Excitation functions of natZn(p,x) nuclear reactions with proton beam energy below 18 MeV

We measured the excitation functions of ^natZn (p,x) reactions up to 17.6 MeV, using the stacked-foils activation technique. High-purity natural zinc (and copper) foils were irradiated with proton beams generated by an 18 MeV isochronous cyclotron. Activated foils were measured using high-purity Ge gamma spectroscopy to quantify the radionuclides ⁶¹Cu, ⁶⁶Ga, ⁶⁷Ga, and ⁶⁵Zn produced from the reactions. Thick-target integral yields were also deduced from the measured excitation functions of the produced radioisotopes. These results were compared with the published literature and were found to be in good agreement with most reports, particularly those most recently compiled.     

Activation cross-sections of proton induced reactions on natural Ni up to 65 MeV

Production cross-sections of the ^natNi(p,x)^60,61Cu, ^56,57Ni, ^55,56,57,58Co nuclear reactions were measured in five experiments up to 65 MeV by using a stacked foil activation technique. The results were compared with the available literature values, predictions of the nuclear reaction model codes ALICE-IPPE, TALYS-1.4, and extracted data from the TENDL-2012 library. Spline fits were made on the basis of selected data, from which physical yields were calculated and compared with the literature values. The applicability of the ^natNi(p,x)⁵⁷Ni, ⁵⁷Co reactions for thin layer activation (TLA) was investigated. The production rate for ⁵⁵Co was compared for proton and deuteron induced reactions on Ni.     

Excitation functions and yields for 111In production using 113, 114,natCd(p,xn)111In reactions with 65 MeV protons

Excitation function for the ¹¹³Cd(p,3n)¹¹¹In and ¹¹⁴Cd(p,4n)¹¹¹In reactions were measured by the stacked-foil technique in the energy range from 63 to 3 MeV. The results were compared with theoretical calculations based on the hydrid model using the well developed computer code ALICE. For the same energy range, the effective cross-sections were determined for the ^natCd(p,xn)¹¹¹In reactions. At the initial proton energy of 63 MeV for production of ¹¹¹In from ¹¹³Cd, ¹¹⁴Cd and ^natCd the cumulative yields were found as 16.7, 15.7 and 10.4 mCi/μ Ah respectively. The contamination of the undesired nuclide ^114mIn was determined. The no carrier added (NCA) ¹¹¹In was separated from the cadmium cyclotron-target by a procedure based on ion exchange chemistry. The radionuclidic purity of the final radioindium was determined.     

Activation cross sections for production of 7Be by proton and deuteron induced reactions on 9Be: Protons up to 65 MeV and deuterons up to 50 MeV

Experimental cross section data for the production of ⁷Be by ⁹Be(d,x)⁷Be reactions are presented for the first time at deuteron energies up to 50 MeV. For the ⁹Be(p,x)⁷Be reaction values up to 65 MeV are presented and compared to literature values. The cross sections were measured using an activation method in stacked foil irradiations followed by gamma-ray spectroscopy. Thick target yields were calculated and discussed in comparison with other ⁷Be producing reactions. The cross section data calculated with the latest versions of the TALYS code (TENDL2012 and TENDL2013 libraries) are discussed.     

Excitation functions of natGe(p,xn)71,72,73,74 As reactions up to 100 MeV with a focus on the production of 72 As for medical and 73 As for environmental studies.

Excitation functions for the formation of the arsenic radionuclides (71)As, (72)As, (73)As and (74)As in the interaction of protons with (nat)Ge were measured from the respective threshold energy up to 100 MeV. The conventional stacked-foil technique was used and the needed thin samples were prepared by sedimentation. Irradiations were done at three cyclotrons: CV 28 and injector of COSY at Forschungszentrum Jülich, and Separate Sector Cyclotron at iThemba LABS, Somerset West. The radioactivity was measured via high-resolution gamma-ray spectrometry. The measured cross section data were compared with the literature data as well as with the nuclear model calculations. In both cases, the results generally agree but there are discrepancies in some areas, the results of nuclear model calculation and some of the literature data being somewhat higher than our data. The integral yields of the four radionuclides were calculated from the measured excitation functions. The beta(+) emitting nuclide (72)As (T(1/2)=26.01 h) can be produced with reasonable radionuclidic purity ((71)As impurity: <10%) over the energy range E(p) = 18-->8 MeV; the yield of 93 MBq/microAh is, however, low. The radionuclide (73)As (T(1/2)=80.30 d), a potentially useful indicator in environmental studies, could be produced with good radionuclidic purity ((74)As impurity: <11%) over the energy range E(p) = 30 --> 18 MeV, provided, a decay time of about 60 days is allowed. Its yield would then correspond to 2.4 MBq/microAh, and GBq amounts could be produced when using a high current target.     

