Evaluation of lithium borate as a 7000-R dosimeter

Abstract

vponiorrd ht i he I'mtnl Si»tr> (Htvprnmrnl. Nuthur ih> I'm led Statru nor tttr ( mted State* f.'nrrifv R^nearch and OrvrlopmrM AdminiHtralinn, nor an\ of ihrir *mp1ov^*». nor an\ of thpir con-(ru<'lors, siibtunlrBctorit. or (knr pmplnvNi. makn «n> warrantv. *»prnt* or implied, or mum'* *n\ lefai li»bilil\ or rMponnbilitv for thr arruract oompl*irnnit. or uwfulnM* of anx informuiion. apparaiui, product, or pruorieH diu-loKMl, or reprewnu Itiai m uir would not wtrtnff pnvatriy owned ih NOTICE This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Lnergy Research and Development Administration, nor any of their employees, nor any of their contractor*, subcontractors, or their employees, makes any warranty, impress or implied, o/ assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. EVALUATION OF LITHIUM BCIRATF. AS ABSTRACTThe Harshaw Model 2271 TL Detector/Dosimeter system with lithium borate dosimeters was evaluated as a 7000-R dosimetry system. One hundred dosimeter cards having two dosimeters per card were irradiated up to ninety-eight times with x rays from a 250-keV (electron energy) GE x-ray machine.A twofold change in calibration was observed during the course of 98 irradiation cycles and a decrease in light output versus time lag between irradiation and reading was observed. The first card "failed" on the 36th cycle and only two cards survived to the 98th cycle. All of the failures were due to damage of the Teflon packaging, causing the dosimeters to hang up in the readout or to move in their card.This system could be used for screwworm fly dosimetry but is not considered ideal.