LiF Thermoluminescent Detectors Research Articles

Neutron Response of LiF TL Detectors

For the application of thermoluminescent (TL) detectors in neutron dosimetry the detector response over the whole energy range must be known. Therefore the energy deposition by secondary ions and gamma radiation generated as a result of neutron interactions in the detector material or in the surrounding material (detector holder, radiator) is of fundamental importance. The different neutron response components can be calculated by means of computer programs. This paper deals with the method and results of response calculations. The effect of the absorbed dose caused by heavy charged particles to the detector reading (so-called light conversion factors) were experimentally determined for various ions and TL materials. The knowledge of these effects allows the calculation of the intrinsic response as well as of the response component caused by heavy charged particles from a hydrogen containing radiator. For different TL detectors the calculated responses are compared with experimental data in neutron fields. The experimental and theoretical results are in a good agreement.

Neutron Response of LiF TL Detectors

For the application of thermoluminescent (TL) detectors in neutron dosimetry the detector response over the whole energy range must be known. Therefore the energy deposition by secondary ions and gamma radiation generated as a result of neutron interactions in the detector material or in the surrounding material (detector holder, radiator) is of fundamental importance. The different neutron response components can be calculated by means of computer programs. This paper deals with the method and results of response calculations. The effect of the absorbed dose caused by heavy charged particles to the detector reading (so-called light conversion factors) were experimentally determined for various ions and TL materials. The knowledge of these effects allows the calculation of the intrinsic response as well as of the response component caused by heavy charged particles from a hydrogen containing radiator. For different TL detectors the calculated responses are compared with experimental data in neutron fields. The experimental and theoretical results are in a good agreement.

Measurement of dose in the buildup region using fixed‐separation plane‐parallel ionization chambers

Accurate measurement of dose at the surface of a phantom and in the buildup region is a difficult task but one that is important for the proper treatment of patients. The instruments of choice for these measurements are extrapolation chambers but few institutions have these instruments at their disposal. As a result, fixed-separation plane-parallel ionization chambers are most commonly used for this purpose. Recent papers have re-emphasized the inaccuracies in the measurement of dose in the buildup region of normally incident photon beams when using fixed-separation plane-parallel ionization chambers. Data for Co-60, 6-, 10-, 18-, and 24-MV photon beams are presented that show the magnitude of this over response in the buildup region for several commercially available plane-parallel ionization chambers versus results obtained using both an extrapolation chamber and LiF thermoluminescent detectors. Differences in the percent depth dose at the surface of a phantom of greater than 19% were found for one of the chambers. All chambers over responded in the buildup region to some degree based upon their internal dimensions. The appropriateness of published corrections for these chambers is evaluated and guidelines for the accurate measurement of dose in the buildup region are presented.

Apparatur zur kontinuierlichen Auswertung fadenförmiger Thermoluminsezenzdosimeter

Construction and functioning of a device for readout thread-shaped LiF-thermoluminescent detectors is described. These detectors serve as measurement of distribution of absorbed dose in affected organs (kidney, ureter, bladder, rectum) with radiation treatment of gynaecologycal tumors.

Calculations of Responses to Representative Neutron Spectra of Albedo Neutron Dosemeters Incorporating LiF Thermoluminescent Detectors

The responses to representative neutron spectra from the Health Physics Research Reactor in the USA of some albedo dosemeter configurations using commercially available LiF TLD chips have been calculated, and methods suggested for correcting the energy response of albedo dosemeters.

Influence of Light Transmission on the Response of LiF Thermoluminescence Detectors to Thermal Neutrons

Influence of Light Transmission on the Response of LiF Thermoluminescence Detectors to Thermal Neutrons

Response of LiF (TLD-700) thermoluminescence detectors to pions and high-energy neutrons

A double readout method for 7LiF (TLD-700) at 250°C and 300°C was used for dosimetry in pion and high-energy neutron beams in comparison with tissue-equivalent ionization chambers. The LET (linear energy transfer) dependence of the ratio of the readout values can be used as a radiation quality parameter.