The tuning algorithms used by the Donner 600 Crystal Tomograph

Conference · Tue Nov 01 00:00:00 EST 1988

OSTI ID:6352773

Moses, W W; Derenzo, S E; Geyer, A B; Huesman, R H; Uber, D C

We describe the computer algorithms used to adjust the energy thresholds and timing delays in the Donner 600 Crystal Tomograph. These thresholds and delays are adjusted using 1890 computer controlled digital to analog converters (DAC's) and a orbiting positron source. The energy threshold for each crystal is adjusted by measuring the counting rate of each crystal-crystal coincidence as a function of the DAC settings that control a pulse height window for the crystal in question. The DAC settings that correspond to the 511 keV photopeak are noted, thus determining the conversion from DAC setting to energy, and allowing the DAC's to be set to any desired energy window. The DAC settings controlling the timing delay for each channel are systematically adjusted to maximize the overall event rate. As these 1890 adjustments are coupled, we discuss the convergence of the tuning algorithms, and also report on the photomultiplier tube gain and timing variations over a period of 18 months. 7 refs., 6 figs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6352773
• Report Number(s): LBL-26501; CONF-881103-41; ON: DE89007133
• Resource Relation: Conference: IEEE nuclear science symposium, Orlando, FL, USA, 9 Nov 1988; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
POSITRON COMPUTED TOMOGRAPHY
ALGORITHMS
COMPUTERIZED CONTROL SYSTEMS
DIGITAL-TO-ANALOG CONVERTERS
TUNING
COMPUTERIZED TOMOGRAPHY
CONTROL SYSTEMS
DIAGNOSTIC TECHNIQUES
ELECTRONIC EQUIPMENT
EMISSION COMPUTED TOMOGRAPHY
EQUIPMENT
MATHEMATICAL LOGIC
TOMOGRAPHY
550602* - Medicine- External Radiation in Diagnostics- (1980-)
990220 - Computers
Computerized Models
& Computer Programs- (1987-1989)