scholarly journals ON CRITICAL PARAMETERS OF PHOTONUCLEAR ISOTOPE PRODUCTION

2019 ◽  
pp. 153-157
Author(s):  
V.L. Uvarov
Keyword(s):  
Experimental Study ◽  
Specific Activity ◽  
Thin Foil ◽  
High Energy ◽  
Critical Parameters ◽  
Photon Flux ◽  
Isotope Production ◽  
Bremsstrahlung Radiation ◽  
Production Target ◽  
Product Isotope

Analytical model for description of isotope generation in a thick production target exposed to no uniform flux of high-energy bremsstrahlung radiation is developed. A set of principal process parameters determinative the yield of a product isotope and distribution of its specific activity has been established. It is shown, that as those parameters may be the yield of the product isotope in a thin foil overlapping the photon flux, normalized to the mass thickness of the foil (a coefficient of photonuclear conversion), and also the standard radial deviation of the flux density of the above-threshold photons at the target as well as the most probable angle of their escape from a bremsstrahlung converter. The methods for measuring those parameters are proposed. Testing of the model was conducted using the 100Мо(g,n)99Mo reaction by comparing the results obtained from the model consideration with the data of experimental study and computer simulation. The proposed approach enables the optimization of photonuclear technology as respects to target dimensions and activation regime.

scholarly journals AN ESTIMATE OF 47Sc PHOTONUCLEAR YIELD IN A PRODUCTION TARGET

2020 ◽  
pp. 158-162
Author(s):  
N.P. Dikiy ◽  
Yu.V. Lyashko ◽  
V.A. Shevchenko ◽  
A.Eh. Tenishev ◽  
V.L. Uvarov ◽  
...  
Keyword(s):  
Cross Section ◽  
Specific Activity ◽  
Optimal Size ◽  
Activation Technique ◽  
Isotope Production ◽  
Bremsstrahlung Radiation ◽  
Thin Foils ◽  
Foil Activation ◽  
Carrier Free ◽  
Production Target

47Sc is considered as a promising beta-emitter for cancer immunotherapy. For its carrier-free production, the 48Ti(γ,p)47Sc reaction in the field of bremsstrahlung radiation of an electron accelerator can be used. On the basis of developed analytical model and a double-foil activation technique, the main characteristics of the photonuclear isotope production and optimal dimensions of a production target have been established. The measured photonuclear yield of 47Sc and dominant scandium admixtures in thin foils of natural titanium in the electron energy range of 35 to 95 MeV enabled to specify the available data on the cross-section of the48Ti(γ,p)47Sc reaction. Using those results, the gross and specific activity of 47Sc in the cylindrical titanium targets of optimal size were calculated by a simulation technique. The comparison of capacity of the photonuclear method of the 47Sc production with other techniques is carried out.

Neutron dose evaluation of Elekta Linac at two energies (10 & 18 MV) by MCNP code and comparison with experimental measurements

2014 ◽  
Vol 6 (1) ◽  
pp. 1006-1015
Author(s):  
Negin Shagholi ◽  
Hassan Ali ◽  
Mahdi Sadeghi ◽  
Arjang Shahvar ◽  
Hoda Darestani ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Measurement Data ◽  
Calculated Data ◽  
High Energy ◽  
Neutron Dose ◽  
Dose Assessment ◽  
Photon Flux ◽  
Dose Equivalent ◽  
Monte Carlo Techniques ◽  
Neutron Dose Equivalent

