212Bi-212Po alpha source for the calibration and functional testing of silicon detectors: Preparation and characterisation.

Silicon detectors are widely used in space radiation dosimeter systems for measuring energetic charged particles. Calibration of such systems is usually performed with protons and heavier ions in high energy particle accelerators. For preliminary energy calibration and functional testing of silicon detectors, at any time during the development, an equipment producing a thin 212Bi-212Po alpha particle emitting source was designed and constructed. Our aim was to develop an alpha source with negligible self-shielding and short life-time in order to prevent the long-term contamination of the detectors with alpha particle emitting nuclides. In the present paper, a description of the method chosen, and the equipment developed are given. Estimates of the activity of the source produced was obtained from measurements with the RADTEL space radiation telescope under development in the Centre for Energy Research, Hungarian Academy of Sciences (MTA EK). It was also used to verify that the alpha particle emitting source is suitable for the preliminary calibration and functional testing of silicon detector systems.

An on-board TLD system for dose monitoring on the International Space Station.

This institute has developed and manufactured a series of thermoluminescence dosemeter (TLD) systems for spacecraft, consisting of a set of bulb dosemeters and a small, compact, TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A new implementation of the system will be placed on several segments of the ISS as the contribution of Hungary to this intemational enterprise. The well proven CaSO4:Dy dosemeters will be used for routine dosimetry of the astronauts and in biological experiments. The mean LET value will be measured by LiF dosemeters while doses caused by neutrons are planned to be determined by 6LiF/7LiF dosemeter pairs and moderators. A detailed description of the system is given.

Thermoluminescent dose measurements on-board Salyut type orbital stations.

A small, vibration- and shock-resistant thermoluminescent dosemeter /TLD/ system--named PILLE--was developed at the Health Physics Department of the Central Research Institute for Physics, Budapest, to measure the cosmic radiation dose on board orbital stations. The first on-board measurements with this system were performed /by B. Farkas, the Hungarian astronaut/, on the Salyut-6 space station in 1980. The same instrument was used by other crews in the following years. Doses measured at different sites in Salyut-6 are presented. The dose rates varied from 0.07 to 0.11 mGy.day-1. After the first cosmic measurements, the system was further developed. The minimum detectable dose of the new TLD system is 1 microGy, i.e. less by on order of magnitude than that of the former system. The self-irradiation dose rate of the TLD bulbs is also reduced--by more than one order of magnitude--to 10 nGy.h-1, by the use of potassium-free glass for the bulb envelope. This new type of PILLE TLD system is currently on-board Salyut-7. The dose rates /0.12-0.23 mGy.day-1/ measured in 1983 are presented in detail.

A new thermoluminescent dosimeter system for space research.

A small, portable, vibration and shock resistant thermoluminescent dosimeter system was developed to measure cosmic radiation dose on board a spacecraft. The system consists of a small battery-operated reader and a special bulb dosimeter. Doses from 10 microGy up to 100 mGy can be measured. The electrical power consumption of the reader is about 5 W, its volume is about 1 dm3 and its mass is about 1 kg. Details are given for the construction and technical parameters of the dosimeter and reader.