Experimental study of the Ho(d, 2n) and Ho(d, p) nuclear reactions up to 20 MeV for production of the therapeutic radioisotopes Er and Ho

The radioisotope ¹⁶⁵Er (T_1/2 = 10.36 h) is a candidate for Auger-electron therapy. The β⁻-emitting ^166gHo (T_1/2 = 26.83 h) is now being explored for various therapeutic applications. In the frame of our systematic study of charged particle production routes of therapeutic radionuclides the excitation functions of the ¹⁶⁵Ho(d, 2n)¹⁶⁵Er and ¹⁶⁵Ho(d, p)^166gHo reactions were measured up to 20 MeV by using a stacked foil irradiation technique and X/γ-ray spectroscopy. The excitation function of the ¹⁶⁵Ho(d, 2n)¹⁶⁵Er reaction was measured for the first time while for the ¹⁶⁵Ho(d, p)^166gHo reaction only a single dataset of earlier measured cross-sections was found. The measured excitation functions were compared to the results of different nuclear reaction model codes. The calculated thick target yield of the ¹⁶⁵Ho(d, 2n) reaction is significantly higher over the optimal energy range than that for the ¹⁶⁵Ho(p, n) reaction investigated earlier by us. The integral yield of the ¹⁶⁵Ho(d, p)^166gHo reaction is rather low compared to the established ¹⁶⁵Ho(n, γ)¹⁶⁶Ho reaction in a nuclear reactor.     

Excitation functions of proton induced nuclear reactions on W up to 40 MeV

We measured the excitation functions for the production of the ^{181,182m,182g,183,184g,186}Re radioisotopes from proton bombardment of natural tungsten by using a stacked-foil activation technique in the energy range from threshold energy to 40 MeV at the MC50 cyclotron of the Korea Institute of Radiological and Medical Science. The results were compared with the earlier reported experimental data and the model calculations using codes TALYS and ALICE-IPPE. The present values are in good agreement with some of the previously reported literature. The integral yields for thick targets were also deduced from the measured excitation functions of the produced radioisotopes. The deduced yield values were compared with the available directly measured thick target yield, and found acceptable agreement. The investigated radioisotope ¹⁸⁶Re has remarkable applications in the field of nuclear medicine, whereas the data of ^183,184gRe have potential applications in thin layer activation analysis.     

Evaluated activation cross sections of longer-lived radionuclides produced by deuteron induced reactions on natural iron up to 10 MeV

Charged particle induced reactions can be used to monitor in real time the wear of mechanical structures such as internal combustion engines and turbines. Charged particle induced reactions with suitable properties also can be used for monitoring the actual parameters of bombarding particle beams. One of these reactions is the ^natFe(d,x)⁵⁷Co process. The available experimental data in the literature are well established around and above the maximum of the excitation function, however only a little, scattered data are available in the threshold energy region of the reaction. In this work we measured the excitation functions of relevant processes resulting in ^55,56,57,58Co, ⁵⁹Fe and ^52,54Mn induced by deuteron beams on natural iron in the energy range from threshold up to 10 MeV. The new experimental data collected are used to determine with high confidence recommended values for the missing low energy part of the investigated excitation functions.     

Production cross-sections of residual radionuclides from proton-induced reactions on Ag up to 40 MeV

We measured the cross-sections of the ^{104g,105,106m}Ag and ^104,107Cd radionuclides produced by proton-induced reactions on natural silver by using a stacked-foil activation technique in the energy range from a threshold energy to 40 MeV at a MC50 cyclotron. The results showed generally good agreement with available data as well as the theoretical data. The integral yields for thick targets were also deduced using the measured cross-sections and the stopping power of ^natAg over the energy range from a threshold energy to 40 MeV, taking into account that the total energy is absorbed in the targets. The production cross-sections for the ^104gAg and the ¹⁰⁴Cd radionuclides from natural silver were measured for the first time.     

A detailed study of the d + B system for nuclear reaction analysis - Part A: The B(d,p)B reaction in the energy region Ed,lab = 900-2000 keV

The differential cross-sections of the ¹⁰B(d,p_{0,1,2,3,4-5,6}) reactions for the determination of the depth distribution of boron in near-surface layers of materials have been determined in the projectile energy region E_d,lab = 900-2000 keV. The experiment was carried out in energy steps of 25 keV and for eight detector angles between 135° and 170° (in steps of 5°). The obtained experimental data are suitable for nuclear reaction analysis (NRA) studies. A qualitative discussion of the observed cross-section variations through the strong influence of overlapping resonances in the d + ¹⁰B system is also presented.     

