F. Tárkányi

Excitation functions of 124Te(p, xn)124,123I reactions from 6 to 31 MeV with special reference to the production of 124I at a small cyclotron

Abstract Excitation functions were measured by the stacked-foil technique for (p, xn) reactions on highly enriched 124Te in the proton energy range of 6–31 MeV. Thin uniform films of 24Te on Ti-backing were prepared by an electrodeposition method. Above 17 MeV our data agree within experimental errors with the literature values, thus validating the 123I-yields and 124I-impurity levels associated with the 124Te(p, 2n)123I production process. Detailed measurements near the threshold of the 124Te(p, n)124I reaction, on the other hand, show that, contrary to the general assumption, the thick target yield of 124I is fairly high, amounting to 20 MBq (0.54 mCi)/μAh over the optimum energy range Ep = 13 → 9 MeV. A comparison of the three suggested routes for the production of 124I, viz. 124Te(d, 2n)-, 126Te(p, 3n)-, and 124Te(p, n)-processes, is given. The yield and impurity-level data suggest that the 124Te(p, n)124I reaction has a great potential for production at a small cyclotron.

Evaluation of proton induced reactions on 100Mo: New cross sections for production of 99mTc and 99Mo

The use of the 99Mo→99mTc generator in nuclear medicine is well established world wide. The production of the 99Mo (T1/2 = 66 h) parent as a fission product of 235U is largely based on the use of reactor technology. From the early 1990s accelerator based production methods to provide either direct produced 99mTc or the parent 99Mo, were studied and suggested as potential alternatives to the reactor based production of 99Mo. A possible pathway for the charged particle production of 99mTc and 99Mo is irradiation of molybdenum metal with protons via the reaction 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo, respectively. The earlier published excitation functions show large differences in their maximum that result in large differences in the calculated yields. We therefore decided to study the excitation function for these proton-induced reactions. In this work the newly measured excitation functions as well as an evaluation of earlier measured data and a discussion of the observed disagreements are presented.

New cross-sections and intercomparison of deuteron monitor reactions on Al, Ti, Fe, Ni and Cu

Abstract The 27Al(d,x)22,24Na reactions are frequently used to monitor deuteron beams above 20 MeV. To extend possible monitoring energy region toward lower energies, new monitor reactions are proposed and experimental cross-sections are measured for the processes 27Al(d,x)22,24Na, natTi(d,x)48V, natFe(d,x)56Co, natNi(d,x)61Cu and natCu(d,x)65Zn. The excitation functions were studied using the activation method on stacks of thin metallic foil targets with natural isotopic composition. The data sets of the six processes were cross-checked with each other to provide reliable numerical cross-sections. Detailed literature compilation and critical comparison were made on the available data sets for the studied reactions. Predictions of model calculations were compared with the new experimental data. After establishing selection criteria, consistent data sets were chosen for each of the processes, which were then fitted with a spline or Pade method to provide recommended cross-sections.

New cross-sections and intercomparison of proton monitor reactions on Ti, Ni and Cu

Abstract The excitation functions of proton induced reactions on Ti, Ni and Cu were studied using activation method on stacks made of thin metallic foil targets with natural isotopic composition. Since titanium, nickel and copper are ideal target material with respect to their availability, physical, mechanical and chemical properties the use of the nat Ti(p,x) 48 V, nat Ni(p,x) 57 Ni, nat Cu(p,x) 62 Zn, nat Cu(p,x) 63 Zn and nat Cu(p,x) 65 Zn processes are suitable for monitoring the intensity and/or energy of charged particle beams. These processes are recommended under 40 MeV bombarding proton energy as monitor reaction. The new data sets of these five processes were cross-checked with each other to provide reliable consistent numerical cross-sections. Results were compared to the recommended cross-section values reported recently by the International Atomic Energy Agency [IAEA TECDOC-1211, 2001].

Experimental studies on excitation functions of the proton-induced activation reactions on yttrium

Proton-induced activation cross-sections were measured for the (89)Y(p,x)(89,88,86)Zr, (89)Y(p,x)(88,87,87 m,86)Y, (89)Y(p,x)(85,83,82)Sr and (89)Y(p,x)(84,83)Rb reactions by a stacked foil technique in the energy range 15-80 MeV which was covered by two separate measurements for 15-50 and 32-80 MeV energy range with 50 and 80 MeV incident protons. The differences between the results of two irradiations were found within 6% in the overlapping energy regions. The production yields for the long-lived products like (88)Zr, and (88)Y are significantly larger than that of (nat)Mo+p, (nat)Nb+p and (nat)Zr+p processes. The productions of the medical isotopes, (85)Sr and (83)Sr are also effective by Y+p process using an 80 MeV beam. Thick target integral yields were also deduced using the measured cross-sections. The (87)Y, (88)Y, (88)Zr and (89)Zr radionuclides have suitable yields and decay characteristics important for thin-layer activation (TLA) analysis.

Excitation functions of deuteron induced nuclear reactions on natural zinc up to 50 MeV

Excitation functions were measured for production of 66,67Ga, 62,65,69mZn, 61,64,67Cu and 58Co radioisotopes in deuteron induced reactions on natural Zn up to 50 MeV by activation using stacked foil techniques. Detailed compilations were made of the earlier reported experimental cross-section and integral yield data. They are compared with the new values and theoretical calculations. The use of the measured formation cross-section for production of practically important radioisotopes of gallium and copper is discussed as well as the application of cross-section data of 65Zn in the field of wear monitoring by the thin layer activation method.

Excitation function of the 18O(p,n)18F nuclear reaction from threshold up to 30 MeV

The available experimental data on the most common route for the production of 18F, viz. 18O(p,n)18F reaction, obtained both via neutron spectral studies and activation measurements, were critically reviewed. In some energy regions the cross section database was found to be rather weak or discrepant. In order to fill the gaps and to clear some of the discrepancies, the excitation function was remeasured from threshold up to 30 MeV using different solid and gas targets containing highly enriched 18O. For this purpose a van de Graaff machine (Ep <4 MeV) and several cyclotrons (Ep = 4-30 MeV) were utilized. The new experimental data help to prepare a recommended data set. At Ep = 14 MeV the integral yield of 18F calculated from the new excitation curve is slightly higher than that from the hitherto accepted data set; at Ep > 14 MeV the yields reported here are new.

New cross section data on68Zn(p, 2n)67Ga andnatZn(p,xn)67Ga nuclear reactions for the development of a reference data base

Excitation functions were measured by stacked-foil technique for the68Zn(p, 2n)67Ga,68Zn(p,3n)66Ga,natCu(p,xn)62Zn,natZn(p,xn)67Ga,natZn(p,xn)66Ga,natZn(p,px)62Zn andnatZn(p,αx)61Cu nuclear reactions in the energy range from 15–35 MeV. The experimental excitation functions were compared with published data. Our present measurements not only increase the number of available cross section data points for the above reactions, but for some reactions (and in some energy regions) values are presented for the first time.

Excitation functions of (p, xn) reactions on natTi: Monitoring of bombarding proton beams

Abstract Excitation functions have been measured for the natTi(p, x)48V nuclear process by the stacked-foil technique in the energy range up to 30 MeV for use as a monitor reaction for proton beams. The intercomparison shows good agreement with other monitor reactions (p + natCu, p + natNi) over the whole energy range. Excitation functions for the production of 47Sc, 44mSc, 44gSc and 43Sc isotopes and the isomeric cross section ratio of 44mSc/44gSc were also determined in the energy range from 9.0 to 17.5 MeV.

Excitation Functions of Proton Induced Nuclear Reactions on Enriched 66Zn, 67Zn and 68Zn: Production of 67Ga and 66Ga

Excitation functions wäre measured for proton induced nuclear reactions on enriched ®®Zn, and over the energy ränge of 6—22 MeV using the activation method. The experimental cross section data were compared with published data and with the theoretical predictions. Thick target yields of and ®®Ga were calculated and compared with experimental yields. A chemical Separation procedure from enriched Zinc-targets is also presented.