Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 Contents lists available at SciVerse ScienceDirect Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb Excitation functions of (d,x) nuclear reactions on natural titanium up to 24 MeV Mayeen Uddin Khandaker a,⇑, Hiromitsu Haba b, Jumpei Kanaya b, Naohiko Otuka c a Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia Nishina Center for Accelerator-based Science, RIKEN, Wako, Saitama 351-0198, Japan c Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna, Austria b a r t i c l e i n f o Article history: Received 23 October 2012 Received in revised form 29 November 2012 Available online 20 December 2012 Keywords: Excitation functions nat Ti(d,x) reactions 24-MeV deuteron Thick target yields TALYS calculations Deuteron-induced cross-section database a b s t r a c t Excitation functions of the natTi(d,x)48V and natTi(d,x)43,44m,44g,46,47,48Sc nuclear reactions were measured up to a 24-MeV deuteron energy by using a stacked-foil activation technique combined with c-ray spectrometry with a high-purity germanium detector at the AVF cyclotron of the RIKEN RI Beam Factory, Wako, Japan. An overall good agreement is found between the measured cross-sections and the literature ones, whereas partial agreements are obtained for the theoretical calculations based on the TALYS code. Physical thick target yields, i.e., induced radioactivities per unit fluence of the 24-MeV deuteron were also deduced, and they were compared with the directly measured ones in the literature. The present results will have an important role in enrichment of the literature database of the deuteron-induced reactions on natural titanium leading to various applications. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Light-charged-particle-induced production cross-sections of residual radionuclides from various targets find remarkable attention to the nuclear data community due to their increasing applications in nuclear medicine, accelerator and nuclear technology, and testing of nuclear reaction theories. Availability of variable energy cyclotrons throughout the world made it possible to measure cross-sections via light-charged-particle irradiations on different elements. In reality, optimum production parameters of a particular radionuclide leading to practical applications could be determined only if cross-sections via different induced channels like proton, deuteron, and alpha are sufficient in the literature. However, measured cross-sections of the (d,x) processes for different elements are scanty relative to (p,x). Owing to this fact, we initiated systematic studies to report new experimental cross-sections via deuteron irradiations on different elements relevant to various practical applications. In this work, we measured excitation functions for the natTi(d,x)48V and natTi(d,x)43,44m,44g,46,47,48Sc reactions up to a 24-MeV deuteron energy using the AVF cyclotron of the RIKEN RI Beam Factory (RIBF), Wako, Japan. Titanium (Ti), a high-strength, lustrous, durable, and light white metal finds wide applications in industrial, aerospace, recreational, and emerging markets. It is widely used as a refractory and corrosion resistant metal. Due to its non-toxicity and biocompatibility, titanium and its alloys such as Ti-6Al-4V are useful in a wide range ⇑ Corresponding author. Tel.: +60 1115402880; fax: +60 379674146. E-mail address: [email protected] (M.U. Khandaker). 0168-583X/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.nimb.2012.12.003 of structural, chemical, petrochemical, marine, and biomaterial applications. Moreover, titanium is a potential target material for the production of medical radionuclides such as 43Sc, 44gSc, 46Sc, and 47Sc. The suitable decay properties of 43Sc (T1/2 = 3.891 h; total Ec = 372.9 keV, Ic = 22.5%; Emax bþ = 1198.8 keV, Ibþ = 88.1%) made it promising to be used in vivo dosimetry [1]. 44gSc (T1/2 = 3.97 h; total Emax bþ = 1473.5 keV, I bþ = 94.27%; Ec = 1157.02 keV, Ic = 99.9%) is one of the most interesting radionuclide for nuclear medical imaging using a b+-c coincidence technique [2]. Moreover, both 43Sc and 44g Sc find applications as PET surrogates for the therapeutic isotope 47 Sc and possibly for 177Lu [3]. 47Sc (T1/2 = 3.3492 d) shows a promising interest in radio-immunotheraphy [4] due to its favorable b emission (Emax = 440.9 keV, Ib1 = 68.4%; Emax = 600.3 keV, b b 1 2 47 Ib2 = 31.6%). Sc could be also used in an imaging procedure due to its primary c-ray of 159.381 keV (Ic = 68.3%). The long-lived 46 Sc (T1/2 = 83.79 d) was applied as a labeled microsphere for investigation of myocardial blood flow measurements [5]. 46Sc was also successfully applied as a radiotracer to analyze lungs by Wehner et al. [6]. Furthermore, Inoue and Komura [7] demonstrated the potential use of 46Sc as a cosmogenic radionuclide for an investigation of the evolution history of chondrites after separation from their parent body. In addition to the wide use of the natTi(d,x)48V reaction in monitoring of beam intensity and energy [8–10], 48V was investigated as an alternative of 68Ga to use as a calibration source for PET cameras [11]. 48V is also a well-known radiotracer in many research areas from biology [12,13] to material science [14,15]. 