Radiation Dose Analysis of NPS Flash X-Ray Facility Using Silicon Pin Diodes
Abstract
The Naval Postgraduate School (NPS) Center for Radiation Hardened Electronics conducts research in the area of electronics for Department of Defense space and strategic systems. Installed in 1988, the Flash X-ray facility uses thermoluminescent dosimeters (TLDs) as the preferred method of radiation detection for experimentation dose levels. Semiconductor devices have been practically employed as radiation detectors since the early 1960s and technology in this field has vastly improved since then. This thesis is part of the effort to seek alternate means of dosimetry for the Flash X-ray facility. Silicon photodiodes are semiconductor devices that are responsive to high-energy particles and photons. They operate by the absorption of an incident particle or photon that creates an electron-hole pair through ionization. The required energy to produce an electron-hole pair is 3.6 eV. This treed pair, under the influence of an applied electric field, generates current in the device. The amplitude of the current signal is directly proportional to the free charge created within the detector. This study correlated the output signal of commercial silicon PIN diodes to the absorbed dose of CaF(2) TLDs. The silicon PIN diodes were irradiated with photon energies of approximately 1 MeV and dose rates up to 10(exp 10) rad(Si)/s. One issue that was examined was whether measuring the waveform amplitude peak or the waveform integral would provide a more precise correlation to the TLD readings. The results showed that using voltage amplitude peak provided a more accurate correlation to the TLD readings than waveform integral results. The results overall show that PIN diode dosimetry can provide real-time measurements that will increase efficiency in performing experiments at the Flash X-ray facility. (4 tables, 22 figures, 13 refs.)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2003
- Accession Number
- ADA418593
Entities
People
- Bernard L. Jones
Organizations
- Naval Postgraduate School