X-ray and gamma ray detector readout system

Patent · Tue Oct 19 00:00:00 EDT 2010

OSTI ID:1016123

Tumer, Tumay O ^[1]; Clajus, Martin ^[2]; Visser, Gerard ^[3]

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1. Riverside, CA
2. Los Angeles, CA
3. Bloomington, IN

A readout electronics scheme is under development for high resolution, compact PET (positron emission tomography) imagers based on LSO (lutetium ortho-oxysilicate, Lu.sub.2SiO.sub.5) scintillator and avalanche photodiode (APD) arrays. The key is to obtain sufficient timing and energy resolution at a low power level, less than about 30 mW per channel, including all required functions. To this end, a simple leading edge level crossing discriminator is used, in combination with a transimpedance preamplifier. The APD used has a gain of order 1,000, and an output noise current of several pA/ Hz, allowing bipolar technology to be used instead of CMOS, for increased speed and power efficiency. A prototype of the preamplifier and discriminator has been constructed, achieving timing resolution of 1.5 ns FWHM, 2.7 ns full width at one tenth maximum, relative to an LSO/PMT detector, and an energy resolution of 13.6% FWHM at 511 keV, while operating at a power level of 22 mW per channel. Work is in progress towards integration of this preamplifier and discriminator with appropriate coincidence logic and amplitude measurement circuits in an ASIC suitable for a high resolution compact PET instrument. The detector system and/or ASIC can also be used for many other applications for medical to industrial imaging.

• Research Organization: Nova R&D, Inc. (Riverside, CA)
• Sponsoring Organization: USDOE
• DOE Contract Number: FG03-00ER83058
• Assignee: Nova R&D, Inc. (Riverside, CA)
• Patent Number(s): 7,818,047
• Application Number: 10/291,251
• OSTI ID: 1016123
• Country of Publication: United States
• Language: English