Modeling of Laboratory Animals Exposure Conditions behind Local Concrete Shielding Bombarded by 650-MeV Protons

2021 ◽  
Vol 65 (5) ◽  
pp. 77-86
Author(s):  
A Ivanov ◽  
A Krylov ◽  
A. Molokanov ◽  
A. Bushmanov ◽  
A. Samoylov
Keyword(s):  
Absorbed Dose ◽  
High Energy ◽  
Laboratory Animals ◽  
Diamond Detector ◽  
Radiation Fields ◽  
The Monte Carlo Method ◽  
Direct Measurements ◽  
Pass Through ◽  
Protective Structures ◽  
Dose Measurements

Purpose: To estimate the radiation fields formed after the passage of high-energy protons through the concrete protection for subsequent radiobiological experiments on animals on this model. Material and methods: The results of the calculation of the secondary characteristics of a field of mixed radiation behind the local concrete with thickness 20, 40, and 80 cm, bombarded by a proton beam of 650 MeV at the JINR Phasotron and experimental estimation of the values of the absorbed dose phantoms of mice irradiated for protection during radiobiological experiments. The calculation was performed by the Monte Carlo method according to the MCNPX program for secondary protons, neutrons, π-mesons, and gamma rays. To verify the adequacy of calculations was performed the comparison of calculated and measured in the experiment spatial distribution of activation threshold detectors for aluminum protection, as well as a comparison of the calculated values of absorbed dose for radiation protection with the results of absorbed dose measurements with a diamond detector. Results: The calculations made it possible to obtain the characteristics of the fields of mixed secondary radiation behind local concrete shields of different thickness irradiated with protons with an energy of 650 MeV and to estimate the values of absorbed doses in the irradiation sites of mice in the radiobiological experiment. The reliability of the calculations was confirmed by experimental verification of the activation of aluminum threshold detectors behind a 20 cm thick protection, as well as direct measurements using a diamond detector. Conclusion: The calculated assessment of radiation fields formed after protons pass through the concrete protection and its comparison with the results of radiation dose measurements for the subsequent radiobiological experiment on animals on this model in the interests of designing protective structures on the Moon and other space bodies, as well as biological defenses on charged-particles accelerators.

scholarly journals Review of surface dose detectors in radiotherapy

2003 ◽  
Vol 3 (2) ◽  
pp. 69-76 ◽  
Author(s):  
E. O'Shea ◽  
P. McCavana
Keyword(s):  
Absorbed Dose ◽  
High Energy ◽  
Skin Dose ◽  
Surface Dose ◽  
Radiographic Film ◽  
Equilibrium Conditions ◽  
Diamond Detector ◽  
Thermoluminescent Dosimeters ◽  
Absorbed Radiation Dose ◽  
Dose Measurements

Several instruments have been used to measure absorbed radiation dose under non-electronic equilibrium conditions, such as in the build-up region or near the interface between two different media, including the surface. Many of these detectors are discussed in this paper. A common method of measuring the absorbed dose distribution and electron contamination in the build-up region of high-energy beams for radiation therapy is by means of parallel-plate ionisation chambers. Thermoluminescent dosimeters (TLDs), diodes and radiographic film have also been used to obtain surface dose measurements. The diamond detector was used recently by the author in an investigation on the effects of beam-modifying devices on skin dose and it is also described in this report.

scholarly journals Diamond detector in absorbed dose measurements in high‐energy linear accelerator photon and electron beams

2016 ◽  
Vol 17 (2) ◽  
pp. 291-303 ◽  
Author(s):  
Ramamoorthy Ravichandran ◽  
John Pichy Binukumar ◽  
Iqbal Al Amri ◽  
Cheriyathmanjiyil Antony Davis
Keyword(s):  
Linear Accelerator ◽  
Electron Beams ◽  
Absorbed Dose ◽  
High Energy ◽  
Diamond Detector ◽  
Dose Measurements

scholarly journals Ionization Dosimetry Principles for Conventional and Laser-Driven Clinical Particle Beams

2018 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Ionizing Radiation ◽  
Heavy Particle ◽  
Absorbed Dose ◽  
High Energy ◽  
Particle Energy ◽  
Particle Accelerators ◽  
Carbon Ions ◽  
Particle Beams ◽  
Radiation Fields ◽  
Number Of Particles

In this paper after mentioning the clinical radiation fields of 20 keV-450 MeV/u, they are characterized by the number of particles and their energy. Particle energy is the quantity that determines radiation penetration at the depth at which the tumor is situated (Fig. 1). The number of particles (or beam intensity) is the second major quantity that assures the administration of the absorbed dose in the tumor. The first application shows the radiation levels planned for various radiation fields. Prior to interacting with the medium, the intensity (or energy fluence rate) allows the determination of energy density, energy, power and relativistic force. In the interaction process, it determines the absorbed dose, kerma and exposure. Non-ionizing radiations in the EM spectrum are used as negative energy waves to accelerate particles charged into special installations called particle accelerators. The particles extracted from the accelerator are the source of the corpuscular radiation for high-energy radiotherapy. Of these, light particle beams (electrons and photons) for radiotherapy are generated by betatron, linac, microtron, and synchrotron and heavy particle beams (protons and heavy ions) are generated by cyclotron, isochronous cyclotron, synchro-cyclotron and synchrotron. The ionization dosimetry method used is the ionization chamber for both indirectly ionizing radiation (photons and neutrons) and for directly ionizing radiation (electrons, protons and carbon ions). Because the necessary energies for hadrons therapy are relatively high, 50-250 MeV for protons and 100-450 MeV/u for carbon ions, the alternative to replace non-ionizing radiation with relativistic laser radiation for generating clinical corpuscular radiation through radiation pressure acceleration mechanism (RPA) is presented.

