Radiochim. Acta 2015; 103(1): 1–6 Naohiko Otuka* and Sandor Takács Definitions of radioisotope thick target yields Abstract: Definitions of thick target yields are reviewed in relation to their documentation for the experimental nuclear reaction data library (database). Researchers reporting experimental thick target yields are urged to define their yields clearly with an appropriate unit in order to compile them in the experimental data library (EXFOR) in a consistent manner, and also to properly utilise them for comparison with other experimental and evaluated yields. Keywords: Thick target yield, Excitation function, Cross section, Radioisotope production, Nuclear data, EXFOR. DOI 10.1515/ract-2013-2234 Received December 4, 2013; accepted July 14, 2014 1 Introduction Experimental thick target yields and excitation functions (i. e., energy dependent isotope production cross sections) are essential for development of large scale high-current medical systems that can produce enhanced yields of radioisotopes [1]. The thick target yields obtained in routine production (practical yields) are usually lower than those measured under well-defined conditions (nominal yields) due to various possible reasons such as loss of the beam particles, variation of the beam intensity, loss of the reaction product (e. g., evaporation, sublimation, recoil effect), or density reduction and radiation damage effects of the target material [1–7]. Nevertheless the measurements of the nominal yields are useful to validate the excitation functions [8]. Measurement of the reaction rates in broad neutron spectra has been recognized as useful validation of the excitation functions of neutron-induced reactions for dosimetry applications, and the excitation function averaged over the well-known 252 Cf spontaneous fission neutron spectrum has been the most standard observable to *Corresponding author: Naohiko Otuka, Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Wagramerstraße 5, A-1400 Wien, Austria, e-mail: [email protected] Sandor Takács: Institute of Nuclear Research, Hungarian Academy of Science, Bem tér 18/c, H-4026 Debrecen, Hungary validate the excitation functions of neutron dosimetry reactions [9, 10]. Similar benchmarking can be performed for charged-particle induced reactions by comparison of the experimental thick target yields and excitation functions. Newly measured excitation functions for charged-particle induced reactions are often reported with the thick target yields obtained by integration of the excitation functions, and compared with directly measured ones in the literature (e. g., [2, 3]). There are also a few experimental works where the thick target yields and excitation functions were measured in parallel (e. g., [8, 11–14]). Experimental excitation functions and thick target yields for charged-particle induced radioisotope production have been compiled in the experimental nuclear reaction data library (EXFOR) [15–22] from more than 800 experimental works by the International Network of Nuclear Reaction Data Centres (NRDC) under the auspices of the International Atomic Energy Agency (IAEA). In order to improve the completeness of EXFOR, the IAEA Nuclear Data Section (NDS) and Hokkaido University Nuclear Reaction Data Centre (JCPRG) have compared experimental works in EXFOR with those in the Landolt-Börnstein compilation [23] for proton, deuteron, triton, helium-3 and alpha induced