Search

As a consequence of Council Directive 2013/59/EURATOM and its transposition into national law, the German States (Länder) had to define radon-prone areas where special rules apply in order to assure protection against excessive exposure to Radon-222 in living spaces and at work. The state of Saxony-Anhalt has chosen to define these areas based on datasets of long-term average indoor Rn concentration and Rn concentration in soil-air, complemented by ambient dose rate (ADR), whose values were acquired by a measurement campaign throughout the state territory.Saxony-Anhalt is characterized by sabulous lowlands in its northern part with little Rn exhalation, but also by granite in the secondary mountains of the Harz massif and copper-shale dominated areas in the south. Radon prone areas can therefore be expected in the latter regions.ADR was measured from vehicles carrying both a bGeigie nano pancake detector (the standard device of the Safecast mapping project, https://safecast.org/) with automatic GPS geo-referencing and a Thermo Eberline ESM FHZ 672-2 plastic scintillator. The latter device features a natural-background rejection system which could be used to determine high ADR levels as a consequence of K-40 anomalies that needed to be rejected. An ADR map could be created which was statistically linked to geogenic Rn data and soil geochemistry.The purpose of the resulting model is to develop an algorithm that makes ADR a predictor for identifying radon-prone areas, which is sufficiently accurate for the objective of Rn legislation. It can be used in regions lacking of indoor Rn concentration or soil-sample data, on which the identification of such areas is usually based, but whose acquisition is too time and labour consuming to be achievable in the time frame allowed for implementation of Rn legislation.It could be demonstrated that the gamma-dose rate can be used as an additional predictor for the identification of radon-prone areas with an algorithm that applies selective averaging on the data obtained on 2 500 km of measuring trips throughout the entire state of Saxony-Anhalt.In this contribution, the algorithm is presented together with the areas the State of Saxony-Anhalt has finally determined as radon prone, with the legal consequence for employers to do quality assured Radon measurements and take action with respect to radon mitigation, if necessary. Special emphasis is put on establishing a statistically significant relationship between the measured dose rate on the one hand and geological information and radon exhalation, on the other.

In view of the implementation of beam-monitoring sensors for CERN's Large Hadron Collider (LHC), and also in order to validate Thermoluminescence Detectors as a versatile tool to measure ionizing radiation doses in mixed fields at hadron colliders such as the LHC, chemical vapor deposition diamond sensors have been evaluated and calibrated at CERN's Proton Synchrotron accelerator. Special attention was paid to understanding whether lithiumfluoride thermoluminescence detectors are suitable as measuring devices in these radiation fields.

Thermoluminescent (TL) detectors are an established method for passive dose measurement. Over the last several years MCP-N (LiF:Mg,Cu,P) detectors have been widely used in modern TL dosimetry due to their very high sensitivity (at the microgray level) and their simple signal-dose relation. Their dose response does not show any supralinearity up to saturation at about 1 kGy. Only recently we have discovered their quite unexpected properties at high and ultra-high doses, which enable us to use them for measurements of doses from micrograys up to a megagray. Significant changes of the glow-curve shape occur for doses higher than a few kGy and what is most important, a new peak appears in their glow-curve at exposures above 50 kGy, the position of which shifts towards higher temperatures with increasing dose. The presented method is based on these properties. This method is also a promising way of measurements of doses in mixed radiation fields.

Contemporary particle accelerators for fundamental research in particle physics like Fermilab's Tevatron and CERN's Large Hadron Collider (LHC) provide researchers with higher and higher luminosities. This sets the pace for the need for radiation hard detector materials for both beamline instrumentation and the physics experiments themselves. Silicon pixel and silicon microstrip detectors are well developed devices for tracking applications in these high-energy physics experiments. However, these detectors are expected to reach the end of their lifetime within a few years due to their exposure to harsh radiation, of which the yearly level amounts to up to several 1014 hadrons/cm2 during the foreseen 10 years of operation in the case of LHC experiments. In order to protect sensitive experimental devices from adverse beam conditions, chemical vapor deposition (CVD) diamond, an artificially generated diamond material, is more and more being used in systems called Beam Condition Monitors (BCM). The radiation level these sensors are exposed to is even higher than in the case of position sensitive tracking detectors. An example are the CVD diamond sensors of the BCM of the LHCb experiment at CERN, which is meant to withstand 1015 hadrons/cm2 during 10 years. Preparation of CVD diamond sensors for BCM applications are discussed in detail, together with the properties of this new material as a candidate for position sensitive devices in high energy physics experiments, addressing also operational questions like the appearance of erratic dark currents in polycrystalline diamond bulks. Other new materials for position sensitive devices such as CdZnTe and CdTe are discussed as well and compared to the well established silicon, together with a compilation of their properties relevant to particle detection. Recent advances in the field of passive radiation monitors, where thermoluminescent sensors made from lithium fluoride now cover a dynamic range from several µGy up to 105Gy, are also discussed briefly.

The thermoluminescent (TL) detectors are an old-established method of passive dose measurement. In the last several years MCP-N (LiF:Mg,Cu,P) detectors have been widely used in modern TL dosimetry due to their very high sensitivity (at microgray level) and a simple signal-dose relation. Their dose response does not show any supralinearity up to saturation at about 1 kGy. Only recently we have discovered their quite unexpected properties at high and ultra-high doses, which enable us to use them for measurements of doses from micrograys up to a megagray. The presented method is based on these properties. This method is also suitable for measurements of doses in mixed radiation fields.

I am glad to be able to assist with the making of this special issue on ANIMMA 2015 again, and I would like to thank the organizers of the conference to have chosen the IEEE Transactions on Nuclear Science again for the collection of publication-grade material presented at the meeting. But I would also like to express my thanks to the Associate Editors that have conducted the peer-review process of all the manuscripts submitted in a highly professional manner. It is our goal to have every paper evaluated by at least three colleagues active in the field, and so the number of individuals that have contributed to this issue is high, again higher than in the previous years: not less than 459 colleagues have spent their valuable time by serving as reviewers for the material, whether they have attended the conference and submitted a manuscript themselves or not. It is the efficient and professional, though voluntary work, of our Associate Editors and reviewers that made this special issue become true.