ULTRA-THIN LIF-MG,CU,P DETECTORS FOR BETA-DOSIMETRY

Standard thermoluminescent (TL) detectors, owing to their relatively l arge thickness, may seriously underestimate personal skin doses which are defined at the depth of 7 mg cm(-2). New TL ultra-thin, LiF:Mg,Cu, P-based detectors have been developed at the Institute of Nuclear Phys ics to fulfil simultaneously the requirements of flat energy response for beta rays and the ability to measure low beta ray doses. In our de tectors a thin layer of MCP phosphor is bonded with a thick base of un doped LiF. We assess the effective thickness of this detector to be 8. 5 mg cm(-2). Tests of these detectors exposed with and without coverin g foil to Pm-147, Tl-204 and Sr-90/Y-90 calibrated beta fields indicat e that our detectors feature an essentially hat energy response and go od angular characteristics. The sensitivity of our detectors permits d oses in the microsievert range to be measured reliably.