reactions, and the Data Centres are compiling the articles still missing in EXFOR [15]. In order to retrieve and analyse experimental thick target yields of a specific type from EXFOR efficiently and appropriately, each experimental data set must be properly tagged not only by the reaction (i. e., target, beam particle, product) but also by the definition of the thick target yield. However, the large variety of nomenclature in the literature makes compilation work difficult. There are fewer problems in compilation of the thick target yields of stable reaction products, which are always expressed in terms of the number of the produced nuclei per unit induced electric charge (or per beam particle) irradiating the target. Since the product is stable, the number of produced nuclei is a linear function of the irradiation time, and consequently the thick target yield per unit irradiation time is “irradiation time independent”. Although the thick target yields of radioactive reaction products can be expressed in the same manner, usually other expressions (e. g., activity instead of number of produced nuclei) have been used for practical reasons, and this has become a major source of confusion. Furthermore, the definition of experimental thick target yields is often insufficient or Unauthenticated Download Date | 6/18/17 7:35 PM 2 | N. Otuka and S. Takács, Definition of radioisotope thick target yields even missing in the literature. The amount of a radioactive product is determined by measurement of its activity. The problem arises from the fact that the activity is time dependent, and several time dependent corrections should be applied to the measured activity to determine the proper number of the produced nuclei. The purpose of this paper is to review various thick target yields defined in the EXFOR Compiler’s Manual (LEXFOR [24] under revision), compare with definitions given in earlier reports [25–27], and encourage experimentalists to report their thick target yields in a well-defined manner. 2 Definitions Suppose a sample material having the target isotope number density 𝜌 and thickness 𝐿 is irradiated by beam particles (charge number 𝑍, initial beam energy 𝐸0 , number of beam particles irradiating the sample per unit irradiation time 𝐼0 ¹ ) to produce an isotope of interest. If the cross section to produce the isotope at depth 𝑥 in the sample is 𝜎(𝑥), the total number of the produced nuclei 𝑌(𝑡) during an irradiation time 𝑡 (𝑡 = 0 at the beginning of irradiation) is 𝐿 𝑌(𝑡) = 𝑡 ∫d𝑥 𝐼(𝑥)𝜎(𝑥)(𝜌/𝑍𝑒) (1) 0 𝐸0 ≃ 𝑡𝐼0 ∫d𝐸 (− 𝐸𝐿 ≡ 𝑡𝐼0 𝑦, 1 d𝐸 −1 ) 𝜎(𝐸)/(𝑍𝑒) 𝜌 d𝑥 (2) (3) If the product is radioactive with decay constant 𝜆, the number of the produced nuclei present in the sample 𝑁(𝑡) satisfies d𝑁(𝑡) d𝑌(𝑡) = − 𝜆𝑁(𝑡) = 𝐼0 𝑦 − 𝜆𝑁(𝑡), d𝑡 d𝑡 (4) and its solution is 𝑁(𝑡) = 𝐼0 𝑦 1 − 𝑒−𝜆𝑡 . 𝜆 (5) The activity of the sample material per unit current at 𝑡 is therefore 𝜆𝑁(𝑡) = 𝑦 (1 − 𝑒−𝜆𝑡 ) ≡ 𝑎(𝑡), 𝐼0 (6) which is defined as the end-of-bombardment (EOB) thick target yield in LEXFOR³. For a very long irradiation 𝜆𝑡 ≫ 1 (e. g., irradiation is much longer than the half-life of the product), the production rate and decay rate of the product are in equilibrium, and the EOB thick target yield becomes 𝑎(𝑡 → ∞) = 𝑦 ≡ 𝑎sat , (7) which is defined as the saturation thick target yield in LEXFOR. Equation (7) shows that the thick target product yield 𝑦 and the saturation thick target yield 𝑎sat are essentially