Use of a Metal-Nitride-Oxide-Semiconductor as the Detector for a Radiation Dosimeter.
Abstract
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 k rads to 4 M rads. Repeatability of observations indicates a precision of + or - 1% of total dose from 200 k rads to 4M rads (Si). Dosage in rads is obtained by reference to a calibrated source exposure rate and not to dose absorbed within the dosimeter. A Co60 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 20,000,000 rads did not degrade performance. Devices eventually failed due to charge migration from the large integrated circuit chip on which they were fabricated. Discrete, non-stepped gate MNOS transistors are recommended. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1978
- Accession Number
- ADA055187
Entities
People
- Ronald Guy Fraass
Organizations
- Air Force Institute of Technology