X- and gamma-ray detection with a silicon drift detector coupled to a CsI(Tl) scintillator operated with pulse shape discrimination technique

A monolithic X- and gamma-ray detector based on a silicon drift detector coupled to a CsI(Tl) scintillator is presented. The detector is operated both as a direct X-ray detector for photons interacting in silicon and as an indirect detector for photons interacting in the scintillator. As interactions in silicon and in CsI yield different amount of charge per unit energy deposited, discrimination of the place of interaction is necessary to obtain the correct energy. Discrimination of the interaction type is carried out by means of pulse shape discrimination performed with two parallel processing chains with different shaping times. In this paper an extensive characterization of the detector with temperature is presented. It is shown that cooling the detector at 10/spl deg/C allows to obtain a nearly 100% efficiency between 8 and 200 keV. Further cooling below 0/spl deg/C allows pulse shape discrimination with 100% accuracy throughout the detector's energy range. The detector has also been tested with X-rays at various energies by means of a tunable X-ray facility. These tests allowed an investigation of the light yield nonproportionality in CsI(Tl) at low energies, necessary for a proper energy calibration of the detector.

[1]  William W. Moses,et al.  Current trends in scintillator detectors and materials , 2002 .

[2]  Gianni Landini,et al.  Performances of the pulse shape electronics of the high energy experiment PDS on board the X-ray astronomy satellite SAX , 1993 .

[3]  D. Wehe,et al.  Temperature dependence of absolute CsI(Tl) scintillation yield , 1991, Conference Record of the 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference.

[4]  J. H. Hubbell,et al.  XCOM: Photon Cross Section Database (version 1.2) , 1999 .

[5]  C. Fiorini,et al.  Scintillation detection using a silicon drift chamber with on-chip electronics , 1997 .

[6]  J. Friese,et al.  The SISWICH, a detector telescope with intrinsic calibration , 1992 .

[7]  M. Marisaldi,et al.  A pulse shape discrimination gamma-ray detector based on a silicon drift chamber coupled to a CsI(Tl) scintillator: prospects for a 1 keV-1 MeV monolithic detector , 2004, IEEE Transactions on Nuclear Science.

[8]  J. D. Valentine,et al.  Light yield nonproportionality of CsI(Tl), CsI(Na), and YAP , 1997 .

[9]  F. Perotti,et al.  FIRST EXPERIMENTAL RESULTS OF A NEW GAMMA-RAY DETECTOR BASED ON A SILICON DRIFT CHAMBER COUPLED TO A SCINTILLATOR , 1998 .

[10]  Carlo Fiorini,et al.  Gamma ray spectroscopy with CsI(Tl) scintillator coupled to silicon drift chamber , 1997 .

[11]  Glenn F. Knoll,et al.  Temperature dependence of CsI(Tl) gamma-ray scintillation decay time constants and emission spectrum , 1992, Optics & Photonics.

[12]  G. Maron,et al.  A logarithmic detection system for nuclear physics , 1992 .

[13]  C. A. Stover,et al.  Giant birefringent optics in multilayer polymer mirrors , 2000, Science.

[14]  Pavel Rehak,et al.  Semiconductor drift chamber: an application of a novel charge transport scheme , 1984 .

[15]  Heike Soltau,et al.  Silicon drift detectors for high resolution room temperature X-ray spectroscopy , 1996 .

[16]  J. Valentine,et al.  Light yield nonproportionality of CsI(Tl), CsI(Na), and YAP , 1997, 1997 IEEE Nuclear Science Symposium Conference Record.

[17]  G. W. Mcbeth,et al.  Pulse shape discrimination in inorganic and organic scintillators. I , 1971 .