the same except for their interpretation: 𝑦 is the number of the produced nuclei per unit induced electric charge (e. g., nuclei/μC), while 𝑎(𝑡) and 𝑎sat are the decay rates of the product per unit current (e. g., MBq/μA). Note that 1 [nuclei/μC] = 1 [MBq/μA]. The curve of the growing yield 𝑎(𝑡) versus irradiation time is not a straight line (See Figure 1 (top)). From Eq. (6), the time evolution (rate) of the activity per unit current is where 𝐸𝐿 is the beam energy at the exit of the sample (or 𝐸𝐿 = 0 if the sample is thicker than the stopping length), −(1/𝜌)(d𝐸/d𝑥) is the stopping power, and 𝑦 is the number of the produced nuclei following deposition of unit induced electric charge. The quantity 𝑦 is defined as the thick target product yield in LEXFOR. It is sometimes also given as the number of the produced nuclei per beam particle instead of per unit induced electric charge. The thick target product yield can be defined for both stable and radioactive products, but is mostly used for stable ones². is defined as the physical thick target yield in LEXFOR. The unit of the physical thick target yield could be MBq/C or MBq/μA⋅h⁴, and this choice will be discussed later. 1 We limit our discussion to irradiation with a constant beam current. 3 “yield” and “activity” of a radioactive product are hereafter related by yield = activity/current [26]. 2 An exception is [28] where thick target product yields of radioactive products are tabulated. 4 Because 𝛼phys is time derivative of 𝑎(𝑡), use of MBq/μA/h is also possible. But this is not commonly used and not recommendable. d𝑎(𝑡) = 𝜆𝑦𝑒−𝜆𝑡 ≡ 𝛼(𝑡). d𝑡 (8) In particular, the rate at the beginning of the irradiation (𝑡 = 0) per unit current 𝛼(𝑡 = 0) = 𝜆𝑦 ≡ 𝛼phys Unauthenticated Download Date | 6/18/17 7:35 PM (9) N. Otuka and S. Takács, Definition of radioisotope thick target yields | 3 Table 1: Thick target yield quantities defined in EXFOR (𝑡 = 0 at the beginning of irradiation). Name (in EXFOR) [24] This paper Symbol [26] thick target product yield§ 𝑦 – – – ,PY„TT/CH nuclei/μC, nuclei/μA⋅h end-of-bombardment thick target yield 𝑎(𝑡) 𝐴/𝐼 𝐻EOB ∗ ,TTY„EOB MBq/μA saturation thick target yield 𝑎sat = 𝑎(𝑡 → ∞) – – 𝐴2 ,TTY„SAT MBq/μA physical thick target yield 𝛼phys = 𝛼(𝑡 = 0) 𝐵 𝑌EOIB† 𝑌 ,TTY„PHY‡ MBq/C¶ , MBq/μA⋅h [25] Typical unit [27] EXFOR § Usually used for stable products. 𝑎(𝑡 = 1 h) is defined as 𝐴 1 in [27]. † EOIB = End of an instantaneous bombardment. ‡ (PHY) is used instead of PHY when the compiler is uncertain if the physical thick target yield is given. ¶ Recommended. 1 MBq/C = 0.0036 MBq/μA⋅h. ∗ 25 TTY (GBq/μA) 20 αphys⋅t 15 10 asat=a(t→∞) dTTY/dt (GBq/μA⋅h) 5 a(t) 0 2.5 αphys 2 1.5 α(t)=da(t)/dt 1 0.5 0 0 1 2 3 4 5 Irradiation time t (hour) 6 7 8 Fig. 1: Time dependence of the production thick target yield 𝑎(𝑡) and its rate 𝛼(𝑡) for 18 O(p,n)18 F(𝑇1/2 = 110 min) at 𝐸0 = 10.0 MeV based on 𝑎sat = 6.630 GBq/μA, 𝛼phys = 697.5 GBq/C≃2.5 GBq/μA⋅h [27]. TTY = thick target yield. From Eqs. (6), (7) and (9) the three quantities 𝑎(𝑡), 𝑎sat and 𝛼phys are related by 𝑎(𝑡) = 𝑎sat (1 − 𝑒−𝜆𝑡 ) = 𝛼phys (1 − 𝑒−𝜆𝑡 ) /𝜆. (10) Note that 𝛼phys is the time derivative of 𝑎(𝑡) at 𝑡 = 0, and its dimension is different from 𝑎(𝑡) and 𝑎sat although they all are named “yields”⁵. Table 1 lists the four yields defined above with their notations in [25– 5 An alternative term “thick target production rate” used by G. F. Steyn, S. J. Mills et al. [11] clearly indicates that the quantity 𝛼phys is time derivative (rate) of the time dependent yield. 