GSO Scintillators Research Articles

Czochralski growth and characterization of (Lu 1 − xGd x) 2SiO 5 single crystals for scintillators

The Czochralski growth of high quality single crystals of cerium doped mixed oxyorthosilicates, (Lu 1 − x Gd x ) 2SiO 5, where x = 0, 0.2, 0.5, 0.9, and 1.0 is reported. Their growth conditions, defects, structural stability, physical and scintillation properties versus composition have been evaluated. The mixed crystals can be an alternative to both LSO and GSO scintillators.

Development of the pulse-shape discrimination LSI for Astro-E Hard X-ray Detector

We have developed a pulse-shape discrimination LSI for the Astro-E Hard X-ray Detector (HXD). In the detector, the X-ray and non X-ray background will be reduced drastically by use of well-type phoswich counters in the compound-eye configuration. The well-type phoswich counter will use GSO(Ce) or YAP(Ce) scintillator for its detection part, and well-shaped BGO for the shielding part. The pulse-shape discriminator (PSD) described here will be used to select clean hits on the detection part, rejecting those depositing some energy in BGO. The PSD is designed as a bipolar semi-custom LSI to reduce its power consumption and size, and to enhance its reliability. The first delivery of the PSD-LSI has been tested to be acceptable for Astro-E HXD.

Neutron detection using GSO scintillator

The response of cerium-doped gadolinium orthosilicate (GSO) scintillator to thermal neutrons has been measured. A distinctive peak is observed in the pulse height spectrum at about 77 keV. It is associated with the de-excitation of the first excited states in 156Gd and 158Gd following neutron capture. Applications for thin GSO scintillators as thermal neutron detectors are proposed.

Light output and energy resolution of BGO and GSO scintillators for light ions

Abstract Light output and energy resolution of BGO and GSO crystals with photodiode readout have been measured for 1 H, 2 H and 3 He ions in the energy range of 3–15 MeV/nucleon.

Applicability of GSO scintillators for well logging

Cerium-doped gadolinium oxyorthosilicate (GSO:Ce) was developed as a scintillating material for application in positron emission tomography. The fundamental properties of this material were studied, with particular attention given to properties relevant to nuclear well logging applications and their temperature dependence. Initial evaluations indicated that this material had a number of properties which seemed to make it a favorable candidate for well logging applications, such as the reported decay-time constant of 60 ns. Subsequent studies showed the presence of a longer, 600-ns. decay constant, which, coupled with its extremely high thermal neutron absorption cross section and relatively low light output, raised questions about its suitability. The temperature dependence of GSO:Ce was investigated to better evaluate its applicability as a gamma-ray detector for nuclear well logging applications. It is noted that the main advantage of GSO, compared to other scintillators that can be used for well logging applications. is the increase in detection efficiency that can be achieved without the need for cooling the detector.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Cerium doped GSO scintillators and its application to position sensitive detectors

The dependence of the light output and the decay times of Ce-doped Gd/sub 2/SiO/sub 5/ on Ce concentration was measured. It is shown that the light output is almost constant and the decay time can be easily changed by changing Ce concentration. It is concluded that these properties make it possible to use GSO(Ce) scintillators as position-sensitive detectors.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>