Medical linear accelerators, besides the clinically high energy electron and photon beams, produce other secondary particles such as neutrons which escalate the delivered dose. In this study the neutron dose at 10 and 18MV Elekta linac was obtained by using TLD600 and TLD700 as well as Monte Carlo simulation. For neutron dose assessment in 2020 cm2 field, TLDs were calibrated at first. Gamma calibration was performed with 10 and 18 MV linac and neutron calibration was done with 241Am-Be neutron source. For simulation, MCNPX code was used then calculated neutron dose equivalent was compared with measurement data. Neutron dose equivalent at 18 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 3.3, 4, 5 and 6 cm. Neutron dose at depths of less than 3.3cm was zero and maximized at the depth of 4 cm (44.39 mSvGy-1), whereas calculation resulted  in the maximum of 2.32 mSvGy-1 at the same depth. Neutron dose at 10 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 2.5, 3.3, 4 and 5 cm. No photoneutron dose was observed at depths of less than 3.3cm and the maximum was at 4cm equal to 5.44mSvGy-1, however, the calculated data showed the maximum of 0.077mSvGy-1 at the same depth. The comparison between measured photo neutron dose and calculated data along the beam axis in different depths, shows that the measurement data were much more than the calculated data, so it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry in linac central axis due to high photon flux, whereas MCNPX Monte Carlo techniques still remain a valuable tool for photonuclear dose studies.

scholarly journals Green synthesis: Proposed mechanism and factors influencing the synthesis of platinum nanoparticles

2020 ◽  
Vol 9 (1) ◽  
pp. 386-398 ◽  
Author(s):  
Mahmood S. Jameel ◽  
Azlan Abdul Aziz ◽  
Mohammed Ali Dheyab
Keyword(s):  
Green Synthesis ◽  
Reaction Temperature ◽  
Platinum Nanoparticles ◽  
Energy Requirement ◽  
Average Particle Size ◽  
High Energy ◽  
Energy Utilization ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Average Particle

AbstractPlatinum nanoparticles (Pt NPs) have attracted interest in catalysis and biomedical applications due to their unique structural, optical, and catalytic properties. However, the conventional synthesis of Pt NPs using the chemical and physical methods is constrained by the use of harmful and costly chemicals, intricate preparation requirement, and high energy utilization. Hence, this review emphasizes on the green synthesis of Pt NPs using plant extracts as an alternative approach due to its simplicity, convenience, inexpensiveness, easy scalability, low energy requirement, environmental friendliness, and minimum usage of hazardous materials and maximized efficiency of the synthesis process. The underlying complex processes that cover the green synthesis (biosynthesis) of Pt NPs were reviewed. This review affirms the effects of different critical parameters (pH, reaction temperature, reaction time, and biomass dosage) on the size and shape of the synthesized Pt NPs. For instance, the average particle size of Pt NPs was reported to decrease with increasing pH, reaction temperature, and concentration of plant extract.

Experimental study of photon-electron conversion in copper during passage of high-energy bremsstrahlung

1969 ◽  
Vol 12 (6) ◽  
pp. 795-796
Author(s):  
V. A. Vorob'ev ◽  
S. A. Vorob'ev ◽  
A. V. Pushkin
Keyword(s):  
Experimental Study ◽  
High Energy ◽  
Electron Conversion

Experimental study on measuring pulse duration in the far field for high-energy petawatt lasers

2018 ◽  
Vol 57 (13) ◽  
pp. 3488
Author(s):  
Jianwei Yu ◽  
Xiaoping Ouyang ◽  
Li Zhou ◽  
Youen Jiang ◽  
Baoqiang Zhu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pulse Duration ◽  
High Energy ◽  
Far Field

High Energy Photon Flux Prediction from Neutralino Annihilation in the Globular Cluster Palomar 13

2006 ◽  
pp. 448-449
Author(s):  
Edmond Giraud ◽  
George Meylan ◽  
Mariusz Sapinski ◽  
Alain Falvard ◽  
Agnieszka Jacholkowska ◽  
...  
Keyword(s):  
Globular Cluster ◽  
High Energy ◽  
Photon Flux ◽  
High Energy Photon ◽  
Energy Photon

High-energy GARPUN KrF laser interaction with solid and thin-foil targets in ambient air

2004 ◽  
Author(s):  
Vladimir D. Zvorykin ◽  
Valerii G. Bakaev ◽  
Dimitri Batani ◽  
Ivan G. Lebo ◽  
A. O. Levchenko ◽  
...  
Keyword(s):  
Thin Foil ◽  
Ambient Air ◽  
High Energy ◽  
Laser Interaction ◽  
Krf Laser
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