scholarly journals Constraints on the optical-IR extragalactic background from γ-ray absorption studies

2011 ◽  
Vol 7 (S284) ◽  
pp. 420-428 ◽  
Author(s):  
Luigi Costamante
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Background Light ◽  
Radiation Fields ◽  
Direct Measurements ◽  
Absorption Studies ◽  
Diffuse Background ◽  
Very High Energy ◽  
Tev Gamma Rays ◽  
Very High

AbstractVery high energy (VHE ≳0.1 TeV) gamma-rays from extragalactic sources, interacting by γ-γ collisions with diffuse intergalactic radiation fields, provide an alternative way to constrain the diffuse background light, completely independent of direct measurements. The limits depend however on our knowledge of the physics of the gamma-ray sources. After clarifying the interplay between background light and VHE spectra, I summarize the extent and validity of the obtainable limits, and where future improvements can be expected.

Equivalent dose measurements in high-energy radiation fields with Rossi counters

1979 ◽  
Vol 22 (7) ◽  
pp. 862-864
Author(s):  
V. I. Glazkov ◽  
Yu. E. Makovskii ◽  
I. V. Filyushkin
Keyword(s):  
High Energy ◽  
Equivalent Dose ◽  
High Energy Radiation ◽  
Energy Radiation ◽  
Radiation Fields ◽  
Dose Measurements

scholarly journals Comparison of Dosimetry Protocols for Electron Beam Radiotherapy Calibrations and Measurement Uncertainties

Life ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Fawzia E. M. Elbashir ◽  
Wassim Ksouri ◽  
Mohamed Hassan Eisa ◽  
Sitah Alanazi ◽  
Farouk Habbani ◽  
...  
Keyword(s):  
Electron Beam ◽  
Reference Conditions ◽  
Absorbed Dose ◽  
High Energy ◽  
Energy Agency ◽  
Plane Parallel ◽  
Reference Quality ◽  
Electron Beam Radiotherapy ◽  
Dose Measurements ◽  
High Degree

This paper presents guidelines for the calibration of radiation beams that were issued by the International Atomic Energy Agency (IAEA TRS 398), the American Association of Physicists in Medicine (AAPM TG 51) and the German task group (DIN 6800-2). These protocols are based on the use of an ionization chamber calibrated in terms of absorbed dose to water in a standard laboratory’s reference quality beam, where the previous protocols were based on air kerma standards. This study aims to determine uncertainties in dosimetry for electron beam radiotherapy using internationally established high-energy radiotherapy beam calibration standards. Methods: Dw was determined in 6-, 12- and 18 MeV electron energies under reference conditions using three cylindrical and two plane-parallel ion chambers in concert with the IAEA TRS 398, AAPM TG 51 and DIN 6800-2 absorbed dose protocols. From mean measured Dw values, the ratio TRS 398/TG 51 was found to vary between 0.988 and 1.004, while for the counterpart TRS 398/DIN 6800-2 and TG 51/DIN 6800-2, the variation ranges were 0.991–1.003 and 0.997–1.005, respectively. For the cylindrical chambers, the relative combined uncertainty (k = 1) in absorbed dose measurements was 1.44%, while for the plane-parallel chambers, it ranged from 1.53 to 1.88%. Conclusions: A high degree of consistency was demonstrated among the three protocols. It is suggested that in the use of the presently determined dose conversion factors across the three protocols, dose intercomparisons can be facilitated between radiotherapy centres.

Dosimetry of High-Energy Photon Beams Based on Standards of Absorbed Dose to Water: Abstract

2001 ◽  
Vol 1 (1) ◽  
pp. 8-8 ◽  
Author(s):  
K. Hohlfeld ◽  
P. Andreo ◽  
O. Mattsson ◽  
J. P. Simoen
Keyword(s):  
Reference Conditions ◽  
International Comparisons ◽  
Absorbed Dose ◽  
High Energy ◽  
National Standards ◽  
Photon Radiation ◽  
Photon Beams ◽  
Radiation Induced ◽  
Absorbed Dose To Water ◽  
Primary Standards

This report examines the methods by which absorbed dose to water can be determined for photon radiations with maximum energies from approximately 1 MeV to 50 MeV, the beam qualities most commonly used for radiation therapy. The report is primarily concerned with methods of measurement for photon radiation, but many aspects are also relevant to the dosimetry of other therapeutic beams (high-energy electrons, protons, etc.). It deals with methods that are sufficiently precise and well established to be incorporated into the dosimetric measurement chain as primary standards (i.e., methods based on ionisation, radiation-induced chemical changes, and calorimetry using either graphite or water). The report discusses the primary dose standards used in several national standards laboratories and reviews the international comparisons that have been made. The report also describes the reference conditions that are suitable for establishing primary standards and provides a formalism for determining absorbed dose, including a discussion of correction factors needed under conditions other than those used to calibrate an instrument at the standards laboratory.

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