scholarly journals Dose Rate Measurements in Pulsed Radiation Fields by Means of an Organic Scintillator

2021 ◽  
Vol 253 ◽  
pp. 09002
Author(s):  
Theresa Werner ◽  
Roland Beyer ◽  
Richard Biedermann ◽  
Marko Gerber ◽  
Jürgen Götze ◽  
...  
Keyword(s):  
Digital Data ◽  
Laser Machining ◽  
Dose Equivalent ◽  
Organic Scintillator ◽  
Radiation Fields ◽  
Medical Diagnostic ◽  
Ambient Dose Equivalent ◽  
Short Time ◽  
Ambient Dose

A deficiency in the implementation of current radiation protection is the determination of the ambient dose equivalent H*(10) and the directional dose equivalent H´(0.07) in pulsed radiation fields. Conventional dosimeter systems are not suitable for measurements in photon fields comprising short radiation pulses, which consequently leads to high detector loads in short time periods. Nevertheless, due to the implementation of advanced medical accelerators for cancer therapy, new medical diagnostic devices as well as various laser machining systems, there is an urgent need for suitable dosimeter systems for real time dosimetry. In this paper, a detector concept based on an organic scintillator and a full digital data analysis with the aim of developing a portable, battery powered measurement system is presented.

scholarly journals Ambient dose equivalent measurements in secondary radiation fields at proton therapy facility CCB IFJ PAN in Krakow using recombination chambers

Nukleonika ◽  
2016 ◽  
Vol 61 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Edyta A. Jakubowska ◽  
Michał A. Gryziński ◽  
Natalia Golnik ◽  
Piotr Tulik ◽  
Liliana Stolarczyk ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Gamma Probe ◽  
Secondary Radiation ◽  
Dose Equivalent ◽  
Radiation Fields ◽  
Tissue Equivalent ◽  
Ambient Dose Equivalent ◽  
Dosimetric System ◽  
Ambient Dose

AbstractThis work presents recombination methods used for secondary radiation measurements at the Facility for Proton Radiotherapy of Eye Cancer at the Institute for Nuclear Physics, IFJ, in Krakow (Poland). The measurements ofH*(10) were performed, with REM-2 tissue equivalent chamber in two halls of cyclotrons AIC-144 and Proteus C-235 and in the corridors close to treatment rooms. The measurements were completed by determination of gamma radiation component, using a hydrogen-free recombination chamber. The results were compared with the measurements using rem meter types FHT 762 (WENDI-II) and NM2 FHT 192 gamma probe and with stationary dosimetric system.

DEVELOPMENT OF A NEW SECONDARY STANDARD FOR H*(10)

2020 ◽  
Vol 188 (3) ◽  
pp. 378-382
Author(s):  
K Bairlein ◽  
B Behnke ◽  
O Hupe
Keyword(s):  
Ionization Chamber ◽  
Secondary Standard ◽  
Dose Equivalent ◽  
Air Kerma ◽  
Radiation Fields ◽  
Ambient Dose Equivalent ◽  
Conversion Coefficients ◽  
Aluminium Coating ◽  
Pulsed Fields ◽  
Ambient Dose

Abstract A secondary standard for ambient dose equivalent, H*(10), is necessary for the dissemination of the unit Sievert (Sv), but there is no such standard commercially available currently. Furthermore, the measurement of H*(10) instead of calculating H*(10) from air kerma and conversion coefficients is needed for unknown radiation fields. We developed a prototype of a new secondary standard for H*(10) based on a spherical 1 l ionization chamber for air kerma. This chamber was modified with copper wires at the inner surface to adjust the response of the chamber according to H*(10). Additionally, a Makrolon shell and an aluminium coating were added to optimize the response at energies below 50 keV. The prototype fulfils the requirements given in ISO 4037-2 in the energy range from 12 keV to 7 MeV. In combination with an electrometer, it can be used as area dosemeter, suitable for pulsed fields and for low energy radiation.

The Design of an Ambient Neutron Dose-Equivalent Meter

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Xia Wenming ◽  
Jia Mingchun ◽  
Guo Zhirong
Keyword(s):  
Neutron Radiation ◽  
Monte Carlo Code ◽  
Energy Response ◽  
Dose Equivalent ◽  
Neutron Dosimeter ◽  
Radiation Fields ◽  
Ambient Dose Equivalent ◽  
Ambient Dose ◽  
Detector Design ◽  
Single Counter

At present, most of the developed neutron dosimeters used to measure the neutron ambient dose-equivalent that has a moderator with a single counter, applied in neutron radiation fields within large range energies from thermal to MeV neutrons, are not a satisfaction to energy response. The purpose of this article is to design a suitable neutron dosimeter for radiation protection purpose. In order to overcome the disadvantage of the energy response of the neutron dosimeters combining a single sphere with a single counter, three spheres and three H3e counters were combined for the detector design. The response function of moderators with different thicknesses combined with SP9 H3e counters were calculated with Monte Carlo code MCNP 4C. The selection of three different thicknesses of the moderating polyethylene sphere was done with a MATLAB program. A suitable combination of three different thicknesses was confirmed for the detector design. The electronic system of the neutron dosimeter was introduced. The results of ambient dose-equivalent per unit fluence in different radiation areas were calculated, analyzed, and compared with the values recommended in the ISO standard. The calculated result explains that it is very significant to this design of neutron dosimeter; it may be applied to the monitor of the ambient dose in the neutron radiation fields, improving at present the status of the energy response of neutron dosimeters.