Measurement of cross-sections for the (p, xn) reactions in natural molybdenum

Cross-sections for the residual radionuclide productions by proton-induced activation on natural molybdenum were measured up to 40 MeV by using a stacked-foil technique at the MC50 cyclotron of the Korea Institute of Radiological and Medical Sciences (KIRAMS). This work has given a new data set for the formation of the investigated radionuclides. The present results for most of the radionuclides showed in general good agreement with the earlier reported data as well as the theoretical data taken from the calculations based on the ALICE-IPPE code. The integral yields for thick targets were also deduced from the measured cross-sections of the produced radionuclides. The optimum production of the ^99mTc radionuclide with minimum impurities can be obtained at the energy ranges from 10 to 23 MeV, where the production yields were obtained as 597.15 MBqμA⁻¹h⁻¹ at saturation. The measured cross-sections are used for production of medically important radionuclides such as ^99mTc, ^94mTc and ^93m,gTc by using the medium-energy cyclotrons.     

Excitation functions of the proton-induced nuclear reactions on Sn up to 40 MeV

We have measured the production cross-sections of the residual radionuclides for proton-induced reactions on natural tin by using a stacked-foil activation technique in the energy range from threshold energy to 40 MeV at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the earlier reported experimental data and theoretical calculations based on the TALYS and the ALICE-IPPE codes. The present results are in general good agreement with the available literature data and calculated results by using the computer codes TALYS and ALICE-IPPE. The thick target integral yields were also deduced from the measured excitation functions of the produced radionuclides.     

Study of the excitation functions for K, Sc and Ti by proton irradiation on Sc up to 37 MeV

The excitation functions of proton induced reactions on Sc targets (100% ⁴⁵Sc), leading to the formation isotopes ⁴³K, ⁴³Sc, ^44mSc, ^44gSc and ⁴⁴Ti were studied by the stacked foil activation technique up to 37 MeV. High-resolution gamma-spectrometry measurements were performed on an HPGe detector in order to determine the activity of the irradiated Sc₂O₃ pellets and Ti monitor foils. The reaction cross-sections were measured from their respective thresholds up to E_p = 36.4 MeV and were compared with previous values reported in literature. Possible batch yields and optimal irradiation parameters for generator ⁴⁴Ti -^44gSc in high current accelerators are discussed.     

Calculation and evaluation of cross-sections for p+Fe reactions up to 250 MeV

All cross-sections of proton-induced reactions, angular distributions and the energy spectra of neutron, proton, deuteron, triton, helium and alpha-particle emission are consistent calculated and analyzed for p+^{54,56,57,58,nat}Fe at incident proton energies below 250 MeV by using nuclear theoretical models which integrate the optical model, the intra-nuclear cascade model, direct, preequilibrium and equilibrium reaction theories. Especially, the cross-sections of the light composite particle (d, t, ³He and α) emissions are improved based on the exciton model including the pick-up mechanism. Theoretical calculated results are compared with existing experimental data.     

The (He, tf) as a surrogate reaction to determine (n, f) cross sections in the 10-20 MeV energy range

The surrogate reaction ²³⁸U(³He, tf) is used to determine the ²³⁷Np(n, f) cross section indirectly over an equivalent neutron energy range from 10 to 20 MeV. A self-supporting ∼761 μg/cm² metallic ²³⁸U foil was bombarded with a 42 MeV ³He²⁺ beam from the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Outgoing charged particles and fission fragments were identified using the Silicon Telescope Array for Reaction Studies (STARS) consisted of two 140 μm and one 1000 μm Micron S2 type silicon detectors. The ²³⁷Np(n, f) cross sections, determined indirectly, were compared with the ²³⁷Np(n, f) cross section data from direct measurements, the Evaluated Nuclear Data File (ENDF/B-VII.0), and the Japanese Evaluated Nuclear Data Library (JENDL 3.3) and found to closely follow those datasets. Use of the (³He, tf) reaction as a surrogate to extract (n, f) cross sections in the 10-20 MeV equivalent neutron energy range is found to be suitable.     

Differential cross section measurements of the S(d,p)S reaction for nuclear reaction analysis purposes

Differential cross sections of the ³²S(d,p_{0,1,2,3,4-6,7}) reactions were determined for deuteron energies E_lab = 1975-2600 keV (in steps of 25 keV) and for detector angles between 140-170° in steps of 10°. A comparison of the experimental data with the existing ones and possible applications to nuclear reaction analysis (NRA) studies are discussed.     

Evaluated activation cross sections of longer-lived radionuclides produced by deuteron induced reactions on natural titanium

Selected charged particle induced reactions are used to monitor the actual parameters of bombarding particle beams. One of these reactions is ^natTi(d, x)⁴⁸V for which recommended cross section data are available in one of the databases of the International Atomic Energy Agency (http://www-nds.iaea.or.at/medical/). This database contains all together 22 monitor reactions for practical applications covering energy up to 100 MeV depending on the reactions. In the case of the ^natTi(d, x)⁴⁸V reaction recommended data are given in the 9-50 MeV energy interval because at the time of creation not precise enough experimental data were available to recommend values from threshold up to 9 MeV. In this work we measured the excitation function in this relevant low energy range, collected new experimental data and suggest high confidence recommended values for the missing low energy part of the monitor excitation function.     