27] as well as typical units. A numerical example is also shown in Figure 1 for the 18 O(p,n)18 F(𝑇1/2 = 110 min) reaction at 𝐸0 = 10.0 MeV (𝑎sat = 6.630 GBq/μA, 𝛼phys = 697.5 GBq/C ≃ 2.5 GBq/μA⋅h [27]). Table 2 summarizes the conversion coefficients (multipliers) connecting these yields. This table shows that one may convert from one expression to another very easily. As long as the definition chosen by the experimentalists is clearly described, they have freedom to report their experimental yields by any of these expressions. Note that the physical thick target yield is most suitable for comparison of the directly measured yields with yields derived from excitation functions. In addition to the definition of the reported yields, some key parameters for irradiation conditions (e. g., beam Unauthenticated Download Date | 6/18/17 7:35 PM 4 | N. Otuka and S. Takács, Definition of radioisotope thick target yields Table 2: Conversion coefficient (multiplier) between different types of yields. The first column and first row give the input and output, e. g., 𝑎(𝑡) = 𝑎sat (1 − 𝑒−𝜆𝑡 ) = 𝛼phys (1 − 𝑒−𝜆𝑡 )/𝜆. 𝑎(𝑡) 𝑎(𝑡) 𝑎sat = 𝑦 𝛼phys 1 1/(1 − 𝑒−𝜆𝑡 ) 𝜆/(1 − 𝑒−𝜆𝑡 ) 𝑎sat = 𝑦 (1 − 𝑒 1 𝜆 −𝜆𝑡 𝛼phys ) (1 − 𝑒−𝜆𝑡 )/𝜆 1/𝜆 1 energy range, beam intensity, irradiation time, target thickness and composition) must be described. For example, the EOB thick target yield is not well-defined if the irradiation time (e. g., “1-hour irradiation”) is not specified. 3 Linear approximation for irradiation time The activity for 1 hour-1μA irradiation (𝐴 1 in [27]) is often extrapolated to higher beam intensity or longer irradiation time. Since the activity is exactly proportional to the beam intensity, linear extrapolation to higher beam intensity does not introduce any error. On the other hand one should be more careful in extrapolation of the activity to longer irradiation time since the activity in general is not a linear function of the irradiation time. Figure 1 (top) shows that the physical thick target yield 𝛼phys gives the slope of the growing curve 𝑎(𝑡) at the beginning of irradiation [26]. If the half-life of the product 𝑇1/2 = ln 2/𝜆 is long compared to the irradiation time (i. e., 𝜆𝑡 ≪ 1), the EOB thick target yield 𝑎(𝑡) in Eq. (10) can be approximated by a linear function of the irradiation time 𝑡: 𝜆𝑡≪1 𝑎(𝑡) = 𝛼phys (1 − 𝑒−𝜆𝑡 ) /𝜆 ≃ 𝛼phys 𝑡, (11) which gives a formula for derivation of the physical thick target yield, 𝜆𝑡≪1 𝛼phys = 𝑎(𝑡)𝜆/ (1 − 𝑒−𝜆𝑡 ) ≃ 𝑎(𝑡)/𝑡. (12) This approximation (linear approximation) has been often applied incorrectly for short-lived isotopes not satisfying 𝜆𝑡 ≪ 1. A similar inappropriate approximation is also seen for derivation of the 1-hour EOB yield from the 𝑡-hour EOB yield by 𝑎(𝑡 = 1 h) ≃ 𝑎(𝑡)/𝑡. Table 3 shows such an example seen in two articles published in 2011 [29, 30]. The corresponding author of these articles later explained that the reported yields were obtained by 𝑎(𝑡)/𝑡 with 𝑡 in hour. Fortunately the irradia- Table 3: Half-life 𝑇1/2 , irradiation time 𝑡, their ratio as well as correction factors for conversion of the thick target yields in [29, 30] to the corresponding physical thick target yields (𝐶1 ) and 1-hour end-of-bombardment (EOB) thick target yield (𝐶2 ). Products 97 Ru Tc 95 Tc 93 Mo 149 Tb 150 Tb 151 Tb 149 Gd 96 𝑇1/2 (h) 𝑡 (h) 𝑇1/2 /𝑡 𝐶1 𝐶2 67.9 102.7 20.0 6.9 4.1 3.5 17.6 9.3 6 6 6 6 9.3 9.3 9.3 9.3 11.3 17.1 3.3 1.2 0.4 0.4 1.9 1.0 1.03 1.02 1.11 1.33 1.98 2.19 1.19 1.39 1.03 1.02 1.09 1.27 1.83 1.99 1.17 1.34 tion time is well documented in the articles, and therefore we can convert their yields to the corresponding physical and 1-hour EOB thick target yields by applying the correction factors 𝐶1 = 𝑡𝜆/(1−𝑒−𝜆𝑡 ) and 𝐶2 = 𝑡(1−𝑒−𝜆 )/(1−𝑒−𝜆𝑡 ), respectively, which are not close to unity for short-lived products. 4 Units of thick target yields Not only experimentalists who extrapolate the 1-hour EOB thick target yield 𝑎(𝑡 = 1 h) from the measured 𝑡-hour EOB thick target yield 𝑎(𝑡) by 𝑎(𝑡)/𝑡, but also those who properly extrapolate the 1-hour EOB thick target yield by applying the factor 𝑎(𝑡 = 1 h)/𝑎(𝑡) = (1−e−𝜆 )/(1−e−𝜆𝑡 ) often report their 1-hour EOB thick target yield in MBq/μA⋅h interpreting that “h” means “1-hour irradiation”. On the other hand, people who understand the usage of various units as summarized in Table 1 are confused when they find a yield in MBq/μA⋅h is reported with timing information (e. g., “1hour irradiation”). The best way to avoid all such confusions is to use MBq/μA for the EOB and saturation thick target yields while to use MBq/C (not MBq/μA⋅h) for the physical thick target yields. When the experimentalists feel that the physical thick target yields in MBq/μA⋅h are convenient for a practical reason, the physical thick target yields in this unit can be additionally reported. 5 Conclusion The final goal of compilation of experimental thick target yields is to provide access to all available measured yields to researchers, and help to improve radioisotope production technology based on an intercomparison of the existUnauthenticated Download Date | 6/18/17 7:35 PM N. Otuka and S. Takács, Definition of radioisotope thick target yields ing experimental and evaluated data. In order to achieve this goal, experimentalists reporting thick target yields are strongly recommended to – provide the definition of the reported thick target yield very clearly; – report physical thick target yield in MBq/C (and additionally in MBq/μA⋅h if necessary), while EOB and saturation thick target yields in MBq/μA; – report EOB thick target yield always with the irradiation time because the quantity is irradiation time dependent; – provide the key irradiation parameters (e. g., beam energy range, beam intensity, irradiation time, target thickness and composition); – provide the decay data (e. g., gamma intensity) and uncertainties adopted in the derivation of the reported yields with their references; – do not apply the linear approximation to derive the physical and 1-hour EOB thick target yields from the EOB thick target yield. Acknowledgement: We would like to thank Prof. S. M. Qaim (Forschungszentrum Jülich, Germany) and Dr. G. F. Steyn (iThemba LABS, South Africa) as well as the reviewers for careful reading of our manuscript and for the detailed comments on it. We are indebted to Dr. R. A. Forrest (IAEA NDS) for a careful reading of the manuscript and also for Dr. M. Maiti (Saha Institute of Nuclear Physics, India) for clarifying the definition of the yields published in [29, 30]. We are also grateful for contributions from IAEA Member States to organize the international collaboration on the EXFOR library development. References 1. Qaim, S. M.: Nuclear data relevant to cyclotron produced shortlived medical radioisotopes. Radiochim. Acta 30, 147 (1982). 