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The production of brachytherapy radio-nuclide 169Yb was investigated in the 169Tm(p,n), 170Yb(p,2n), 171Yb(p,3n), 172Yb(p,4n), 169Tm(d,2n), 168Er(α,3n), 167Er(α,2n) and 166Er(α,n) reactions. The cross section of these reactions were calculated using TALYS 1.9 code and compared with the available experimental results. SRIM-2013 code and GEANT4 toolkit were used to calculate the stopping power, range and projectile flux within the target. The optimum target thickness, theoretical and simulation production yield of 169Yb radioisotope in each reaction were calculated. Finally, the 169Tm(p, n) reaction with high production yield was suggested to produce 169Yb radioisotope.

Lead and zinc ores are the most important natural raw materials widely used in the industry. These types of ores contain different amounts of radionuclides that expose workers to radiation during extraction, transport, and processing. In this study, 22 samples were collected, including 18 samples of lead–zinc ore and 4 samples of mining waste. Specific activities of 226Ra, 232Th, and 40K were determined using a high-purity germanium gamma radiation detector (HPGe). The specific activities of corresponding radionuclides in lead–zinc ore samples varied in the range (

In the present study, the theoretical estimation of a combined production of

We measured the excitation functions of natTa(p,x)177,178W, natTa(p,x)176,177,178m1,180gTa, and natTa(p,x)175,179m2,180mHf reactions up to the proton energy of 44.2 MeV using the stacked-foil activation technique. The measured results were compared with the literature data as well as with the theoretical values obtained from the TENDL-2017 library based on the TALYS-1.9 code. The integral yields for thick target of the investigated radionuclides were determined from the measured excitation functions. The purpose was to provide a new data set for the formation of the investigated radionuclides applicable in medicine and industry and to provide information that could support in testing and understanding the nuclear reaction theories.

The flux-weighted average cross sections of the 89Y(γ,xn; x=1–4)89−x Y reactions and the isomeric yield ratios of the 87m,gY, 86m,gY, and 85m,gY radionuclides produced in these reactions with the bremsstrahlung end-point energies of 65, 70 and 75 MeV have been determined by an activation and off-line γ-ray spectrometric technique using the 100 MeV electron linac in Pohang Accelerator Laboratory, Korea. The theoretical 89Y(γ,xn; x=1–4)89−x Y reactioncross sections for mono-energetic photonshave been calculated using the computer code TALYS 1.6. Then the flux-weighted theoretical values were obtaind to compare with the present data. The flux-weighted experimental and theoretical 89Y(γ,xn; x=1–4)89−x Y reaction cross sections increase very fast from the threshold values to a certain bremsstrahlung energy, wherethe other reaction channels open up. Thereafter it remains constant a while and then slowly decreases with the increase of cross sections for other reactions. Similarly, the isomeric yield ratios of 87m,gY,86m,gY and 85m,gY in the 89Y(γ,xn; x=2–4)89−x Y reactions from the present work and literature data show an increasing trend from their respective threshold values to a certain bremsstrahlung energy. After a certain point ofenergy, the isomeric yield ratios increase slowly with the bremsstrahlung energy. These observations indicate the role of excitation energy and its partitioning in different reaction channels.

Aim The aim of this study is simulation of the proton depth-dose distribution and dose evaluation of secondary particles in proton therapy of brain tumor using the GEANT4 and FLUKA Monte Carlo codes. Background Proton therapy is a treatment method for variety of tumors such as brain tumor. The most important feature of high energy proton beams is the energy deposition as a Bragg curve and the possibility of creating the spread out Bragg peak (SOBP) for full coverage of the tumor. Materials and methods A spherical tumor with the radius of 1 cm in the brain is considered. A SNYDER head phantom has been irradiated with 30−130 MeV proton beam energy. A PMMA modulator wheel is used for covering the tumor. The simulations are performed using the GEANT4 and FLUKA codes. Results Using a modulator wheel, the Spread Out Bragg Peak longitudinally and laterally covers the tumor. Flux and absorbed dose of secondary particles produced by nuclear interactions of protons with elements in the head are considerably small compared to protons. Conclusions Using 76.85 MeV proton beam and a modulator wheel, the tumor can be treated accurately in the 3-D, so that the distribution of proton dose in the surrounding tissues is very low. The results show that more than 99% of the total dose of secondary particles and protons is absorbed in the tumor.

The flux weighted average cross sections and the isomeric yield ratios of 110m, gIn, 111m, gIn and 112m, gIn in the natIn( $\gamma$ ,xn) 112-110In reactions with the bremsstrahlung end-point energies of 65, 70 and 75 MeV have been determined by activation and off-line $\gamma$ -ray spectrometric technique using the 100 MeV electron linac at Pohang accelerator laboratory, Korea. It was found that the natIn( $\gamma$ ,xn) 112-110In reaction cross sections increase very fast from the threshold energy to a certain value of the bremsstrahlung energy, where the other reaction channel opens. After a certain energy, it remains constant because the cross section of the other reaction channel starts to increase. This indicates the partition of the excitation energy in different reaction channles. The isomeric yield ratios of 110m, gIn, 111m, gIn and 112m, gIn in the natIn( $\gamma$ ,xn) reactions decrease very fast with the bemsstrahlung end-point energy from the threshold value to 15-30 MeV due to the giant dipole resonance (GDR) effect. Above that, the isomeric yield ratios increase slowly with the bremsstrahlung energy due to the increase of excitation energy.

