Gamma-Rays From Electron, Proton Beam Interactions with Matter and/or Radiation: Application to Cyg X-1, Geminga and 3C 273

Protons of 7.1 Mev. energy from the MIT cyclotron have been used to investigate the angular distribution of gamma rays from the C12(p,p′γ) reaction with respect to the incoming proton beam. These gamma rays result from transitions between the first excited state of C12 at 4.45 Mev. and the ground state. The resulting distribution can be fitted by the expansion[Formula: see text]which is consistent with an assignment of two for the angular momentum of the first excited state of C12.

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INVESTIGATION OF PULSE SHAPE NEUTRON-GAMMA DISCRIMINATION

Resource-efficient Technologies ◽

10.18799/24056537/2019/3/247 ◽

2019 ◽

pp. 20-25

Author(s):

R.V. Avetisyan ◽

R.H. Avagyan ◽

A.E. Avetisyan ◽

A.V. Gyurjinyan ◽

A.G. Barseghyan ◽

...

Keyword(s):

Proton Beam ◽

Neutron Beam ◽

Gamma Rays ◽

Pulse Shape ◽

Gamma Ray ◽

Beam Current ◽

Pulse Shape Discrimination ◽

Physics Institute ◽

Neutron Beams ◽

Yerevan Physics Institute

The role of neutron beam investigation is significant not only for fundamental science but also for various fields of applied science. This work is dedicated to the formation of neutron beams using the external 18-MeV proton beam of IBA cyclotron C18/18 with a beam current of up to 100 µA. The facility is located at the A. Alikhanyan National Science Laboratory (Yerevan Physics Institute). The possibility to obtain thermal or epithermal neutron beams using the external proton beam of the cyclotron is studied using Geant4 simulations. In this case, a quasimonoenergetic neutron source 9Be (p, n)9B reaction is chosen. As a result of the simulations, the optimal thickness of the 9Be beryllium isotope target is determined. The induced neutron beam is accompanied by a gamma ray background. To decrease the number of accompanying gamma rays, the lead absorber is considered. As a method of separating neutrons from gamma rays, the pulse shape discrimination (PSD) technique is developed. This study shows the possibility of neutron-gamma PSD and its applicability using the EJ-299-33A plastic scintillator.

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Speedup Potential for Reconstruction Techniques for Prompt Gamma Imaging During Proton Radiotherapy

American Journal of Undergraduate Research ◽

10.33697/ajur.2018.004 ◽

2018 ◽

Vol 14 (4) ◽

Author(s):

James Della-Giustina ◽

Johnlemuel Casilag ◽

Elizabeth Gregorio ◽

Aniebiet Jacobs

Keyword(s):

Image Reconstruction ◽

Proton Beam ◽

Gamma Rays ◽

Radiation Treatment ◽

The Body ◽

Prompt Gamma ◽

Beam Radiation ◽

Gamma Imaging ◽

Proton Beam Radiation ◽

Prompt Gamma Imaging

Proton beam radiation treatment was first proposed by Robert Wilson in 1946. The advantage of proton beam radiation is that the lethal dose of radiation is delivered by a sharp increase toward the end of the beam range. This sharp increase, known as the Bragg peak, allows for the possibility of reducing the exposure of healthy tissue to radiation when comparing to x-ray radiation treatment. As the proton beam interacts with the molecules in the body, gamma rays are emitted. The origin of the gamma rays gives the location of the proton beam in the body, therefore, gamma ray imaging allows physicians to better take advantage of the benefits of proton beam radiation. These gamma rays are detected using a Compton Camera (CC) while the SOE algorithm is used to reconstruct images of these gamma rays as they are emitted from the patient. This imaging occurs while the radiation dose is delivered, which would allow the physician to make adjustments in real time in the treatment room, provided the image reconstruction is computed fast enough. This project focuses on speeding up the image reconstruction software with the use of parallel computing techniques involving MPI. Additionally, we demonstrate the use of the VTune performance analyzer to identify bottlenecks in a parallel code. KEYWORDS: Proton Beam Therapy; Image Reconstruction; SOE Algorithm; Parallel Computing; High Performance Computing; Medical Imaging; Prompt Gamma Imaging; Radiotherapy

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Mutagenic Effect of Proton Beams Characterized by Phenotypic Analysis and Whole Genome Sequencing in Arabidopsis

Frontiers in Plant Science ◽

10.3389/fpls.2021.752108 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sang Woo Lee ◽

Yu-Jeong Kwon ◽

Inwoo Baek ◽

Hong-Il Choi ◽

Joon-Woo Ahn ◽

...

