Experimental Results Evaluation and Theoretical Study for the Production of the Radio Isotope 52 Mn Using P, D and Α- Projectiles on V and Cr Targets

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1 Experimental Results Evaluation and Theoretical Study for the Production of the Radio Isotope Mn Using P, D and Α- Projectiles on V and Cr Targets A.A. Alharbi Physics Department, Faculty of Sciences, Princess Nora Bint Abdulrahman University, Riyadh, Saudi Arabia. Received: 5/1/2016 Accepted: 20/2/2016 ABSTRACT 1 Mn is a very important radioisotope in medical applications. The different routes for production of this isotope, via nuclear reactions using p, d, 3 He and α, as projectile were studied in this work. Evaluation of the existing excitation functions of the different reactions as well as present TALYS 1.4 and EMPIRE 3.1 code calculations are presented. Cr(p, n), Cr(d,2n) and 51 V(α,n) nuclear reactions are taken into consideration. Recommended excitation functions and thick target yields for both ground and isomeric states are given. Keywords: Mn, Nuclear Reaction Cross Sections, Excitation Function, Radio Isotope Production. 1-INTRODUCTION Positron (β + ) emitter radionuclides are very important in nuclear medicine. Production of possible β + emitters were discussed by several authors (e.g): Lamberecht (1979) (2) and Qaim (2004) (1). g,m Mn is commonly used for PET diagnostics, since g Mn is a positron emitter with half-life of 5.59d and m Mn is a positron emitter with half-life of 21.1 m. This isotope could be produced through different nuclear reactions, using different projectile target combinations, at low energy cyclotron (projectile energy less than 30 MeV), In the present work, the available existing experimental works for the excitation function measurements of such nuclear reactions are presented, discussed, and then the more reasonable data are averaged. The Excitation functions are also calculated using TALYS 1.4 and EMPIRE 3.1 codes. The experimental calculations and code calculations are compared. Thick target yield were estimated based on the discussed excitation functions and promising production routes were proposed. 2-CODES DESCRIPTION In the following TALYS 1.4 and EMPIRE 3.1 codes are used for excitation function calculations and the bases of each code are summarized TALYS-1.4 Code TALYS-1.4 code, developed by Koning et al (2012) (3) is a computer program that simulates all types of nuclear reactions in the energy range of 1 kev-200 MeV. It incorporates modern nuclear models for the level densities, direct reactions, compound reactions, pre-equilibrium reactions, fission reactions, optical model, and a large nuclear structure database. The database of this code is derived from the reference input parameter library. The pre-equilibrium particle emission is described using the two-component exciton model. The model implements new expressions for internal transition rates and new parameterization of the average squared matrix element for the residual interaction obtained using the optical model potential. The phenomenological model is used for the description of the preequilibrium complex particle emission. The contribution of the direct processes in inelastic scattering is calculated using the ECIS-94 code incorporated in TALYS-1.4. The equilibrium particle emission is 1 Author abeer.alharby@gmail.com 612

2 described using the Hauser-Feshbach model. The default optical-model potentials (OMP) used in TALYS-1.4 are the local and the global parameterizations for neutrons and protons. These parameters can be adjusted in some cases by the user. The present results of all the calculated excitation functions were evaluated using the default values of the code EMPIRE-3.1 Code EMPIRE- 3.1 Rivoli developed by Herman et al (4) is a modular system of nuclear reaction codes, comprising various nuclear models, and designed for calculations over a broad range of energies and incident particles. The system can be used for theoretical investigations of nuclear reactions as well as for nuclear data evaluation work. Photons, nucleons, deuterons, tritons, helions ( 3 He), α, and light or heavy ions can be selected as projectiles. The energy range starts just above the resonance region in the case of a neutron projectile, and extends up to few hundred MeV for heavy ion induced reactions. The code accounts for the major nuclear reaction models, such as optical model, Coupled Channels and DWBA (ECIS06), Coupled Channels' Soft-Rotator (OPTMAN), Multi-step Direct (ORION + TRISTAN), NVWY Multi-step Compound, exciton model PCROSS, hybrid Monte Carlo simulation (DDHMS), and the full featured Hauser-Feshbach model including the optical model for fission. Heavy ion fusion cross section can be calculated within the simplified coupled channels approach (CCFUS). A comprehensive library of input parameters based on the RIPL-3 library covers nuclear masses, optical model parameters, ground state deformations, discrete levels and decay schemes, level densities, fission barriers, and γ-ray strength functions. Effects of the dynamic deformation of a fast rotating nucleus can be taken into account in the calculations (BARFIT, MOMFIT). 3. RESULTS AND DISCUSSIONS The decay characteristics of g Mn and m Mn radionuclide are listed in table 1. Table (1): Decay characteristics of g&m Mn (5) Isotope Half life Decay mode g Mn d m Mn 21.3m EC (65%) Β + (35%) Β + (98.32%) IT (1.68%) Gamma ray Energy(keV) Intensity (%) Mn radionuclide could be produced through different nuclear reactions with different projectile targets combinations. In the following section, the different production routes will be discussed Cr(p,n) g,m Mn The excitation function of Cr(p, n) reaction was studied with different authors, Tanaka et al (1959) (6), Linder and James (1959) (7), Wing, J. and Huizenga, G.R.(1962) (8) and Skakun et al (1986) (9). The data of Tanaka et al, represent the sum of formation cross sections for the isomeric and ground states of Mn.These data seem to be more close to cross section data of the isomeric state than to the total cross section data and they are excluded. The data from Sakakun et al represent the cross sections for both the isomeric and ground states as well as the total formation cross section. The ground state data seem to be consistent with other data from different references, while that for the isomeric state and consequently the total are lower than the others. Data of Linder and James, and Wing and Huizenga are close to each other and to the theoretical calculations for the ground, isomeric states, and hence to the total cross section. These data are averaged and presented in figure

3 Cross section (mb) Cr(p,n) g&m Mn Tanka (1959) Lnder (1959)-total Linder- m Linder-g Wing (1962) Wing-m Wing-g Skakun (1986) Skakun-g Skakun-m TALYS total TALYS m TALYS g EMPIRE total average Proton energy (MeV) Fig. (1): Excitation function of the Cr(p,n) g,m Mn reaction The cross section data for the isomeric state of Mn taken from Linder (1959) (7) and Wing (1962) (8) are very close to the calculated TALYS code data for the same states. For the ground state, the data of Linder (1959) are higher than that of the calculated TALYS data for energies higher than 10 MeV, while those of Linder (1959) seem to agree well with the calculations. The EMPIRE code calculations gave maximum cross section value, somehow, higher than the calculated average, while the total shape of the curve matched the average curve. The average total cross section data for the Cr(p,n) m&g Mn reaction are given in table 2. The calculated isomeric formation ratio is about 0.73, on the average, the average data for energies higher than 15 MeV, are extrapolation of the curve, since no experimental data in this energy range were found. It should be also mentioned that, the produced Mn through this reaction will be contaminated with the 51 Mn isotope, for energies higher than 14.5 MeV, which is corresponding to the threshold energy of the Cr(p,2n) 51 Mn reaction. The produced impurity isotope 51 Mn (T 1/2 =46.7 m) will decay completely after about 5 hours leaving g Mn ( T 1/2 = 5.59 d) as a radioactive pure isotope. 3.2 Cr(d,2n) g,m Mn The excitation function of Cr(d,2n) reaction was studied by different authors, Burgus et al., (1954) (10), ChengXiaowu et al. (1966) (11), Cogneau (1966) (12), Nassiff et al. (1973) (13) and West et al (1987) (14). All studied reactions are mentioned with the ground state formation cross section. The excitation function referring to these authors as well as the present calculations, using TALYS 1.4 and EMPIRE3.1, are presented in figure 2. All experimental data seem to be close to each other, within the experimental errors (12 15%), except those reported by Nassiff et al. (1973). These data are averaged and presented as solid line in figure 2. and reported in table 2. The reported data, by Nassiff 612

4 et al seem to be higher than the others by about 250 % and shifted by about 1.5 MeV towards higher energy. This may be due to an error in the current measurement or monitoring reaction results. These data are normalized and shifted by 1.7 MeV towards lower energy and became fitting nice with other data and used for getting the average recommended excitation function which is given in table 2. The estimated average coincides with the TALYS calculation for the formation of ground state. The calculated isomeric formation ratio is about 0.4 on the average. 600 Cr(d,2n) g&m Mn Burgus-g Che ngxiaowu-g 1966 Cogne au-g Nassiff-g+2%m 1973 Cross section (mb) Normalized Nassiff West-g 1987 ave rage EMPIRE TALYS-Total TALYS-g Deutron energy (MeV) TALYS-m V (α,3n) Mn Fig. (2): Excitation function for the Cr(d,2n) g,m Mn reaction Only Dmitriev et al, (1969) (15) studied this reaction in the energy range from threshold up to 40.8 MeV. The measured cross section data as well as the present code calculations are presented in figure 3. It could be seen from the figure that both TALYS and EMPIRE code calculations gave higher cross section values than that measured by Dmitriev et at. The data are fitted and given in table 2. EMPIRE code calculations gave closer shape to the experimental excitation function, since the maximum cross section position seems to be coincided at about 41 MeV, while TALYS calculation had maximum value at about 36 MeV. The calculated isomeric ratio for the production of the ground state was found to be about 90%. 612

5 Table (2): The average recommended excitation functions for different reactions leading to the formation of g,m Mn medical radioisotope. The error of the cross section values is estimated to be about 15%. E (MeV) Cr(p,n) g Mn Cr(p,n) m Cr(p,n) t M Cr(d,2n) g Mn n Mn 51 V(α,3n) g Mn σ(mb) E (MeV) σ(mb)

6 Yield (MBq / μμah) Cross cection (mb) Arab Journal of Nuclear Science and Applications, 94 (3 ), ( ) V(A,3n) Mn Dmitriev 1969 TALYS-g EMPIRE- total TALYS-total α-energy (MeV) Fig. (3): Excitation function of the 51 V (α,3n) Mn reaction 3.4 Thick Target Yield The estimated production yields for Mn from Proton, deuteron and alpha induced reactions were estimated based on the calculated recommended average or code calculated excitation functions (in few cases) and presented in fig.4 and table 3.. The yield for the Cr(p,2n) g Mn reaction based on the calculated average (for energies less than 10.5 MeV) and TALYS code calculated excitation functions (for energies between 10.5 and 16 MeV) gave a value of about (10.6 MBq/μAh) at about 16 MeV. While this reaction gives impurity, free Mn only for energies less than 14.5 MeV. The produced yield value for this energy range is only (5.5 MBq/μAh). The Cr(p,n) m Mn reaction gave a yield value of about (6357 MBq/μAh and 5300 MBq/μAh), based on the estimated average excitation function, at proton energies of about 16 and 14.5 MeV respectively. The isotopic impurity free m Mn could only be produced through the Cr(d,2n) gmn reaction for energies less than 21 MeV. The yield value is about (22 MBq/μAh and 19 MBq/μAh), for deuteron energies of 22.5 and 21 MeV respectively. The 51 V (α,3n) g Mn reaction gives a yield value of about 315 MBq/μAh at α- energy of about 42 MeV. Above this energy, the product will contain 51 Mn, as isotopic impurity, from the 51 V (α,4n) 51 Mn reaction Cr(p,n)mMn Crp,n)gMn Cr(d,2n)gMn 51V(A,3n)Cr Particle energy (MeV) Fig. (4): Estimated thick target yield for different reactions leading to the formation of Mn 661

7 Table (3): Estimated thick target yield (MBq/μAh) for different reactions leading to the formation of Mn.The estimated yield error values were about 15% E (MeV) Cr(p,n) g M n Cr(p,n) m Mn Cr(p,n) t M n Yield (MBq / μah) Cr(d,2n) g M n V(α,3n) g Mn E (MeV) Yield CONCLUSION The production of g,m Mn radioisotope through p, d or α- particle induced reactions on Cr or V target represents satisfactory routs. The existing excitation functions data for the Cr(p,2n) g,m Mn, Cr(d,2n) g Mn and 51 V (α,3n) g Mn reaction need more improvements, since their existence is only few and are not up-to-date. Average recommended excitation functions and estimated thick target yields are given in the present work. TALYS 1.4 and EMPIER 3.1 codes are used for describing these excitation functions. The code calculations give in general satisfied description for the experimental works specially for the Cr(p,2n) g,m Mn and, Cr(d,2n) g Mn reactions.talys calculation for the 666

8 51 V (α,3n) g Mn reaction gave a remarkably higher cross section than the only existing experimental work. The existence of the isotopic impurity 51 Mn radioisotope is discussed. REFERENCE (1) Lamberecht RM. (1979): Positron emitting radionuclides-present and future status, Proceedings second international symposium on radiopharmaceuticals March, Seattle, Washington. The Society of Nuclear Medicine Inc., New York. (2) Qaim, S. M. (2004): Use of cyclotron in medicine, Radiation Physics and Chemistry, 71, pp (3) Koning, A.J. Hilaire, S., Duijvestijn, M.C.: TALYS-1.0., Proceedings of the International Conference on Nuclear Data for Science and Technology, April 22-27, 2007, Nice, France.(2008). (4) Herman, M., Capote, R., Sin, M., Trkov, A., Carlson, B.V., Obložinský, P., Mattoon, C.M., Wienke, H., Hoblit, S., Cho, Young-Sik, Plujko, V., Zerkin, V.:EMPIRE-3.1 Rivoli Modular system for nuclear reaction calculations and nuclear data evaluation. (2012). (5) Firestone, R.B. (1998). Table of Isotopes, 8 th edition, John Wiley & Sons, New York, USA. (6) Tanaka, S. and Furukawa, M., Excitation Functions For (P,N) Reactions with Titanium, Vanadium, Chromium, Iron and Nickel Up to 14 MeV, Journal of the Physical Society of Japan Vol.14, p.1269, (1959). (7) Linder B. and James R.A., cross section of nuclear reactions involving nuclear isomers, Phys. Rev. 114,322,(1959) (8) Wing, J. and Huizenga, J.R., (p,n) Cross Sections of V51, Cr, Cu63, Cu65, Ag107, Ag109, Cd111, Cd114, and La139 from 5 to 10.5 MeV, Physical Review Vol.128, p.280, (1962). (9) Skakun, E.A., Batij, V.G., Rakivnenko, Ju.N. and Rastrepin, O.A., Investigation of cross sections of Cr-(p,n)Mn--m,g and Cr-54(p,n)Mn-54 reactions in the energy range from 5 to 9 MeV., 36.Conf.Nucl.Spectrosc.and Nucl.Struct.,Kharkov 1986 p.277, (1986). (10) Burgus, W.H., Cross sections for the reactionsti48(d,2n)v48, Cr(d,2n)Mn and 56 Fe(d,2n) 56 Co. (11) ChengXiaowu, WangZhenxia, WangZhenjie, YangJinqing, Some measurements of deuteron induced excitation function at 13 MeV, Acta Physica Sinica Vol.22, Issue.2, p.250, (12) Cogneau, M. Absolute cross sections and excitation functions for deuteron induced reactions on chromium between 2 and 12 MeV., Nuclear Physics Vol.79, p.203,1966. (13) Nassiff, S.J.and Munzel, H., CROSS SECTIONS FOR THE REACTIONS 66ZN(D,N)67GA, CR(D,2N)G-MN AND 186W(D,2N)186RE., Radiochimica Acta Vol.19, Issue.3, p.97, (14) West, H.I., Lanier, R.G.and Mustafa, M.G. CR-(P,N)MN--G,M AND CR-(D,2N)MN- -G Cross section, Physical Review, Part C, Nuclear Physics Vol.35, p.2067, (15) Dmitriev, P.P., Konstantinov, I.O. and Krasnov, N.N., Methods for producing the Mn- isotope., Soviet Atomic Energy Vol.26, Issue.5, p.467,