Excitation functions of 124Te(d,xn)124,125I reactions from threshold up to 14 MeV: comparative evaluation of nuclear routes for the production of 124I.

Excitation functions of the nuclear reactions 124Te(d,xn)124-125I were measured from their respective thresholds up to 14.0 MeV via the stacked-foil technique. Thin samples were prepared by electrolytic deposition of 99.8% enriched 124Te on Ti-backing. The excitation function of the 124Te(d,n)125I reaction was measured for the first time. The present data for the 124Te(d,2n)124I reaction are by an order of magnitude higher than the literature experimental data but are in good agreement with the results of a hybrid model calculation. From the measured cross sections, integral yields of 124,125I were calculated. The energy range Ed = 14 --> 10 MeV appears to be the best compromise between 124I-yield and 1251-impurity. The calculated 124I-yield amounts to 17.5 MBq/microA h and the 125I-impurity to 1.7%. A critical evaluation of the three nuclear routes for the production of 124I, viz. 124Te(d,2n)-, 124Te(p,n)- and 125Te(p,2n)-processes, is given. The reaction studied in this work proved to be least suitable. The 124Te(p,n)-reaction gives 124I of the highest radionuclidic purity, and a small-sized cyclotron is adequate for production purposes. The 125Te(p,2n)-reaction is more suitable at a medium-sized cyclotron: the yield of 124I is four times higher than in the other two reactions but the level of 0.9% 125I-impurity is relatively high.     

Experimental and theoretical excitation functions for Br(p,x) reactions

The excitation functions for protons incident on ^natBr were measured from threshold up to 100 MeV by means of the stacked-foil technique. Where applicable, the measured cross-section values are compared with previously published values. Theoretical cross-sections were also calculated by means of the computer code ALICE (IPPE) for comparison purposes.     

Cyclotron production of high-purity 123I I. A revision of excitation functions,thin-target and cumulative yields for 127I(p,xn) reactions

Excitation functions, thin-target and cumulative yields for the proton-induced reactions on ¹²⁷I targets were measured in the 67.5- to 5.3-MeV energy region. These results were used primarily to define the proton-energy ranges and target thicknesses to optimize radionuclide yields and purities for ¹²³I production from its 2.08-h ¹²³Xe parent. Other reactions producing radioxenons of interest in nuclear medicine (i.e. 36.406-d ¹²⁷Xe, 17.3-h ¹²⁵Xe, 20.1-h ¹²²Xe, and 38.85-min ¹²¹Xe), were also measured. These results are compared to other previously reported values.     

Excitation functions of (p,x) reactions on natural nickel between proton energies of 2.7 and 27.5 MeV.

Excitation functions have been measured for a number of proton induced nuclear reactions on natural nickel in the energy range from 27.5 MeV down to their threshold energy, using the activation method on stacked foils. Excitation functions for the reactions leading to the formation of (60)Cu, (61)Cu, (56)Ni, (57)Ni, (55)Co, (56)Co, (57)Co and (58)Co are presented and compared with earlier reported experimental data. Comparison with the recommended data reported by the International Atomic Energy Agency [Gul et al., 2001. Charged particle cross section database for medical radioisotope production. IAEA-TECDOC-1211, IAEA Vienna, Austria] is also presented when possible.     

The production of Xe via Xe(p,xn)Cs → Xe

Effective cross-sections for the production of ¹²⁷Cs in the bombardment of ^natXe with protons were measured from threshold up to 100 MeV. From the integral excitation function obtained, yield curves for ¹²⁷Xe, produced via the ^natXe(p,xn)¹²⁷Cs → ¹²⁷Xe route, were derived for a full range of gas target thicknesses. These curves can be used for the optimization of the production of ¹²⁷Xe within specific practical incident energy and target thickness constraints. The expected optimum yield for a representative production gas target (1.64 g/cm² thick) is 6.7 MBq/μAh (obtained at an incident energy of 39.3 MeV).     

Excitation functions for the production of some radioisotopes of Cs, Xe and I in proton bombardment of Xe up to 100 MeV

Integral excitation functions for the production of 16 radioisotopes of Cs, Xe and I in the bombardment of ^natXe with protons were measured up to 100 MeV. The results were compared with geometry-dependent hybrid-model calculations performed by means of the computer code ALICE/85/300, employing both the standard methods offered by the code to take nucleon pairing and shell-structure effects into account. Good overall agreement was obtained in both cases.     

Excitation functions of 125Te(p, xn)-reactions from their respective thresholds up to 100 MeV with special reference to the production of 124I.

Excitation functions of the nuclear reactions 125Te(p, xn) (119,120m, 120g, 121,122,123,124,125)I were measured for the first time from their respective thresholds up to 100 MeV using the stacked-foil technique. Thin samples were prepared by electrolytic deposition of 98.3% enriched 125Te on Ti-backing. In addition to experimental studies, excitation functions were calculated by the modified hybrid model code ALICE-IPPE. The experimental and theoretical data generally showed good agreement. From the measured cross section data, integral yields of (123,124,125)I were calculated. The energy range Ep 21 --> 15 MeV appears to be very suitable for the production of the medically interesting radionuclide 124I (T(1/2) = 4.18 d; I(beta)+ = 25%). The thick target yield of 124I amounts to 81 MBq/microA h and the level of 125I-impurity to 0.9%. The 125Te(p,2n)124I reaction gives 124I yield about four times higher than the commonly used 124Te(p,n)124I and 124Te(d,2n)124I reactions. The proposed production energy range is too high for small cyclotrons but large quantities of 124I can be produced with medium-sized commercial machines.     

Measurements and nuclear model calculations on proton-induced reactions on Rh up to 40 MeV: evaluation of the excitation function of the Rh(p,n)Pd reaction relevant to the production of the therapeutic radionuclide Pd

Excitation functions were measured by the stacked-foil technique for the reactions ¹⁰³Rh(p,n)¹⁰³Pd, ¹⁰³Rh(p,3n)¹⁰¹Pd and ¹⁰³Rh(p,4n)¹⁰⁰Pd from their respective thresholds up to 39.6 MeV. The radioactivity of the activation products was determined by high-resolution X-ray and γ-ray spectrometry. Statistical model calculations taking into account the precompound effects were performed for all reactions, and good agreement was found with our data. A critical evaluation of the existing and present data for the ¹⁰³Rh(p,n)¹⁰³Pd reaction was carried out. Recommended cross sections and integral yields for this reaction of key importance in the production of the widely used therapeutic radionuclide ¹⁰³Pd are given.     

Cross-section measurements for (n, 2n), (n, p) and (n, n′α) reactions on gallium isotopes in the neutron energy range of 13.5–14.6 MeV

Cross-sections for (n, 2n), (n, p) and (n, n'alpha) reactions have been measured on gallium isotopes at the neutron energies of 13.5-14.6MeV using the activation technique. Data are reported for the following reactions: 69Ga(n, 2n) 68Ga, 69Ga(n, p) 69mZn, 71Ga(n, p) (71m)Zn, and 71Ga(n, n'alpha) 67Cu. The neutron fluences were determined using the monitor reaction 93Nb(n, 2n) 92mNb.     

Spallation neutron emission spectra in medium and heavy target nuclei by a proton beam up to 140 MeV energy

In this study, neutron-emission spectra produced by (p,xn) reactions for some spallation neutron target nuclei such as ⁶⁵Cu, ^{204,206,207,208}Pb, ²⁰⁹Bi, ²³²Th and ²³⁸U have been calculated by a proton beam up to 140 MeV. Multiple pre-equilibrium mean free path constants from internal transition for ^204,208Pb (p, xn) neutron emission spectra have been investigated. In the calculations, pre-equilibrium effects were calculated by using new evaluated hybrid model and geometry dependent hybrid model, full exciton model and cascade exciton model. The reaction equilibrium component was calculated by Weisskopf–Ewing model. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.     

