The thermolumiscent response of TLD 600 and TLD 700 to thermal neutrons has been measured by exposure to a monoenergetic, parallel beam, 13.8- and 81.0 meV neutrons from a Kandi II diffractometer. The integral TL response in TLD 600 for a neutron fluence of 1010 neutrons/cm2 was, after correction for self shielding, equivalent to the integral TL from 1470±90 and 4020±480 R (60Co) at E(n) = 81.0 and 13.8 meV, respectively. From these results one calculates that 1010 n/cm2 from a Maxwellian neutron energy distribution at T = 293.6°K would give an integral TL equal to 2330±145 and 2630±315 R (60Co). TLD 700 responds to a neutron fluence of 1010 81.0 meV neutrons/cm2 with an integral TL equal to that from 0.12±0.007 R (60Co), which similarly implies that 1010 Maxwellian neutrons/ cm2 at T = 293.6°K would give an integral TL signal equal to 0.19±0.011 R (60Co). The experimental results are essentially free of flux depression effects due to neutron backscattering. Monte Carlo calculations were carried out in an attempt to correct previously published results for neutron self shielding. The neutron induced Kerma is 0.135±0.01 times as effective as the 60Co induced Kerma in producing the TL in TLD 600. This ratio of efficiencies is discussed in the framework of the TL LiF dependence on linear energy transfer.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging