radiation impacting upon the detector surface. Furthermore, the use of a photon counting system, where the energy deposition can be measured in each individual pixel, ensures measurements with a high degree of accuracy in relation to the pattern recognition. In this article a Timepix [2] detector system has been used in the creation of a smart dosimeter for Alpha, Beta and Gamma radiation. When a radioactive particle hits the detector surface it generates charge clusters and those impacting upon the detector surface are read out and image processing algorithms are then used to classify each charge cluster. The individual clusters are calculated and as a result, the dosage for each type of radiation is given. In some cases, several particles can impact in roughly the same place, forming overlapping clusters. In order to handle this problem, a cluster separation method has been added to the pattern recognition algorithm. When the clusters have been separated, they are classified by shape and sorted into the correct type of radiation. The algorithms and methods used in this dosimeter have been developed so as to be simple and computationally effective, in order to enable implementation on a portable device. © 2012 IOP Publishing Ltd and SISSA.

  • 25.
    Thim, Jan
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Nawaz, Khalid
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    O´Nils, Mattias
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Oelmann, Bengt
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Suitable Post Processing Algorithms for X-Ray Imaging using Oversampled Displaced Multiple Images2011Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 6, nr 2, s. Art. no. C02001-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    X-ray imaging systems such as photon counting pixel detectors have a limited spatial resolution of the pixels, based on the complexity and processing technology of the readout electronics. For X-ray imaging situations where the features of interest are smaller than the imaging system pixel size, and the pixel size cannot be made smaller in the hardware, alternative means of resolution enhancement require to be considered. Oversampling with the usage of multiple displaced images, where the pixels of all images are mapped to a final resolution enhanced image, has proven a viable method of reaching a sub-pixel resolution exceeding the original resolution. The effectiveness of the oversampling method declines with the number of images taken, the sub-pixel resolution increases, but relative to a real reduction of imaging pixel sizes yielding a full resolution image, the perceived resolution from the sub-pixel oversampled image is lower. This is because the oversampling method introduces blurring noise into the mapped final images, and the blurring relative to full resolution images increases with the oversampling factor. One way of increasing the performance of the oversampling method is by sharpening the images in post processing. This paper focus on characterizing the performance increase of the oversampling method after the use of some suitable post processing filters, for digital X-ray images specifically. The results show that spatial domain filters and frequency domain filters of the same type yield indistinguishable results, which is to be expected. The results also show that the effectiveness of applying sharpening filters to oversampled multiple images increase with the number of images used (oversampling factor), leaving 60-80% of the original blurring noise after filtering a 6 x 6 mapped image (36 images taken), where the percentage is depending on the type of filter. This means that the effectiveness of the oversampling itself increase by using sharpening filters, and more images taken can be considered worth the effort.

  • 26.
    Thim, Jan
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    O'Nils, Mattias
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    X-ray imaging of high velocity moving objects by scanning summation using a single photon processing system2015Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, artikkel-id C04023Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    X-ray imaging has been used extensively in the manufacturing industry. In the paper and paperboard industry X-ray imaging has been used for measuring parameters such as coat weight, using mean values of X-ray absorption inline in the manufacturing machines. Recently, an interest has surfaced to image paperboard coating with pixel resolved images showing material distribution in the coating on the paperboard, and to do this inline in the paper machine. Naturally, imaging with pixel resolution in an application where the paperboard web travels with velocities in the order on 10 m/s sets harsh demands on the X-ray source and the detector system to be used. This paper presents a scanning imaging method for single photon imaging systems that lower the demands on the source flux by hundreds of times, enabling a system to be developed for high velocity industrial measurement applications. The paper presents the imaging method, a discussion of system limitations, simulations and real measurements in a laboratory environment with a moving test object of low velocity, all to verify the potential and limits of the proposed method.

  • 27.
    Thungström, Göran
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Harrnsdorf, Lars
    RTI Electronics AB, Lund University IKVM.
    Norlin, Börje
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Krapohl, David
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion.
    Mattsson, S.
    Lund University IKVM.
    Gunnarsson, M.
    Lund University IKVM.
    Measurement of the sensitive profile in a solid state silicon detector, irradiated by X-rays2013Inngår i: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 8, nr 4, s. Art. no. C04004-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A newly constructed solid state silicon dose profile detector is characterized concerning its sensitive profile. The use of the MEDIPIX2 sensor system displays an excellent method to align an image of an X-ray slit to a sample under test. The scanning from front to reverse side of the detector, show a decrease in sensitivity of 20%, which indicates a minority charge carrier lifetime of 0.18 ms and a diffusion length of 460 μm. The influence of diced edges results in a volumetric efficiency of 59%, an active volume of 1.2 mm 2 of total 2.1 mm2.