Keyword(s):

Proton Beam ◽

Gamma Rays ◽

Gamma Ray ◽

Mutagenic Effect ◽

Mutation Rates ◽

Whole Genome ◽

Structural Variations ◽

Proton Beam Irradiation ◽

Proton Beams ◽

Gamma Ray Irradiation

Protons may have contributed to the evolution of plants as a major component of cosmic-rays and also have been used for mutagenesis in plants. Although the mutagenic effect of protons has been well-characterized in animals, no comprehensive phenotypic and genomic analyses has been reported in plants. Here, we investigated the phenotypes and whole genome sequences of Arabidopsis M2 lines derived by irradiation with proton beams and gamma-rays, to determine unique characteristics of proton beams in mutagenesis. We found that mutation frequency was dependent on the irradiation doses of both proton beams and gamma-rays. On the basis of the relationship between survival and mutation rates, we hypothesized that there may be a mutation rate threshold for survived individuals after irradiation. There were no significant differences between the total mutation rates in groups derived using proton beam or gamma-ray irradiation at doses that had similar impacts on survival rate. However, proton beam irradiation resulted in a broader mutant phenotype spectrum than gamma-ray irradiation, and proton beams generated more DNA structural variations (SVs) than gamma-rays. The most frequent SV was inversion. Most of the inversion junctions contained sequences with microhomology and were associated with the deletion of only a few nucleotides, which implies that preferential use of microhomology in non-homologous end joining was likely to be responsible for the SVs. These results show that protons, as particles with low linear energy transfer (LET), have unique characteristics in mutagenesis that partially overlap with those of low-LET gamma-rays and high-LET heavy ions in different respects.

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PRODUCTION OF HIGH-ENERGY GAMMA-RAYS BY PROTON BEAM AND THEIR MEASUREMENT.

Health Physics ◽

10.1097/00004032-200009000-00026 ◽

2000 ◽

pp. 311

Author(s):

&NA;

Keyword(s):

Proton Beam ◽

Gamma Rays ◽

High Energy ◽

High Energy Gamma ◽

Energy Gamma

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Comparative study of radio-sensitivity and relative biological effectiveness of gamma rays, x-rays, electron beam and proton beam in short grain aromatic rice

Indian Journal of Genetics and Plant Breeding (The) ◽

10.31742/ijgpb.80.4.3 ◽

2020 ◽

Vol 80 (04) ◽

Author(s):

Deepak Sharma ◽

Richa Sao ◽

Parmeshwar K. Sahu ◽

Gautam Vishwakarma ◽

J. P. Nair ◽

...

Keyword(s):

Electron Beam ◽

Proton Beam ◽

Gamma Rays ◽

Relative Biological Effectiveness ◽

Germination Percentage ◽

Mutation Breeding ◽

X Rays ◽

X Ray ◽

Biological Effectiveness ◽

Radio Sensitivity

Knowledge about the type of mutagen used and its optimized dose are of paramount importance to design and implement any plant mutation breeding programme. Present study was first time carried out to evaluate the comparative effectiveness, radio-sensitivity behavior and relative biological effectiveness of four physical mutagens viz., gamma rays, X-rays, electron beam and proton beam on two short grain aromatic rice landraces viz., Samundchini and Vishnubhog. The seeds of these two varieties were treated with 15 different doses of all four mutagens, ranging from 50Gy to 750Gy with an interval of 50Gy. Germination percentage and seedling growth parameters were recorded at seven and 15 days after sowing, respectively in two replications. It was observed that germination percentage, shoot and root length of the seedling gradually declined with the increase in doses of all the physical mutagens. On the basis of these observations, LD50 and GR50 doses were calculated. The present study reports the optimum range of doses for gamma ray (280 to 350 Gy); electron beam (290 to 330Gy); X-ray (200 to 250 Gy) and proton beam (150 to 200Gy). GR50 doses were observed higher than LD50 doses for all the mutagens in both landraces. However, Samundchini showed higher LD50 and GR50 doses than Vishnubhog indicating later to be more radio-sensitive. Furthermore, both the genotypes were highly radio-sensitive for proton beam and least for gamma rays. Similarly, high relative biological effectiveness was observed for proton beam followed by X-ray, electron beam and gamma rays indicating their decreasing trend of penetration capacity and lethality. Results of present study will be useful for plant breeders to use the above mutagens in an appropriate dose for mutation breeding in rice.

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