Large-area silicon drift detectors for new applications in nuclear medicine imaging
| Autor: | J. Engdahl, Wilhelm Metzger, W. Rossner, O. Boslau, J. Kemmer |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Physics
Nuclear and High Energy Physics Silicon drift detector Preamplifier business.industry Detector Collimator Scintillator law.invention Full width at half maximum Nuclear magnetic resonance Optics Nuclear Energy and Engineering law Rise time Scintillation counter Electrical and Electronic Engineering business |
| Zdroj: | IEEE Transactions on Nuclear Science. 51:1631-1635 |
| ISSN: | 0018-9499 |
| Popis: | In this paper, we have investigated the performance of a large-area (1 cm/sup 2/) square-shaped silicon drift detector (SDD) operating as an X-ray detector in direct conversion mode, as well as a photodetector in combination with a single crystal CsI:Tl scintillator (10 mm /spl times/ 10 mm /spl times/ 7 mm). An external FET, along with a low-noise charge sensitive preamplifier, was used for testing the prototype detector in the temperature range of -50 to +26/spl deg/C. In direct conversion mode, the SDD exhibited an energy resolution of 195 eV FWHM (at 5.9 keV, -23.5/spl deg/C, 4 /spl mu/s shaping time) and 170 eV FWHM (at 5.9 keV, -50/spl deg/C, 8 /spl mu/s shaping time). Pulse height spectra and signal rise times were recorded at different X-ray interaction locations across the SDD surface with the aid of a moveable collimator. Depending on collimator position, we measured signal rise times between 100 and 750 ns. After coupling the CsI-scintillator directly to the SDD surface, we obtained an excellent energy resolution of 7.0% FWHM with an uncollimated /sup 57/Co source (122 keV, -10/spl deg/C, 12 /spl mu/s shaping time). At -23.5/spl deg/C, we measured a signal rise time of approximately 25 /spl mu/s for this scintillator-SDD unit. Using a pulsed LED as excitation source, we were able to evaluate the electron drift characteristics of the tested SDD and to identify the temporal behavior of the CsI:Tl scintillator to be the dominant component of this long rise time. A short analysis regarding the different SDD signal rise times with and without scintillator will be presented. |
| Databáze: | OpenAIRE |
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