The LXeGRIT Compton Telescope Prototype: Current Status and Future Prospects

LXeGRIT is the first prototype of a novel concept of Compton telescope, based on the complete 3-dimensional reconstruction of the sequence of interactions of individual gamma rays in one position sensitive detector. This balloon-borne telescope consists of an unshielded time projection chamber with an active volume of 400 cm$^2 \times 7$ cm filled with high purity liquid xenon. Four VUV PMTs detect the fast xenon scintillation light signal, providing the event trigger. 124 wires and 4 anodes detect the ionization signals, providing the event spatial coordinates and total energy. In the period 1999 -- 2001, LXeGRIT has been extensively tested both in the laboratory and at balloon altitude, and its response in the MeV region has been thoroughly characterized. Here we summarize some of the results on pre-flight calibration, event reconstruction techniques, and performance during a 27 hour balloon flight on October 4 -- 5. We further present briefly the on-going efforts directed to improve the performance of this prototype towards the requirements for a base module of a next-generation Compton telescope

Performance of a Prototype of Liquid Xenon Scintillation Detector System for Positron Emission Tomography

Liquid Xe as scintillator has a very fast response. The scintillation light decays with 2.2 ns, and the recombination light for gamma-rays decayswith 45ns. Also,the scintillation yield is very high, comparable to that of Nal(Tl) crystals. These properties are considered to be advantageous for application to time of flight-position emission tomography(TOF-PET). From this perspsctive, a prototype for a TOF-PET system which consists of two identical liquid xenon detectors has been constructed using liquid Xe as scintillator material and its energy resorution, position resolution and the time resolution were measured. The energy resolutions of 29.9% and 32.4% and position resolution of 4.8mm and 9.4mm were obtained for the two identical detectors, respectively, and a time resolution of 650ps betweens the two detectors was obtained for 511keV gamma rays from position annihilation. The future development of liquid Xe TOF-PET is descussed

Noble gas detectors

This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc.The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentatio