Excitation functions of proton-induced reactions on natFe and enriched 57Fe with particular reference to the production of 57Co

Excitation functions of the reactions ^natFe(p,xn)^55,56,57,58Co, ^natFe(p,x)⁵¹Cr, ^natFe(p,x)⁵⁴Mn, ⁵⁷Fe(p,n)⁵⁷Co and ⁵⁷Fe(p,α)⁵⁴Mn were measured from their respective thresholds up to 18.5 MeV, with particular emphasis on data for the production of the radionuclide ⁵⁷Co (T_1/2=271.8 d). The conventional stacked-foil technique was used, and the samples for irradiation were prepared by an electroplating or sedimentation process. The measured excitation curves were compared with the data available in the literature as well as with results of nuclear model calculations. From the experimental data, the theoretical yields of the investigated radionuclides were calculated as a function of the proton energy. Over the energy range E_p=15→5 MeV the calculated yield of ⁵⁷Co from the ⁵⁷Fe(p,n)⁵⁷Co process amounts to 1.2 MBq/μA h and from the ^natFe(p,xn)⁵⁷Co reaction to 0.025 MBq/μA h. The radionuclidic impurity levels are discussed. Use of highly enriched ⁵⁷Fe as target material would lead to formation of high-purity ⁵⁷Co.     

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 function of 3He-particle induced nuclear reactions on natural palladium

Excitation functions of ³He-particle induced nuclear reactions on natural palladium were measured using the standard stacked foil technique and high resolution γ-ray spectroscopy. From their threshold energies up to 27 MeV, cross-sections for ^natPd(³He,x)^{103,104,105,106m,110m,111,112}Ag and ^natPd(³He,x)^{104,105,107,111m}Cd reactions were measured. The nuclear model codes TALYS-1.4, and EMPIRE-3.1 were used to describe the formation of these products. The present data were compared to theoretical results and to the available experimental data. Integral yields for some important radioisotopes were determined.     

Activation cross sections of α-particle induced nuclear reactions on hafnium and deuteron induced nuclear reaction on tantalum: Production of 178W/178mTa generator

In the frame of a systematic study of charged particle production routes of medically relevant radionuclei, the excitation function for indirect production of ^178mTa through ^natHf(α,xn)¹⁷⁸W–^178mTa nuclear reaction was measured for the first time up to 40 MeV. In parallel, the side reactions ^natHf(α,x)^{179,177,176,175}W, ^{183,182,178g,177,176,175}Ta, ^{179m,177m,175}Hf were also assessed. Stacked foil irradiation technique and γ-ray spectrometry were used. New experimental cross section data for the ^natTa(d,xn)¹⁷⁸W reaction are also reported up to 40 MeV. The measured excitation functions are compared with the results of the ALICE-IPPE, and EMPIRE nuclear reaction model codes and with the TALYS 1.4 based data in the TENDL-2013 library. The thick target yields were deduced and compared with yields of other charged particle ((p,4n), (d,5n) and (³He,x)) production routes for ¹⁷⁸W.     

Neutron activation cross-sections for Ytterbium isotopes at (14.6±0.3) MeV

The cross-sections of ^natYb (n,x)^172,173 Tm, ¹⁷⁴Yb(n,p) ¹⁷⁴ Tm, ¹⁷⁴Yb (n,α) ¹⁷¹Er, ¹⁷⁶Yb(n,p) ¹⁷⁶ Tm, ¹⁷⁶Yb(n,α)¹⁷³ Er, and ¹⁷⁶ Yb(n,n′)^176mYb have been measured at 14.6±0.3 MeV neutron energy, among them two cross-sections ^natYb (n,x)^172,173Tm are reported for the first time. These experimental cross-sections are compared with experimental data found in the literature, with evaluated nuclear data in JENDL-4.0 and TENDL-2010 libraries and with theoretically calculated values based on nuclear reaction modular codes EMPIRE-3.0 and TALYS-1.2.     

Cross section measurements of proton and deuteron induced reactions on natural europium and yields of SPECT-relevant radioisotopes of gadolinium

The existing cross section data of the ^natEu(d,x) and ^natEu(p,x) reactions relevant for the production of ^147,149Gd were expanded up to 70.9 MeV and 44.8 MeV, respectively. Integral yields of radiogadolinium were calculated, showing production rates higher than for the earlier proposed irradiation of highly enriched ¹⁴⁴Sm with α- or ³He-particles. The formation of radioisotopic impurities like ¹⁵¹Gd (T_1/2=124 d) and ¹⁵³Gd (T_1/2=240 d) was below 5%. Production of ^147,149Gd using enriched europium is also discussed.     

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 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.     

Study of the Ni(p,x)Ni process up to 44 MeV for monitor Purposes

Cross sections have been measured from 14 up to 44 MeV for proton induced nuclear processes on natural nickel leading to the production of ⁵⁷Ni (T_1/2=36.1 h) using the stacked foil method. We have also investigated the contribution of background neutron induced reactions to the production of ⁵⁷Ni. On the basis of the presented experimental work and the available literature results it can be concluded that the ^natNi(p, x)⁵⁷Ni process can be used very effectively for monitoring proton beams in the investigated energy range.     

Study of the excitation function for the deuteron induced reaction on 64Ni(d,2n) for the production of the medical radioisotope 64Cu

The production of ⁶⁴Cu, a radioisotope of considerable interest for the application in nuclear medicine for PET imaging and radioimmunotherapy, was investigated by deuteron bombardment of enriched ⁶⁴Ni target up to E_d=20.5 MeV. The experimental excitation function for the reaction ⁶⁴Ni(d,2n)⁶⁴Cu was measured using the stacked foil irradiation technique followed by HPGe γ-ray analysis at 1346 keV and is compared with earlier literature values. Cross-section data for the ⁶⁴Ni(d,p)⁶⁵Ni reaction are determined for the first time. Thick target yields are derived and compared with results of other production routes.     

Simultaneous production of high specific activity 64Cu and 61Co with 11.4 MeV protons on enriched 64Ni nuclei

The ⁶⁴Cu and ⁶¹Co radionuclides were produced simultaneously by irradiation of enriched ⁶⁴Ni on a low energy proton-only cyclotron. Nickel targets were prepared by electrodeposition of enriched ⁶⁴Ni (>95%) on Au backing at thicknesses of 25–225 mg/cm² with efficiencies >99%. Irradiations up to 30 μA for 8 h were performed with 11.4 MeV protons using a water-cooled target mounting. Radiochemical separation of ⁶⁴Cu and ⁶¹Co from ⁶⁴Ni was performed by chromatography of the chlorocomplexes in a single step using an anion exchange resin column with a yield >95%. Using this method, the Ni target material was recovered and re-plated for subsequent production runs with an overall efficiency >96%. The excitation function for the ⁶⁴Ni(p,n)⁶⁴Cu reaction was measured and compared with published values. Experimental thick target saturation yields of 159 mCi/μA for ⁶⁴Cu and 715 μCi/μA for ⁶¹Co were achieved. Typical specific activities of ⁶⁴Cu were found to be 18.8±3.3 Ci/μmol.     

Calculation of induced reactions of 3He-particles on natSb in 10–34 MeV energy range

Calculations for the excitation functions of the ¹²¹Sb(³He, xn) ^121,122,123I, and ¹²³Sb(³He xn) ^{122,123,124,125}I reactions have been carried out using statistical and pre-equilibrium nuclear reaction models in 10−34 MeV energy range. These excitation functions have been used to derive the excitation functions of the ^natSb(³He, xn)^121,123,124I reactions and compared with reported measurements. For studying the improvement with measurements two values of the diffuseness parameter a_w equal to 0.9 and 0.7 fm have been used in the calculations. The dependence of pre-equilibrium calculations on the initial exciton numbers has also been considered.     

Excitation function of the 64Ni(α,p)67Cu reaction for production of 67Cu

The excitation function of the ⁶⁴Ni(α,p)⁶⁷Cu reaction was measured from threshold up to 24 MeV in order to investigate the possibility of production of the β⁻-emitting therapeutic radioisotope ⁶⁷Cu (T_1/2=61.9 h). Two stacks of thin metallic self-supporting foils of ⁶⁴Ni (enrichment 77.8%) prepared by electrolytic deposition were irradiated by α-particle beams. The radioactivity was determined via HPGe detector γ-ray spectrometry. Some ⁶⁷Ga activity (which emits the same γ-rays as ⁶⁷Cu), formed via the ^natCu(α,x)⁶⁷Ga process on trace copper impurity in the Ni foils, was also observed. Corrections were done for ⁶⁷Ga activity contribution and for the ⁶⁷Cu activity escape fraction from the thin Ni-foil. The maximum cross section of the ⁶⁴Ni(α,p)⁶⁷Cu reaction amounts to 34 mb at 22 MeV. The experimental results were compared with theoretical predictions. The integral yield of ⁶⁷Cu at 24 MeV α-particle energy, calculated from the excitation function, amounts to 544 KBq/μAh (48.5 MBq/μA at saturation). It is thus a low-yield reaction.     

Investigation of production of the therapeutic radioisotope 165Er by proton induced reactions on erbium in comparison with other production routes

The excitation function of the ^natEr(p,xn)¹⁶⁵Tm reaction resulting in production of ¹⁶⁵Er was measured up to 70 MeV by activation of stacked foils practically for the first time. The theoretical interpretation is based on the results of the ALICE-IPPE and EMPIRE-II codes. From the measured experimental cross section data integral production yield was calculated and compared with experimental integral yield data reported in the literature. Different production routes of the therapeutic radioisotope ¹⁶⁵Er were compared.     

Experimental studies and nuclear model calculations on proton induced reactions on manganese up to 45 MeV with reference to production of 55Fe, 54Mn and 51Cr

Excitation functions of the reactions ⁵⁵Mn(p,n)⁵⁵Fe, ⁵⁵Mn(p,x)⁵⁴Mn and ⁵⁵Mn(p,x)⁵¹Cr were measured from their respective thresholds up to 18 MeV in the first case and up to 45 MeV in the latter two cases, using the conventional stacked-foil technique. The radioactivity of ⁵⁵Fe was determined via high resolution X-ray spectrometry and of other radionuclides via high resolution γ-ray spectrometry. Nuclear model calculations were performed using the codes ALICE-IPPE, EMPIRE and TALYS. In some cases, good agreement was found between the experimental and theoretical data while in others considerable deviations were observed. From the experimental data the expected integral yields of the three investigated radionuclides were calculated.     

Production cross sections of niobium and tantalum isotopes in proton-induced reactions on natZr and natHf up to 14 MeV

Production cross sections of Nb and Ta isotopes in the proton-induced reactions on ^natZr and ^natHf, respectively, were measured up to 14 MeV using a stacked-foil technique. The observed nuclides in the ^natZr(p,x) reactions were ^{90g,91m,92m,95m,95g,96}Nb, ⁹⁵Zr, and ^87g,88Y. In the ^natHf(p,x) reactions, ^{175,176,177,178,179}Ta and ¹⁷⁵Hf were observed. The obtained cross sections for each nuclide were compared with the previously reported data and with the theoretical cross sections calculated by the TALYS-1.4 code. Thick-target yields of the observed nuclides were deduced from the measured production cross sections.     

