The PTB Beta Secondary Standard BSS 2 for radiation protection

Abstract

With the Beta Secondary Standard (BSS), an important basis was created thirty years ago for the dissemination of the unit of the absorbed dose rate of beta radiation to tissue, which has proven its worth in practice. The main reasons for the popularity of the BSS are the traceability of its calibration to the primary standard measuring device of PTB and its conformity with the recommendations of the international standard ISO 6980. In 1996, an extensive modification of the BSS was started with the aim of improving its ease of operation, achieving a greater variety in practical use, assuring the quality when performing irradiations and optimizing radiation protection. In the following report, the result of this optimization, the new Beta Secondary Standard type 2 (BSS 2), will be presented. To this end, we will report on the investigations carried out on the BSS 2 and on the experiences gained in the work with of the BSS 2 and the calibration of -so far -32 sets of radiation sources.

Correction factors for the ISO rod phantom, a cylinder phantom, and the ICRU sphere for reference beta radiation fields of the BSS 2

“…The filter assures that the radiation field is more homogeneous in the irradiation plane than without it. It is located at a distance of 10 cm from the radiation source [7]. In the last two lines of table 1 the position of the phase space file planes (location where the simulation starts) is given.…”

Radiation Exposure of Medical Staff: Application of Hand Phantoms in Experiments and Simulations

“…Thin layer TLDs [4] were used to measure in mixed beta-gamma radiation fields, while for the X-Ray CT-measurements "Photon-TLDs" of type MTS-N [5] were employed. The "Beta-TLDs" were calibrated with a Beta Secondary Standard 2 [6], while the Photon-TLDs were calibrated according to…”

Influence of the Irradiation Systems on Beta-ray Calibration for Dosemeters

“…Two different types of beta-ray irradiation systems have been installed and served as beta reference radiation elds at the Facility of Radiation Standards (FRS) in the Japan Atomic Energy Agency (JAEA). One is so-called the Beta Secondary Standard type 2 (BSS2), 1) which is commercially available and commonly used worldwide as a de facto standard in beta calibration. The BSS2 was newly installed in 2010 at the JAEA-FRS.…”

“…For a dosemeter composed of low-Z meterials, the same ,Sr + Y sys (7 mg/cm 2 ) (mGy/h) * 1 79.4 ± 0.9 * 2 34.5 ± 0.7 * 2 * 1 These values were obtained directly from the measurements using extrapolation chamber. * 2 As of 13 th November 2013 and the associated uncertainties are given for k = 1. equation can be applied by replacing the values u and d 1 with their tissue-equivalent ones which is obtained by multiplying the scaling factor relative to the tissue given in ISO 6980-2.…”