  • 28.
    Wunderer, C. B.
    et al.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Allahgholi, A.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Bayer, M.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Bianco, L.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Correa, J.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Delfs, A.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Gottlicher, P.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Hirsemann, H.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Jack, S.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Klyuev, A.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Lange, S.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Marras, A.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Niemann, M.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Pithan, F.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Reza, Salim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY, Notkestrasse 85, Hamburg, Germany .
    Sheviakov, I.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Smoljanin, S.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Tennert, M.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Trunk, U.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Xia, Q.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Zhang, J.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Zimmer, M.
    DESY, Notkestrasse 85, Hamburg, Germany .
    Das, D.
    STFC, Harwell, Oxford, Didcot, United Kingdom.
    Guerrini, N.
    STFC, Harwell, Oxford, Didcot, United Kingdom.
    Marsh, B.
    STFC, Harwell, Oxford, Didcot, United Kingdom.
    Sedgwick, I.
    STFC, Harwell, Oxford, Didcot, United Kingdom.
    Turchetta, R.
    STFC, Harwell, Oxford, Didcot, United Kingdom.
    Cautero, G.
    Elettra Sincrotrone Trieste, Basovizza, Italy.
    Giuressi, D.
    Elettra Sincrotrone Trieste, Basovizza, Italy.
    Menk, R.
    Elettra Sincrotrone Trieste, Basovizza, Italy.
    Khromova, A.
    Elettra Sincrotrone Trieste, Basovizza, Italy.
    Pinaroli, G.
    Elettra Sincrotrone Trieste, Basovizza, Italy.
    Stebel, L.
    Elettra Sincrotrone Trieste, Basovizza, Italy.
    Marchal, J.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Pedersen, U.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Rees, N.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Steadman, P.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Sussmuth, M.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Tartoni, N.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Yousef, H.
    Diamond, Harwell Campus, Didcot, United Kingdom.
    Hyun, H.
    Pohang Accelerator Laboratory, Pohang, Gyeongbuk, South Korea.
    Kim, K.
    Pohang Accelerator Laboratory, Pohang, Gyeongbuk, South Korea.
    Rah, S.
    Pohang Accelerator Laboratory, Pohang, Gyeongbuk, South Korea.
    Dinapoli, R.
    PSI, Villingen, Switzerland.
    Greiffenberg, D.
    PSI, Villingen, Switzerland.
    Mezza, D.
    PSI, Villingen, Switzerland.
    Mozzanica, A.
    PSI, Villingen, Switzerland.
    Schmitt, B.
    PSI, Villingen, Switzerland.
    Shi, X.
    PSI, Villingen, Switzerland.
    Krueger, H.
    University of Bonn, Regina-Pacis-Weg 3, Bonn, Germany .
    Klanner, R.
    University of Hamburg, Luruper Chaussee 149, Hamburg, Germany .
    Schwandt, J.
    University of Hamburg, Luruper Chaussee 149, Hamburg, Germany .
    Graafsma, Heinz
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för elektronikkonstruktion. DESY, Notkestrasse 85, Hamburg, Germany .
    Detector developments at DESY2016Inngår i: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 23, s. 111-117Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    With the increased brilliance of state-of-the-art synchrotron radiation sources and the advent of free-electron lasers (FELs) enabling revolutionary science with EUV to X-ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single-photon sensitivity with low probability of false positives and (multi)-megapixels. At DESY, one ongoing development project-in collaboration with RAL/STFC, Elettra Sincrotrone Trieste, Diamond, and Pohang Accelerator Laboratory-is the CMOS-based soft X-ray imager PERCIVAL. PERCIVAL is a monolithic active-pixel sensor back-thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90%. According to preliminary specifications, the roughly 10 cm × 10 cm, 3.5k × 3.7k monolithic sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within 27 μm pixels to measure 1 to ∼ 100000 (500 eV) simultaneously arriving photons. DESY is also leading the development of the AGIPD, a high-speed detector based on hybrid pixel technology intended for use at the European XFEL. This system is being developed in collaboration with PSI, University of Hamburg, and University of Bonn. The AGIPD allows singlepulse imaging at 4.5 MHz frame rate into a 352-frame buffer, with a dynamic range allowing single-photon detection and detection of more than 10000 photons at 12.4 keV in the same image. Modules of 65k pixels each are configured to make up (multi)megapixel cameras. This review describes the AGIPD and the PERCIVAL concepts and systems, including some recent results and a summary of their current status. It also gives a short overview over other FEL-relevant developments where the Photon Science Detector Group at DESY is involved. © 2016 International Union of Crystallography.

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