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NEUTRON INDIVIDUAL AND AREA DOSIMETRY, REALIZATION OF NEUTRON CALIBRATION SOURCES, BETA-PARTICLE DOSIMETRY, ACCIDENT DOSIMETRY OF CLOTHES

Objective

THIS PROPOSAL WILL PROVIDE MORE INFORMATION ON DOSIMETRY FOR THE PROTECTION OF WORKERS AND THE POPULATION. PERSONAL DOSIMETRY, AREA MONITORING, SPECTROMETRY AND ACCIDENT DOSIMETRY WILL BE IMPROVED.
The work has demonstrated the feasibility of developing an operational beta dosimetry system, based on exoemissive detectors. A combined beryllium oxide/lithium fluoride detector gave very good results, for both the dose measurements and mean energy estimations concerned; the latter being determined with greater accuracy for low energies as a result of characteristic build up at these energies.

Work has been carried out in the following areas:
the estimation of mean electron energy;
thermoluminescence and exoelectron dosimetry in the tissues of cotton;
dosimetry on natural and synthetic tissue by electron spin resonance (ESR);
realisation of an operational spectrometry unit for neutrons;
the study and realisation of an individual dosimeter based on photographic emulsions;
area and individual dosimetry with proportional counters.
THIS RESEARCH PROJECT COMPRISES 6 SUB-PROJECTS ON: (A) ESTIMATION OF MEAN BETA RADIATION ENERGY BY COMPARING RESULTS OBTAINED BY THERMOLUMINESCENCE AND EXOELECTRONIC EMISSION; (B) THERMOLUMINESCENCE AND EXOELECTRONIC EMISSION DOSIMETRY OF COTTON FABRICS AFTER PHOTOTRANSFER; (C) PARAMAGNETIC ELECTRONIC RESONANCE DOSIMETRY OF NATURAL AND SYNTHETIC FABRICS; (D) DESIGN AND CONSTRUCTION OF AN "OPERATIONAL" NEUTRON SPECTOMETRY SET UP; (E) CONSTRUCTION AND TESTING OF AN INDIVIDUAL DETECTOR USING PHOTOGRAPHIC EMULSIONS; (F) ENVIRONMENTAL AND INDIVIDUAL DOSIMETRY BY PROPORTIONAL COUNTER.
A. IN THIS PROJECT WE PROPOSE TO USE LITHIUM FLUORIDE SINTERS OF KNOWN THERMOLUMINESCENCE AND EXOELECTRONIC EMISSION TO DEVELOP A DOUBLE DETECTOR-READER SET PERMITTING SIMULTANEOUS TL AND EE READING USING A SINGLE DOSIMETER.
B. THIS SECOND PROJECT IS INTENDED FOR STUDYING THERMOLUMINESCENCE PHOTOTRANSFER, (PTTL) AND EXOELECTRONIC EMISSION OF COTTON FABRICS AND SYNTHETIC FABRICS.
C. IN THIS THIRD PROJECT IT IS PROPOSED TO STUDY AND DEVELOP NEW MEASUREMENT TECHNIQUES FOR DOSIMETRY, STILL USING COTTON FABRICS OR SYNTHETIC FABRICS.
D. THE TERM "OPERATIONAL" DESCRIBES A SPECTOMETRY OF REAL RADIATION FIELDS FOUND AT WORKPLACES IN THE NUCLEAR INDUSTRY. THESE ARE GENERALLY LOW-LEVEL ENVIRONMENTS WITH LITTLE-KNOWN CHARACTERISTICS (ENERGY RANGE, INCIDENCE OF RADIATION, ETC.).
E. THE WORK OF THE SADVI AT THE CRN CORNEMBOURG (STRASBOURG) (CEC CONTRACT B10-A-522-F) HAS SHOWN THAT X-RAY FLUORESCENCE DETECTION OF THE QUANTITY OF SILVER DEVELOPED MAKES IT POSSIBLE TO DETECT NEUTRONS IN THE ENERGY RANGE BETWEEN 100 KEV AND 14 MEV.
BEFORE APPLYING THIS TECHNIQUE TO DOSIMETRY, A PHYSICAL METHOD HAS TO BE DEVELOPED FOR ELIMINATING BACKGROUND NOISE AND DISCRIMINATING GAMMA RAYS.
F. THE WORK CONSISTS IN FIRST OF ALL PRODUCING A PROPORTIONAL COUNTER ADAPTED TO ENVIRONMENTAL MEASUREMENT, HAVING A SHAPE AND COMPONENTS CONDUCIVE TO A RESPONSE IN TERMS OF DOSE EQUIVALENT AS A FUNCTION OF NEUTRON ENERGY IN CONFORMITY WITH NCRP 38. THIS COUNTER WILL BE USED FOR MAKING A PORTABLE ENVIRONMENTAL REM-METER BASED ON THE SAME PRINCIPLE AS CIRCE.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Commissariat à l'Energie Atomique (CEA)
Address
Centre D'études De Fontenay-aux-roses
92265 Fontenay-aux-roses
France