The excitation functions of 93mMo and 91m,92m,95m,gNb produced from alpha-induced reactions on 93Nb were measured from their respective threshold to 39.5 MeV. The study was conducted using the alpha beam from the Variable Energy Cyclotron Centre (VECC), Kolkata, India, the stacked foil activation technique and the off-line gamma ray spectrometric technique. The integral yields for a thick target were also deduced from the measured cross-sections and the stopping power of niobium. The results were compared with earlier reported data as well as with the theoretical values obtained from the TENDL-2013 library based on the TALYS-1.6 code.

The isomeric yield ratios of 86m,gY, 87m,gY, and 89m,gZr produced in the reactions of 89Y and natZr with end-point bremsstrahlung energies of 45 and 55 MeV have been determined by activation and off-line γ-ray spectrometric technique using the 100 MeV electron linac at Pohang Accelerator Laboratory (PAL), Korea. The present data along with literature data show that the isomeric yield ratios of 86m,gY and 87m,gY in the 89Y(γ,xn) and natZr(γ,x) reactions and those of 89m,gZr in the natZr(γ,x) reaction increase with the end-point bremsstrahlung energy, which indicates the effect of excitation energy. However, the increase trend of the isomeric yield ratios of 87m,gY in the 89Y(γ,xn) reaction and 89m,gZr in the natZr(γ,x) reaction are very fast from the threshold value to 30 MeV due to the giant dipole resonance effect. After certain point of excitation energy, the isomeric yield ratios increase slowly with the end-point bremsstrahlung energy due to the partition of energy in different reaction channels. It was also observed that in both the reactions, the isomeric yield ratios of 87m,gY are always higher than those of 86m,gY. This is because of more number of particle emission and thus the disposition of more excitation energy needed for the formation of 86m,gY compared to 87m,gY.

The isomeric yield ratios for the natAg(γ,xn)104m,g,106m,gAg reactions with the end-point bremsstrahlung energies of 45- and 55-MeV have been determined by the off-line γ-ray spectrometric technique using 100 MeV electron linac at Pohang accelerator laboratory, Korea. The present data were compared with literature data in comparable compound nucleus from the natAg(γ,xn), natPd(p,xn), and 103Rh(α,xn) reactions to examine the effects of an excitation energy and an input angular momentum. It is observed that the isomeric yield ratios of 104,106Ag in natAg(γ,xn), natPd(p,xn) and 103Rh(α,xn) reactions increase with the end-point bremsstrahlung energy, proton and alpha energy, which indicate the role of excitation energy. It is also found that for the similar compound nucleus at same excitation energy, the isomeric yield ratio of 104m,gAg is higher in the natPd(p,xn) and 103Rh(α,xn) reactions than those in natAg(γ,xn) reaction, which indicate the effect of an input angular momentum.

The cross-sections for 89Y(γ, n)88Y, 89Y(γ, 2n)87Y, 89Y(γ, 3n)86Y, and 89Y(γ, 4n)85Y reactions in the end-point bremsstrahlung energies of 45 and 55 MeV have been determined for the first time by an activation and an off-line γ-ray spectrometric techniques using the electron linear accelerator in Pohang accelerator laboratory. The photon-induced reaction cross-sections of 89Y as a function of photon energy were calculated using the TALYS 1.4. The flux-weighted average cross-sections were obtained from the existing experimental data and the theoretical values of the TALYS 1.4 with the mono-energetic photons. The present results for 89Y(γ, xn; x = 1–4) reactions are compared with the flux-weighted average values from the literature and those from the TALYS 1.4. It was shown that the 89Y(γ, xn, x = 1–4) reaction cross-sections increase sharply from their threshold values to certain energies, where other reaction channels opens. Then it remains constant a while, where the next reaction channel increases. There after it decrease slowly with increase of bremsstrahlung energy due to opening of different reaction channels.

The photo-neutron cross-sections of 93Nb at the end-point bremsstrahlung energies of 12, 14 and 16 MeV as well as 45, 50, 55, 60 and 70 MeV have been determined by the activation and the off-line γ-ray spectrometric techniques using the 20 MeV electron linac (ELBE) at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and 100 MeV electron linac at Pohang Accelerator Laboratory (PAL), Pohang, Korea. The 93Nb(γ, xn, x = 1 – 4 ) reaction cross-sections as a function of photon energy were also calculated using computer code TALYS 1.4. The flux-weighted average values were obtained from the experimental and the theoretical (TALYS) values based on mono-energetic photons. The experimental values of present work are in good agreement with the flux-weighted theoretical values of TALYS 1.4 but are slightly higher than the flux-weighted experimental data of mono-energetic photons. It was also found that the theoretical and the experimental values of present work and literature data for the 93Nb(γ, xn) reaction cross-sections increase from the threshold values to a certain energy, where other reaction channels opens. However, the increase of 93Nb(γ, n) and 93Nb(γ, 2n) reaction cross-sections are sharper compared to 93Nb(γ, 3n) and 93Nb(γ, 4n) reaction cross-sections. The sharp increase of 93Nb(γ, n) and 93Nb(γ, 2n) reaction cross-sections from the threshold value up to 17–22 MeV is due to the Giant Dipole Resonance (GDR) effect besides the role of excitation energy. After a certain values, the individual 93Nb(γ, xn) reaction cross-sections decrease with increase of bremsstrahlung energy due to opening of other reaction channels.