THE IMPACT OF NEW ICRU95 QUANTITIES AND SPECTRUM DATA ON THE DOSIMETRIC QUANTITIES OF THE NEUTRON REFERENCE FIELDS AT PTB.

In 2020, the ICRU released a new report which includes the re-definition of the operational quantities used in radiation protection and new conversion coefficients from physical quantities to operational radiation protection quantities. An assessment of the ambient and personal dose conversion coefficients for the reference neutron fields of radionuclide sources at PTB is necessary based on these new definitions. In this work, a numerical estimation of the conversion coefficients of moderated and unmoderated 252Cf and 241Am-Be neutron sources based on ICRU57 and ICRU95 reports and using spectrum data available in the ISO 8529-1 standard and at PTB are discussed.

CALCULATIONS FOR THE HEAVY WATER MODERATED 252CF REFERENCE FIELDS AT PTB.

Knowledge of the neutron spectra of reference fields is very important for calibration purposes. This paper presents new calculations of the neutron spectra and dosimetric parameters of a D2O moderated 252Cf source assembly used to produce a neutron reference field at the Physikalisch-Technische Bundeanstalt (PTB), based on recent 252Cf fission neutron spectrum data and conversion coefficients for operational radiation protection units recommended by the International Commission on Radiological Protection (ICRP) report 57. Neutron fluence and dose calculations were carried out using a detailed simulation model of the source assembly implemented using MCNP6 and the cross-section data library ENDF/B-VIII.

CHARACTERISATION OF THE PTB THERMAL NEUTRON CALIBRATION FACILITY WITH THE BONNER SPHERE SPECTROMETER NEMUS.

The neutron field of the PTB Thermal Neutron Calibration Facility was characterised with the help of the Bonner sphere spectrometer of PTB, NEutron MUltisphere Spectrometer (NEMUS). For the analysis of the Bonner sphere data an analytical model of the neutron energy distribution was used. The unfolding of neutron spectra was performed via the method of Bayesian parameter estimation.

REVISION OF ISO 8529-REFERENCE NEUTRON RADIATIONS.

ISO Standard 8529, on Reference neutron radiations, is due for revision. This paper covers proposed changes to Part 1 which dates from 2001. The changes are mainly designed to improve the data on radionuclide source neutron spectra, but also include options for modifying the content, e.

Overview of diagnostic performance and results for the first operation phase in Wendelstein 7-X (invited).

Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters in December 2015. At the end of the 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were in operation, allowing detailed studies of many interesting plasma phenomena.