Bismuth germanate as a high-energy gamma-ray detector

Journal Article · Fri Apr 01 00:00:00 EST 1983 · IEEE Trans. Nucl. Sci.; (United States)

DOI:https://doi.org/10.1109/TNS.1983.4332580· OSTI ID:5609579

Wender, S A

For the past several years the majority of experiments that detected gamma-rays above 10.0 MeV involved large volume NaI detectors with anticoincidence shields surrounding them. These shields serve two purposes: first, they veto cosmic ray events, and second, they reject gamma-ray events that do not deposit their total energy in the crystal. Recently bismuth germanate (Bi/sub 4/Ge/sub 3/O/sub 12/), or BGO, scintillators have been developed with many properties that may make them an attractive alternative to NaI in many applications. In this particular experiment the authors detect gamma rays following high-energy neutron capture using a white neutron source. The requirements of detector system are that it have good energy and time resolution, high efficiency, and low sensitivity to neutron backgrounds. Since the authors require an array of detectors to simultaneously measure the angular distribution of the radiation along with the excitation function, NaI detectors with anticoincidence shields seem impractical. They therefore decided to construct a detector system consisting of five 7.6-cm-long by 7.6-cm-diam-BGO scintillators spanning an angular range from 140 to 45 degrees in the reaction plane. A table lists some of the properties of BGO/sup 4/ and the values for NaI for comparison. For present application the advantages of BGO are its high average atomic number and its large density. Both these factors contribute towards improving the detector efficiency. The disadvantages of BGO are its lower light output (1/10 of NaI), its high index of refraction (n = 2.15), and its longer wavelength at maximum light output. In addition large BGO crystals often contain trapped bubbles, which scatter the light. All these factors tend to limit the resolution of the scintillator.

• Research Organization: Los Alamos National Lab, Los Alamos, NM 87545
• OSTI ID: 5609579
• Journal Information: IEEE Trans. Nucl. Sci.; (United States), Vol. 30:2
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
GAMMA DETECTION
SOLID SCINTILLATION DETECTORS
BISMUTH GERMANATES
GAMMA RADIATION
MEV RANGE 10-100
RESOLUTION
SODIUM IODIDES
ALKALI METAL COMPOUNDS
BISMUTH COMPOUNDS
DETECTION
ELECTROMAGNETIC RADIATION
ENERGY RANGE
GERMANATES
GERMANIUM COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
INORGANIC PHOSPHORS
IODIDES
IODINE COMPOUNDS
IONIZING RADIATIONS
MEASURING INSTRUMENTS
MEV RANGE
OXYGEN COMPOUNDS
PHOSPHORS
RADIATION DETECTION
RADIATION DETECTORS
RADIATIONS
SCINTILLATION COUNTERS
SODIUM COMPOUNDS
440101* - Radiation Instrumentation- General Detectors or Monitors & Radiometric Instruments