Fading Tracks

Latent Image Fading in Personnel Neutron Monitoring Film Exposed to a Moderated 238PuO2 Source

Latent image fading in neutron monitoring film was investigated for two weeks. One hundred and twenty pieces of neutron film were packaged in film badges and exposed to a moderated 238PuO2 source at various time intervals. The daily exposure data indicated that there was 16% fading of neutron tracks after one week and 30% fading of neutron tracks after two weeks. Also, the weekly exposure data indicated that films receiving equal exposure for one week and developed on the second day of the following week has 17% fading of neutron tracks. Similarly, films receiving equal exposure for two sconsecutive weeks and developed on the second day of the third week had 30% fading of neutron tracks. The one- and two-week exposures approximate the radiation exposure which could be received by personnel exposed to neutron radiation in a 238PuO2 process area. The combined results of latent image fading studies indicated that fading in neutron monitoring film cannot be accurately predicted on the basis of average energy alone.

A Study of Charged Particle Tracks in Cellulose Nitrate

Both experimental and theoretical contributions are presented on the topic of dielectric charged particle track detectors. Cellulose nitrate was the principal track recording material. The study covers four areas: The chemical etch development of tracks; Track registration criteria; Range-energy calculations and comparisons with the etched tracks lengths; Charged particle detection.

Solid State Nuclear Track Detectors