Determination of the Effective Dose on X-ray Inspection Systems Based on Measurements of Air Kerma or Ambient Dose Equivalent

ANRI ◽  
2020 ◽  
pp. 16-24
Author(s):  
S. Baru ◽  
V. Kravchenko ◽  
V. Leonov ◽  
P. Papushev ◽  
V. Porosev
Keyword(s):  
Effective Dose ◽  
Accurate Determination ◽  
Photon Radiation ◽  
Dose Equivalent ◽  
X Ray ◽  
Air Kerma ◽  
Ambient Dose Equivalent ◽  
Inspection Systems ◽  
Ambient Dose

The purpose of this work was to determine the transition coefficients from measured values in practice – air kerma or ambient dose equivalent to the effective dose of radiation on inspection systems using X-ray radiation, in particular, for the installation «Sibscan». This paper presents the results of Monte Carlo calculations using the GEANT4 simulation package and the MIRD and ICRP anthropomorphic phantoms. It was shown that when calculations are based on measurements of the kerma in the air, it is necessary to use the multiplier 1.05 (Sv/Gy) when a person is irradiated in anteroposterior projection and 0.65 (Sv/Gy) in posteroanterior projection. In calculations based on measurements of the ambient dose equivalent H*(10), it is necessary to take into account the conversion constant H*(10)/Kerma, equal to 1.62 (Sv/Gy) and use the coefficients 0.65 (Sv/Sv) and 0.4 (Sv/Sv) in the specified projections respectively. For a more accurate determination of the effective dose, it is necessary to take into account a larger set of technical parameters of the system. Thus, it is necessary to declare not only the maximum voltage at the radiation source but also the thickness of the half-attenuation layer in aluminum as a measure of the applied photon radiation filtering. The obtained coefficients could be used in estimating the effective radiation doses on real installations.

scholarly journals APPLICATION OF THE MCNP6.1 CODE TO ESTIMATE THE DIRECTIONAL DEPENDENCE OF RADIATION PROTECTION FACTOR VALUES FOR A SIMPLE SURROGATE VEHICLE

2020 ◽  
Vol 189 (1) ◽  
pp. 89-97
Author(s):  
Stephen R McHale ◽  
Andrew W Decker ◽  
Blake K Huff
Keyword(s):  
Radiation Protection ◽  
Energy Deposition ◽  
Incident Field ◽  
Dose Equivalent ◽  
Protection Factor ◽  
Radiation Fields ◽  
Support Organizations ◽  
Energetic Radiation ◽  
Ambient Dose Equivalent ◽  
Ambient Dose

Abstract Radiation protection factor (RPF) values are relevant to various US defense and civil support organizations. An equation was developed to quantify the angular-dependent protection of a shielding configuration in the presence of a mono-energetic radiation field. Values of ambient dose equivalent, H*(10), were computed with version 6.1 of the Monte Carlo N-Particle Code (MCNP6.1) for more than 70 distinct, mono-energetic, planar photon and neutron fields using both the kerma approximation and energy deposition from primary and secondary radiations. The two computational approaches were compared, and the MCNP6.1 models were then modified to simulate the same radiation fields and compute values of directional dose equivalent, H′(10,α), in a tissue sphere centered inside a surrogate vehicle for 13 angles of incidence. Values of H*(10) and H′(10,α) were recast as energy- and angular-dependent RPF values for the incident field–shielding geometries and tabulated. Examples of implementation are provided, and limitations are discussed.

scholarly journals Primary reference in terms of air kerma for ionizing radiation fields produced by an electrostatic electron accelerator

2019 ◽  
Author(s):  
Jean-Marc Bordy ◽  
Valentin Blideanu ◽  
Arnaud Chapon ◽  
Gabriel Dupont ◽  
Dorin Dusciac ◽  
...  
Keyword(s):  
International System ◽  
X Rays ◽  
Dose Equivalent ◽  
Air Kerma ◽  
Radiation Fields ◽  
Tantalum Target ◽  
System Of Units ◽  
Ambient Dose Equivalent ◽  
Primary Reference ◽  
Ambient Dose

Based on a radiation field produced by an electrostatic accelerator, a radiation survey meter test and calibration facility has been designed and characterized in terms of air kerma and ambient dose equivalent. The electron beam impinges a tantalum target to produce X-rays. The spectrum has been measured and calculated. Traceability to the International System of units is achieved by means of a calibration with a primary dosimeter for air kerma.

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