Separation of no-carrier-added 93,94,94m,95,96Tc from 7Li induced natural Zr target by liquid–liquid extraction

Charged particle activation was carried out on ^natZr foil by 42.5 MeV ⁷Li beam to produce ^{93,94,94m,95,96}Tc radionuclides. No-carrier-added (nca) technetium radionuclides were separated from co-produced ^90,96Nb and bulk Zr employing liquid–liquid extraction with the help of anion exchanger trioctylamine (TOA) diluted in cyclohexane and HCl. Bulk Zr was monitored by spiking ^88,89Zr produced by 20 MeV proton induced reaction on ^natY target. The optimum separation was achieved at 0.1 M TOA and 0.01 M HCl. Technetium radionuclides were recovered from the TOA phase by stripping with 0.1 M DTPA (diethylene triamine pentaacetic acid) dissolved in NaOH.     

Excitation functions of 3He- and α-particle induced nuclear reactions on natSb for production of medically relevant 123I and 124I radioisotopes

Excitation functions were measured using the stacked foil irradiation technique from threshold energies to 28 MeV for ³He- and to 21 MeV for α-particle induced nuclear reactions on natural antimony leading to the formation of ^121,123,124I radioisotopes. The measured excitation functions were compared with the contradicting results of the earlier investigations found in the literature and with the curves predicted by the ALICE-IPPE and EMPIRE-II codes. Integral yields were also calculated and compared with the experimental thick target yields reported in the literature.     

Measurements of 186Re production cross section induced by deuterons on natW target at ARRONAX facility

IntroductionThe ARRONAX cyclotron, acronym for “Accelerator for Research in Radiochemistry and Oncology at Nantes Atlantique” is a new facility installed in Nantes, France. A dedicated program has been launched on production of innovative radioisotopes for PET imaging and for β − and α targeted radiotherapy using protons or α particles. Since the accelerator is also able to deliver deuteron beams up to 35 MeV, we have reconsidered the possibility of using them to produce medical isotopes. Indeed, in some cases, the use of deuterons allows higher production yield than protons.Methods¹⁸⁶Re is a β − emitter which has chemical properties close to the widely used ^99mTc and has been used in clinical trials for palliation of painful bone metastases resulting from prostate and breast cancer. ¹⁸⁶Re production cross section has been measured between 9 and 23 MeV using the ARRONAX deuteron beam and the stacked-foil technique.A novelty in our work is the use of a monitor foil behind each ^natW target foil in order to record efficiently the deuteron incident flux and energies all over the stack relying on the International Atomic Energy Agency (IAEA) recommended cross section of the ^natTi(d,x)⁴⁸V reaction. Since a good optimization process is supposed to find the best compromise between production yield and purity of the final product, isotope of interest and contaminants created during irradiation are measured using gamma spectrometry.ResultsOur new sets of data are presented and compared with the existing ones and with results given by the TALYS code calculations. The thick target yield (TTY) has been calculated after the fit of our experimental values and compared with the IAEA recommended ones.ConclusionsPresented values are in good agreement with existing data. The deuteron production route is clearly the best choice with a TTY of 7.8 MB/μAh at 30 MeV compared to 2.4 MBq/μAh for proton as projectile at the same energy. The TALYS code gives satisfactory results for ^183,186Re isotopes.     

An Am/Be neutron source and its use in integral tests of differential neutron reaction cross-section data

An Am/Be neutron source, installed recently at the Rajshahi University, is described. Neutron flux mapping was done using the nuclear reactions ¹⁹⁷Au(n,γ)¹⁹⁸Au, ¹¹³In(n,γ)^114mIn, ¹¹⁵In(n,n′γ)^115mIn and ⁵⁸Ni(n,p)⁵⁸Co. An approximate validation of the neutron spectral shape was done using five neutron threshold detectors and the iterative unfolding code SULSA. Integral cross sections of the reactions ⁵⁴Fe(n,p)⁵⁴Mn, ⁵⁹Co(n,p)⁵⁹Fe and ⁹²Mo(n,p)^92mNb were measured with fast neutrons (E_n>1.5 MeV) and compared with data calculated using the neutron spectral distribution and the excitation function of each reaction given in data libraries: an agreement within±6% was found.