Metal-Nitride-Oxide-Semiconductor Detector for an Ionizing Radiation Dosimeter.
Abstract
This report describes the work completed by the author for his Master of Science thesis at the Air Force Institute of Technology. The topic and funds were provided by the Air Force Weapons Laboratory. A method of radiation dosimetry using a Metal-Nitride-Oxide-Semiconductor (MNOS) device as the detector was developed and partially evaluated. The MNOS devices are capable of measuring doses from 10 krds to 4 Mrds. Repeatability of observations indicates a precision of = 1 percent of total dose from 200 krds to 4 Mrds (Si). Dosage in rads (rds) is obtained by reference to a calibrated source exposure rate and not to dose absorbed within the dosimeter. A Co 60 source was used for all radiation testing. Schematics are given for some of the circuits tested. Determination of dosage from the system is indirect and requires the use of a Calibration curve. Each dosimeter must be calibrated from a known source. Direct readout of dose is suggested by use of a microprocessor. Exposure to 2 x 10 to the 7th power rds did not degrade performance. Devices eventually failed due to charge migration from the large integrated circuit chip on which they were fabricated. Discrete, nonstepped gate MNOS transistors are recommended.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1978
- Accession Number
- ADA065995
Entities
People
- Ronald G. Fraass
Organizations
- Air Force Research Laboratory