2. Dmitriev, P. P., Molin, G. A.: Radionuclide yields for thick targets at 22 MeV proton energy. Report INDC(CCP)-188. International Atomic Energy Agency (1982). EXFOR A0168. 3. Dmitriev, P. P., Krasnov, N. N., Molin, G. A.: Yields of radioactive nuclides formed by bombardment of a thick target with 22-MeV deuterons. Report INDC(CCP)-210. International Atomic Energy Agency (1983). EXFOR A0194. 4. Michael, H., Rosezin, H., Apelt, H., Blessing, G., Knieper, J., Qaim, S. M.: Some technical improvements in the production of 123 I via the 124 Te(p,2n)123 I reaction at a compact cyclotron. Int. J. Appl. Radiat. Isot. 32, 581 (1981). EXFOR R0006. 5. Qaim, S. M.: Recent developments in the production of 18 F, 75,76,77 Br and 123 I. Appl. Radiat. Isot. 37, 803 (1986). | 5 6. Qaim, S. M.: Target development for medical radioisotope production at a cyclotron. Nucl. Instrum. Meth. Phys. Res. A 282, 289 (1989). 7. Qaim, S. M.: Decay data and production yields of some nonstandard positron emitters used in PET. Q. J. Nucl. Med. Mol. Imaging 52, 111 (2008). 8. Qaim, S. M., Steyn, G. F., Spahn, I., Spellerberg, S., van der Walt, T. N., Coenen, H. H.: Yield and purity of 82 Sr produced via the nat Rb(p,xn)82 Sr process. Appl. Radiat. Isot. 65, 247 (2007). EXFOR O2135. 9. Bersillon, O., Greenwood, L. R., Griffin, P. J., Mannhart, W., McLaughlin, P. K., Nolthenius, H. J., Nouri, A., PaviottiCorcuera, R., Shibata, K., Trkov, A., Zolotarev, K. I., Zsolnay, E. M.: International Reactor Dosimetry File 2002 (IRDF2002), IAEA Technical Report Series STI/DOC/010/452, International Atomic Energy Agency (2006) and references therein. 10. Capote, R., Zolotarev, K. I., Pronyaev, V. G., Trkov, A.: Updating and extending the IRDF-2002 dosimetry library. J. ASTM Internat. 9, JAI104119 (2012). 11. Steyn, G. F., Mills, S. J., Nortier, F. M., Simpson, B. R. S., Meyer, B. R.: Production of 52 Fe via proton-induced reactions on manganese and nickel. Appl. Radiat. Isot. 41, 315 (1990). EXFOR A0497. 12. Kastleiner, S., Qaim, S. M., Nortier, F. M., Blessing G., van der Walt, T. N., Coenen, H. H.: Excitation functions of 85 Rb(p,xn)85m,g,83,82,81 Sr reactions up to 100 MeV: integral tests of cross section data, comparison of production routes of 83 Sr and thick target yield of 82 Sr. Appl. Radiat. Isot. 56, 685 (2002). EXFOR D4127. 13. Steyn, G. F., Vermeulen, C., Szélecsényi, F., Kovács, Z., Suzuki, K., Fukumura, T., Nagatsu, K.: Excitation functions of proton induced reactions on 89 Y and 93 Nb with emphasis on the production of selected radio-zirconiums. J.Korean Phys. Soc. 59, 1991 (2011). EXFOR D0629. 14. Amjed, N., Tárkányi, F., Ditrói, F., Takács, S., Yuki, H.: Activation cross-sections of deuteron induced reaction of natural Ni up to 40 MeV. Appl. Radiat. Isot. 82, 87 (2013). EXFOR D4288. 15. Otuka, N., Dupont, E., Semkova, V., Pritychenko, B., Blokhin, A. I., Aikawa, M., Babykina, S., Bossant, M., Chen, G., Dunaeva, S., Forrest, R. A., Fukahori, T., Furutachi, N., Ganesan, S., Ge, Z., Gritzay, O. O., Herman, M., Hlavač, S., Katō, K., Lalremruata, B., Lee, Y. O., Makinaga, A., Matsumoto, K., Mikhaylyukova, M., Pikulina, G., Pronyaev, V. G., Saxena, A., Schwerer, O., Simakov, S. P., Soppera, N., Suzuki, R., Takács, S., Tao, X., Taova, S., Tárkányi,F., Varlamov, V. V., Wang, J., Yang, S. C., Zerkin, V., Zhuang, Y.: Towards a more complete and accurate experimental nuclear reaction data library (EXFOR): International collaboration between Nuclear Reaction Data Centres (NRDC). Nucl. Data Sheets 120, 272 (2014). 