Excitation function measurements and integral yields estimation for natZn(p,x) reactions at low energies

https://doi.org/10.1016/j.apradiso.2007.05.004Get rights and content

Abstract

Excitation functions have been measured for a number of proton-induced nuclear reactions on natural zinc in the energy range from 27.5 MeV down to their threshold energy, using the activation method on stacked foils. Excitation functions and thick target yield for the reactions leading to the formation of 67Ga,66Ga,68Ga,62Zn and 65Zn are presented and compared with earlier reported experimental data. The experimental cross-sections and the production yields are tabulated; the excitation functions and the thick target yield curves are plotted in graphs.

Introduction

Recently, the status of nuclear data for medical radioisotopes produced by accelerators has been reviewed by Gandarias-Cruz and Okamoto (1988), Qaim (2001), Qaim et al. (2002) and Takács et al. (2005). This summarizes available data on experimental measurements of cross-sections and thick target yields for medical radioisotopes of current interest besides the presentation of exhaustive reference material. The statues also shows that although many reactions were frequently studied in the past, especially in the above-mentioned energy range, results of new precise cross-sections certainly could be useful for some data bases even for the most commonly used radioisotopes including 67Ga, 111In, 123I and 201Tl.

The three radioisotopes 66Ga, 67Ga and 68Ga are well known and widely used in the field of nuclear medicine. 67Ga has become one of the most frequently employed cyclotron produced radioisotope over the last two decades (Ruth et al., 1989; Taylor and McCready, 1986) and is a widely used single photon marker for detecting the presence of malignancy and for diagnosis of inflammatory diseases (Hoffer, 1980; Noujaim et al., 1981). The positron emitter 68Ga, usually obtained through a 68Ge (t1/2=288 d)→68Ga generator, is employed at PET centers for blood–brain barrier investigations, in diagnostics of some tumor diseases of liver and other organs (Qaim, 1987) and for transmission measurements for encoding calibration and normalization of detector efficiencies of PET scanners. Recently, 66Ga was proposed for studying some slow dynamic processes by PET (Goethals et al., 1988). It is noticed that the use of natural zinc for practical purposes is very limited because of the lower yield and/or high contaminations.

This article reports on the cross-sections and production yields of 66Ga, 67Ga, 68Ga, 62Zn and 65Zn, which have been measured in our laboratory for the compilation of the existing data base. The cross-sections and the production yields are plotted in the energy range from 3.7 to 27.5 MeV to give the excitation functions and thick target yield functions for 66Ga, 67Ga, 68Ga, 62Zn and 65Zn in natural zinc. The results and the relevant errors are compared with the data published in the literature.

Section snippets

Experimental technique

The excitation functions of the natZn(p,x) reactions were measured by the well known stacked foil irradiation technique (Gul et al., 2001; IAEA TECDOC-1211). Targets were prepared via electrolytic deposition of natural zinc on commercially high purity natural Ni foils (99.9%) from Goodfellow Metals Ltd., UK. The stacks of thickness (12.6 μm) were used as targets (circular foils of 10 mm diameter). Natural Cu and Al foils of varying thickness were sometimes inserted into the stacks as energy

Results and discussions

The decay characteristics and half-live of the resulting isotopes are summarized in Table 1 with Q-values and threshold energies of the contributing reactions (Chu et al., 1999). The resulting reaction cross-sections with the corresponding proton energies are presented in Table 2.

Integral yields

The integral yields for the reactions leading to 67Ga, 66Ga, 68Ga, 62Zn and 65Zn were calculated during this work using the present measured excitation functions. The results are shown in Fig. 6. Although the production of 67Ga for medical uses is practically impossible from natural zinc target, the following remarks could be considered from the figure. The ratio of the produced 62Zn and 65Zn impurities with the required 67Ga isotope is small and they could be chemically separated. The isotopic

Conclusions

New cross-section data have been measured in the energy range from 3.7 to 27.5 MeV for five reaction products from the natZn(p,x) reactions. The selected cross-section data sets show very good agreement with most of the previous studies over the specified energy region, while some other data set could not be confirmed. 67Ga should be produced with high integral yield in the energy range between 15.0 and 27.5 MeV. The estimated integral yield according to the specified energy region was about (49 

Acknowledgments

The authors would like to thank Dr. Al-Sudairy Sultan (Chairman of the KFSH Research Center) for providing us the opportunity to use the cyclotron facility for target irradiation. Also, thanks to the cyclotron staff, Eng. Miliebari Salman (Section Head) Eng. Rahma Salama and Eng. Al-Ghaith Ahmed, for their great help during the irradiation.

References (33)

  • S. Takács et al.

    Validation and upgrading of the recommended cross-section data of charged particle reactions: gamma emitter radioisotopes

    Nucl. Instr. and Meth. Phys. Res. Sec. B: Beam Interact. Mater. Atoms

    (2005)
  • F. Tárkányi et al.

    Activation cross-sections of long-lived products of proton-induced nuclear reactions on zinc

    Appl. Radiat. Isot.

    (2005)
  • Al-Abyad, M.E., 2003. Nuclear reactions studies on some natural targets using cyclotron. Master Thesis, Physics...
  • F.S. Al-Saleh et al.

    Excitation functions of proton induced nuclear reactions on natural copper using medium-size cyclotron

    Radiochim. Acta

    (2006)
  • H.H. Anderson et al.
    (1977)
  • Barandon, J.N., Debrun, J.L., Kohn, A., Spear, R.H., 1975. Etude du dosage de Ti, V, Cr, Fe, Ni, Cu, et Zn par...
  • Cited by (28)

    • Measurement of cross sections for proton-induced reactions on natural Zn

      2019, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
    • Assessment and estimation of <sup>65</sup>Zn production yield via neutron induced reaction on <sup>nat</sup>ZnO and <sup>nat</sup>ZnONPs

      2018, Applied Radiation and Isotopes
      Citation Excerpt :

      Some of the 65Zn research studies can be mentioned such as zinc metabolism research at the site of vascular repair in rats (Pories et al., 1979), Calcium control of zinc absorption in both gills and whole body of rainbow trout (Barron et al., 2000), zinc biodistribution in humans (Reeves et al., 2001), study of in vitro binding of 65Zn in normal, hyperplastic, and carcinoma prostate gland in human (Györkey et al., 1968). This radioisotope can be used in other applications such as agriculture (Haslett et al., 2001; Brambilla et al., 2002, 2003; Jiang et al., 2007), as a tracer in thin layer activation technique (Al-Saleh et al., 2007) and a standard source for calibration of gamma spectroscopy (Sahagia et al., 2004; Van Ammel et al., 2004). The main objective of this research was application of nanoparticles for 65Zn production to compare the activity value of this radionuclide with bulk state target in same conditions.

    • Assessment of the production of medical isotopes using the Monte Carlo code FLUKA: Simulations against experimental measurements

      2016, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
      Citation Excerpt :

      Since the threshold for the reactions 68Zn(p,2n)67Ga and 70Zn(p,3n)68Ga are respectively 12.158 and 19.68 MeV [40], the assumption that the (p,n) reactions are the only ones that contribute significantly to the production of the two isotopes is confirmed. The uncertainty of the cross section data is on average about 10% [40] for both reactions. The cross section data were obtained with the “stack-foils method” [38] but do not cover the entire energy range up to 13 MeV necessary.

    • Measurements of <sup>67</sup>Ga production cross section induced by protons on <sup>nat</sup>Zn in the low energy range from 1.678 to 2.444 MeV

      2015, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
      Citation Excerpt :

      Accordingly, the overall uncertainty of the data obtained is significantly reduced because the knowledge of experimental parameters that usually have large uncertainties, like detector efficiency, solid angle sustained by the detector, and attenuation coefficients, are avoided. It is worth mentioning that for this nuclear reaction, previous studies such as those found in Ref. [9,10,5,11–13] attained higher energies and only Ref. [14] reports data below 3 MeV. Following this line of research, the results obtained in this study are then compared to both, data available in the literature and to those derived from both ALICE/ASH [15] and Talys-1.6 [16] nuclear codes.

    View all citing articles on Scopus
    View full text