Production cross-sections for the residual radionuclides from the Cd(p, x) nuclear processes

We measured the production cross-sections of the ^{107,111m,115g}Cd, ^{108m,108g,109g,110m,110,111g,113m,114m,115m,116m}In and ^{104g,105g,106m,110m,111g,113g}Ag radionuclides for proton-induced reactions on cadmium by using a stacked-foil activation technique in the energy rangy between 3 and 40 MeV at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Science. The measured cross-sections were compared with the available literature data and the theoretical calculations by the model codes TALYS and ALICE-IPPE. The integral yields for thick targets were also obtained from the measured cross-sections of the produced radionuclides. The measured cross-sections, especially the indium (In) radionuclides have a significance for various practical applications; thin layer activation analysis, nuclear medicine, nuclear technology, radioactive waste handling, etc.     

Measurement of thick target yields of the S(α,x)Cl nuclear reaction and estimation of its excitation function up to 70 MeV

Thick target yields of the ^natS(α,x)^34mCl nuclear reaction were measured in the energy region from 14.2 to 69.5 MeV. Our results were also compared to the only available literature dataset. Cross-sections of the above reaction were also estimated from the obtained thick target yields. Pure natural sulfur used as a target material resulted in a thick target saturation yield of 1557 ± 18 MBq (42.1 ± 0.5 mCi)/μA at 69.5 MeV. The estimated excitation function curve of the ^natS(α,x)^34mCl process showed a maximum cross-section of 122 mbarn at about 27.5 MeV.     

Differential cross-section measurements for the C(d, p0)C reaction and applications to surface analysis of materials

This work involves surface analysis by nuclear techniques, which are non-destructive, and computer simulation. The “energy analysis” method for nuclear reaction analysis is used. Energy spectra are computer simulated and compared to experimental data, giving target composition and concentration profile information. Measured values are presented for the differential cross-section of the ¹²C(d, p₀)¹³C reaction in the deuteron energy range 0.81-2.07 MeV for laboratory detection angles of 165° and 135°, using self-supported two-layered targets consisting of high purity thin films of typically 13 μg/cm² natural carbon and 65 μg/cm² gold. The error in the absolute differential cross-section values is generally ∼6%. The method, using these values, is successfully applied to determination of uniform concentration profiles of ¹²C, along considerable depths, for a thick flat target of high purity pyrolitic graphite. It is characterised a thin surface film of carbon on a thick flat quartz target. Uniform concentration profiles of ¹⁶O are also obtained from (d, p) and (d, α) reactions.     

Alpha induced reactions on Cd and Cd: An experimental study of excitation functions

Excitation functions of alpha induced reactions on enriched ¹¹⁴Cd and ¹¹⁶Cd targets, leading to the formation of the ^117m,119mSn, ^{114m₁,115m,116m,117m,g}In, ^115gCd isotopes, were studied by the stacked foil activation technique. Reaction cross-sections were measured from their respective thresholds up to E_α = 38.9 MeV. Quantification of induced isotopes has been made by gamma and X-ray spectrometry. The experimental cross-sections are compared, where available, with values reported previously in literature. Thick target yield for the medically important radionuclide ^117mSn is calculated based on discrete values of measured cross-sections.     

Measurement of (d,p) and (d,α) differential cross-sections for N

The differential cross-sections for ¹⁴N(d,p₀)¹⁵N, ¹⁴N(d,p₁₊₂)¹⁵N, ¹⁴N(d,α₀)¹²C and ¹⁴N(d,α₁)¹²C have been measured in the energy range from 0.7 to 2.2 MeV at the laboratory angle of 150°. The obtained results are compared with data published in the literature. Discrepancies between new and previously acquired data are discussed. The cross-sections measured in the present work were uploaded to the IBANDL data base <http://www-nds.iaea.org/ibandl/>.     

Excitation functions for some W, Ta and Hf radionuclides obtained by deuteron irradiation of Ta up to 40 MeV

Experimental excitation functions for deuteron induced reactions up to 40 MeV on mono-isotopic Ta (¹⁸¹Ta) were measured with the activation method using a stacked foil irradiation technique. From high resolution gamma spectrometry and X-ray analysis cross-section data for the production of ¹⁸¹W, ^{177,178g,180g,182m+g}Ta, and ^179m2,180mHf were determined. Comparison with the scarce earlier published data are presented and results for values predicted by different theoretical codes, adapted for more reliable calculations for d-induced reactions, are included. Thick target yields for ^{182m+g,180g,178g}Ta and ¹⁸¹W were calculated from a fit to our experimental excitation curves. Using dose conversion factors and irradiation scenarios, possible occupational doses to maintenance or scientific personnel around high power accelerators where Ta based structural elements (collimators, beam stoppers, shielding) are present could be derived.