16. Otuka, N., Dunaeva, S., Dupont, E., Schwerer, O., Blokhin, A.: The role of the Nuclear Reaction Data Centres in experimental nuclear data knowledge sharing. J.Korean Phys. Soc. 59, 1292 (2011). 17. Henriksson, H., Schwerer, O., Rochman, D., Mikhaylyukova, M. V., Otuka, N.: The art of collecting experimental data internationally: EXFOR, CINDA and the NRDC Network. Proceedings of the International Conference on Nuclear Data for Science and Technology (ND2007), Nice, 2007, EDP Sciences, Les Ulis, 2008, p737. Unauthenticated Download Date | 6/18/17 7:35 PM 6 | N. Otuka and S. Takács, Definition of radioisotope thick target yields 18. Schwerer, O., McLane, V., Henriksson, H., Maev, S.: Nuclear Reaction Data Centre Network: A success story. AIP Conf. Proc. 763, 83 (2005). 19. McLane, V., Kellett, M., Schwerer, O., Maev, S.: Nuclear Reaction Data Center Network: Past, present, and future. J. Nucl. Sci. Technol. Suppl. 2, 1458 (2002). 20. Nordborg, C., McLane, V., Schwerer, O., Manokhin, V. N.: The Nuclear Data Centers Network. Proceedings of the International Conference on Nuclear Data for Science and Technology, Trieste, 1997, Societá Italiana di Fisica, Bologna, 1997, p1069. 21. Lemmel, H. D., Manokhin V. N., McLane, V., Webster, S.: The Network of the Nuclear Reaction Data Centres. Proceedings of the International Conference on Nuclear Data for Science and Technology, Jülich, 1991, Springer Verlag, Heidelberg, 1992, p811. 22. McLane, V., Nordborg, C., Lemmel, H. D., Manokhin V. N.: Nuclear Reaction Data Centers. Proceedings of the International Conference on Nuclear Data for Science and Technology, Mito, 1988, Japan Atomic Energy Research Institute, 1988, p1157. 23. Schopper, H. (ed.): Production of radionucliedes at intermediate energies. Landolt-Börnstein New Series Group I Subvolume A,B,C,D,F,G,H and I., Springer-Verlag Berlin Heidelberg, 1991– 1999. 24. Otsuka, N.(ed.): LEXFOR (EXFOR Compiler’s Manual). Report IAEA-NDS-208 (Rev.2011/01), International Atomic Energy Agency (2011). 25. Dmitriev, P. P.: Radionuclide yield in reactions with protons, deuterons, alpha particles and helium 3. Report INDC(CCP)263. International Atomic Energy Agency (1986). 26. Bonardi, M.: The contribution to nuclear data for biomedical radioisotope production from the Milan Cyclotron Laboratory. Report INDC(NDS)-195, p98. International Atomic Energy Agency (1988). 27. Gul, K., Hermanne, A., Mustafa, M. G., Nortier, F. M., Oboložinský, P., Qaim, S. M., Scholten, B., Shubin, Y., Takács, S., Tárkányi, F. T., Zhuang, Y. X.: Charged particle cross-section database for medical radioisotope production: diagnostic radioisotopes and monitor reactions. Report IAEA-TECDOC-1211. International Atomic Energy Agency (2001). 28. Dmitriev, P. P.: Systematics of nuclear reaction yields for a thick target bombarded with 22 MeV protons. Report INDC(CCP)-222, p23. International Atomic Energy Agency (1984). EXFOR A0195. 29. Maiti, M., Lahiri, S.: Production and separation of 97 Ru from 7 Li activated natural niobium. Radiochim. Acta 99, 359 (2011). 30. Maiti, M., Lahiri, S., Tomar, B. S.: Investigation on the production and isolation of 149,150,151 Tb from 12 C irradiated natural praseodymium target. Radiochim. Acta 99, 527 (2011). Unauthenticated Download Date | 6/18/17 7:35 PM
© Copyright 2026 Paperzz