An Automatic Lithium Drifting Apparatus for Silicon and Germanium Detectors

Conference · Sat Feb 08 04:00:00 EST 1964

OSTI ID:887450

Goulding, Fred S.; Hansen, W. L.

Drifting a thick lithium-drifted counter (silicon and germanium) is a time-consuming operation that frequently results in a poor device, owing to inadequate knowledge of progress of the drifting operation. The drifting apparatus described here automatically controls the temperature of the detector that is being drifted to maintain the leakage current at a preselected value. While drifting proceeds, a continuous measurement is made of the distance of the lithium-drifted region from the opposite face of the wafer. When the drifted region reaches 30 mil or less from the back of the wafer a meter indicates the thickness of the undrifted region and, when this thickness falls below a preselected value, the temperature of the detector is automatically reduced to room temperature. The need for constant supervision of the drifting operation is thereby eliminated, and reliance on theoretical drift-rate calculations to predict the drift-through time is avoided. The technique has been applied to the manufacture of lithium-drifted silicon detectors with excellent results. The application of the technique to lithium-drifted germanium {gamma} detectors is also discussed briefly.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USAEC
• DOE Contract Number: W-7405-ENG-48; AC02-05CH11231
• OSTI ID: 887450
• Report Number(s): UCRL--11261; CONF-182-8
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
GE SEMICONDUCTOR DETECTORS
LEAKAGE CURRENT
LITHIUM
SCINTILLATIONS
SI SEMICONDUCTOR DETECTORS
TEMPERATURE CONTROL