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Title: Operating characteristics of avalanche photodiodes for PET systems

Abstract

Results from recently developed avalanche photodiodes of the beveled edge type for use in low-light level applications such as PET systems are presented. Starting from a neutron transmutation doped (NTD) Si wafer, an avalanche photodiode with an active area of 100 mm{sup 2} was produced by deep Ga diffusion, followed by boron and phosphor diffusion. The gain and dark current are dependent on external voltage, and gains up to 400 are obtained at 1950 V without much excess noise, breakdown occurs at 1990 V. The detector exhibits low noise and fast response, necessary for use in PET systems. The energy resolution from a {sup 57}Co gamma-ray source was measured to be 942 eV at 6.5 keV, which corresponds to 111 r.m.s. noise electrons at the input. We measured the 3 energy resolution of the detector coupled a 3 x 3 x 3 mm{sup 3} BGO scintillator from a {sup 22}Na gamma ray source. The energy resolution at the 511 keV line was 12.5%, which is comparable to photomultiplier tubes coupled to a scintillator of the same size. Calculation of the electric field and width of the depletion region was done to estimate the thickness of the undepleted front region andmore » to optimize the quantum efficiency for detection of BGO light.« less

Authors:
 [1]; ;  [2]
  1. Universidad de Santiago (Chile)
  2. Lawrence Berkeley Lab., Berkeley, CA (United States); and others
Publication Date:
OSTI Identifier:
513091
Report Number(s):
CONF-961123-
CNN: Contract 1950450;Contract 05-95-31-GL; TRN: 97:014143
Resource Type:
Conference
Resource Relation:
Conference: Institute of Electrical and Electronic Engineers (IEEE) nuclear science symposium and medical imaging conference, Anaheim, CA (United States), 2-9 Nov 1996; Other Information: PBD: 1996; Related Information: Is Part Of 1996 IEEE nuclear science symposium - conference record. Volumes 1, 2 and 3; Del Guerra, A. [ed.]; PB: 2138 p.
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; POSITRON COMPUTED TOMOGRAPHY; PHOTODIODES; OPERATION; ENERGY RESOLUTION; NOISE; X-RAY DETECTION

Citation Formats

Gramsch, E, Gullikson, E M, and Moses, W W. Operating characteristics of avalanche photodiodes for PET systems. United States: N. p., 1996. Web.
Gramsch, E, Gullikson, E M, & Moses, W W. Operating characteristics of avalanche photodiodes for PET systems. United States.
Gramsch, E, Gullikson, E M, and Moses, W W. Tue . "Operating characteristics of avalanche photodiodes for PET systems". United States.
@article{osti_513091,
title = {Operating characteristics of avalanche photodiodes for PET systems},
author = {Gramsch, E and Gullikson, E M and Moses, W W},
abstractNote = {Results from recently developed avalanche photodiodes of the beveled edge type for use in low-light level applications such as PET systems are presented. Starting from a neutron transmutation doped (NTD) Si wafer, an avalanche photodiode with an active area of 100 mm{sup 2} was produced by deep Ga diffusion, followed by boron and phosphor diffusion. The gain and dark current are dependent on external voltage, and gains up to 400 are obtained at 1950 V without much excess noise, breakdown occurs at 1990 V. The detector exhibits low noise and fast response, necessary for use in PET systems. The energy resolution from a {sup 57}Co gamma-ray source was measured to be 942 eV at 6.5 keV, which corresponds to 111 r.m.s. noise electrons at the input. We measured the 3 energy resolution of the detector coupled a 3 x 3 x 3 mm{sup 3} BGO scintillator from a {sup 22}Na gamma ray source. The energy resolution at the 511 keV line was 12.5%, which is comparable to photomultiplier tubes coupled to a scintillator of the same size. Calculation of the electric field and width of the depletion region was done to estimate the thickness of the undepleted front region and to optimize the quantum efficiency for detection of BGO light.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1996},
month = {12}
}

Conference:
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