Investigation of the natZn(p,x)62Zn nuclear process up to 70 MeV: a new 62Zn/62Cu generator

The excitation function of the ^natZn(p,x)⁶²Zn nuclear process was measured by the stacked-foil technique up to a proton energy of 70 MeV to obtain accurate data for production of the ‘mother nuclide’ (⁶²Zn) of the PET related β⁺ emitting radioisotope ⁶²Cu. Investigations were also made on the ⁶⁶Zn(p,x)⁶²Zn and ^natZn(p,xn)⁶⁶Ga processes and on the ⁶⁶Zn(p,n)⁶⁶Ga reaction using ^natZn and highly enriched ⁶⁶Zn. The excitation functions were compared with the published data. Thick target yields for the ^natZn(p,x)⁶²Zn and ^natCu(p,xn)⁶²Zn processes were also calculated up to 70 MeV. On the basis of these calculations the ^natZn+p process results in higher yield for ⁶²Zn above 50 MeV than the ^natCu+p process. The latter process is presently used for practical production of ⁶²Zn. In an energy window from 70 to 30 MeV the available EOB yield of the ^natZn+p reactions is around 19 mCi/μA h (0.7 GBq/μAh) that makes the ^natZn(p,x)⁶²Zn process a good candidate for routine generator production.     

Excitation functions of 120Te(d,xn)121,120m,gI reactions from threshold up to 13.5 MeV: comparative studies on the production of 120gI.

Excitation functions of the nuclear reactions 120Te(d,xn)121,120m,gI were measured for the first time from their respective thresholds up to 13.5 MeV. Thin samples prepared by electrolytic deposition of 99.0% enriched 120Te on Ti-backing were used. Integral yields of 121,120m,gI were calculated from the measured cross section data. A comparison of the 122Te(p,3n)-, 120Te(p,n)- and 120Te(d,2n)-processes for the production of 120gI is given. The 120Te(d,2n)-process is unsuitable for production purposes since the yield of 120gI is very low and the level of 121I impurity very high. The choice lies either on the 122Te(p,3n)- or the 120Te(p,n)-reaction and is governed by the available proton energy and the financial resources for procuring the enriched target material.     

Excitation functions of (alpha,xn) reactions on (nat)Rb and (nat)Sr from threshold up to 26 MeV: possibility of production of (87)Y, (88)Y and (89)Zr.

Excitation functions were measured by the stacked-foil technique for (nat)Rb(alpha,xn)(87m,87m+g,88)Y and (nat)Sr(alpha,xn)(86,88,89)Zr reactions from their respective thresholds up to 26 MeV. The samples for irradiation were prepared by sedimentation and pellet pressing techniques. The measured data were compared with those available in the literature. From the excitation functions, integral yields of the products were calculated. The suitable energy ranges for the production of (87)Y and (88)Y via (nat)Rb(alpha,xn) processes and of (89)Zr via the (nat)Sr(alpha,xn) process are E(alpha)=26-->20 MeV, E(alpha)=26-->5 MeV and E(alpha)=20-->8.5 MeV, respectively. The respective yields amount to 8.2, 0.08 and 0.9 MBq/microA h. Production of (88)Y is feasible if a waiting time of about 2 months is allowed to let the impurities decay out. Also, (87)Y can be produced with a relatively low impurity of (88)Y. The yields of both (88)Y and (87)Y via the present routes are, however, appreciably lower than those via the (nat)Sr(p,xn) processes. There is a possibility to produce (89)Zr via the alpha-particle irradiation of (nat)Sr. The yield is rather low but would be considerably increased if enriched (86)Sr would be used as target material. The radionuclidic impurity levels in all the three products are discussed.     

Calculations for the excitation functions of 3-26 MeV proton reactions on 66Zn, 67Zn and 68Zn.

Calculation of excitation functions of 66Zn(p,n)66Ga, 66Zn(p,n + p)65Zn, 66Zn(p,2n)65Ga, 67Zn(p,2n)66Ga, 68Zn(p,n)68Ga, 68Zn(p,2n)67Ga natZn(p,xn)66Ga and natZn(p,xn)67Ga reactions has been carried out using the statistical and pre-equilibrium nuclear reaction models in the 3-26 MeV energy range. The calculational results are compared with the reported measurements and evaluations.