48V was used as a thermoluminescence dosimetry source for intravascular brachytherapy (IVBT) due to its relatively ease production scheme, a minimum of 30-days shelf-life, and 15 M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 2. Experimental The irradiation technique, the radioactivity determination, and the data evaluation procedures were similar to our previous works [27–32]. A well established stacked-foil activation technique combined with c-ray spectrometry with a high-purity germanium (HPGe) detector was employed to determine production cross-sections of residual radionuclides by irradiating deuterons on titanium metallic foils. 2.1. Targets and irradiations A titanium foil (99.5% purity; 20 lm thickness; Nilaco Corp., Japan; Lot no.: 453212) having natural isotopic compositions (46Ti 8.25%, 47Ti 7.44%, 48Ti 73.72%, 49Ti 5.41%, and 50Ti 5.18% [33]) was used as the target material. Several foils of aluminum (>99% purity; 100 lm thickness; Nilaco Corp., Japan; Lot no.: 013323) and natural iron (99.995% purity; 22 lm thickness; Rare Metallic Co. Ltd., Japan; Lot no.: 60530-83-MI-R) were inserted in between any two consecutive Ti foils throughout the whole stack. The Al foil was used to cross-check the beam intensity determined from the front positioned Ti foil. The Al and Fe foils were also used to degrade the beam energy throughout the whole stack. The irradiation was carried out in a standard target holder that served as a Faraday cup: the number of incident deuterons was estimated from the collected charge with the Faraday cup. The stacked-foils were irradiated for 2.0 h with a 24-MeV deuteron beam from the AVF cyclotron with an average beam current of 215 nA. The beam was collimated to 9-mm diameter. All of the monitor and target foils were prepared with a size of 15 15 mm2 to ensure that equal areas of the monitors and targets received the same beam line. 2.2. Measurement of the radioactivity After the irradiation, the samples were removed from the target holder, and the activities of the produced radionuclides were measured using a high resolution c-ray spectrometer (1.85 keV at FWHM at 1332.5 keV). The c-ray spectrometer was a p-type coaxial HPGe detector (ORTEC; GEM-25185P; Serial no. 33-TP10928B; 55.1-mm crystal diameter and 52.0-mm thickness; operating voltage: +2000 V) having an efficiency of 25% relative to a NaI(Tl) detector of 7.62 cm diameter 7.62 cm thickness. The HPGe detector was coupled to a 4096 multi-channel analyzer with the associated electronics to determine the photopeak area of the c-ray spectra. The spectrum analysis was done using a Gamma Vision 5.0 (EG&G ORTEC) computer program. The photopeak efficiency curve of the Ge detector was determined with a multi-nuclide point source having the specifications of the following radionuclides: 241Am (59.541 keV), 109Cd (88.040 keV), 57Co (122.061 keV; 136.474 keV), 139Ce (165.8575 keV), 203Hg (279.1952 keV), 113Sn (391.698 keV), 85Sr (514.007 keV), 137Cs (661.657 keV), 88Y 60 (898.042 keV; 1836.063 keV), and Co (1173.228 keV; 1332.492 keV). As shown in Fig. 1, the detection efficiencies as a function of the photon energy were determined at the counting distances of 2–35 cm from the end-cap of the detector to avoid coincidence losses, to assure a low dead time (<10%), and a point like geometry. The measured detection efficiencies were fitted by using a polynomial function: ln e ¼ 5 X ak ln ðEk Þ k¼0 where e is the detection efficiency, ak represents the fitting parameters, and E is the energy of the photopeak. The fitting parameters such as a0 to ak are presented in Table 1. The activity measurements of the irradiated samples were started about 4 h after the end of bombardment (EOB) to separate the complex c lines from the decay of the undesired short-lived nuclides. The measurements of the irradiated samples were repeated 5–6 times to follow the decay of the radionuclides and thereby to identify the possible interfering nuclides. 2.3. Data analysis The IAEA recommended monitor reactions of 27Al(d,x)24Na (Ed = 22.9 MeV, r = 57.84 mb) and natTi(d,x)48V (Ed = 23.44 MeV, r = 225.5 mb) [10,34] were used to determine the beam intensity. 100 Detection Efficiency (%) the mixed b+ and c emissions mechanism [16]. Arbabi et al. [17] demonstrated the suitability of usefulness of 48V stent in renal artery brachytherapy. Due to its biochemical action in the body (e.g., insulin-like and anti-carcinogenic characteristics, and interaction with ATP-ases), 48V was applied as a labeled compound for in vivo studies [18]. Besides the aforementioned medical applications, 48V was utilized as a positron source to determine the Doppler broadening of 511-keV peak for different materials like copper, lead, and indium at the U-120 cyclotron installations [19], and was also suggested to use in an activation analysis of steel [8]. An accurate determination of production cross-sections for natTi(d,x)48V and natTi(d,x)43,44m,44g,46,47,48Sc, therefore, shows great importances in various practical applications. A detailed survey of literatures reveals that various production pathways have been investigated for the radionuclides of interest in this work: e.g., 43Sc from 42Ca(p,c), 43Ca(p,n), 44Ca(p,2n), 42 Ca(d,n), and 46Ti(p,a); 44Sc from 44Ca(p,n), 41K(a,n), V,Ti(p,spall), and 44Ti decay/generator; 47Sc from 48Ti(c,p), 47Ti(n,p), 50Ti(p,a), nat V(d,x), 45Sc(t,p), and 48Ti(t,a); 48Sc from 48Ca(p,n), 51V(n,a), and 50 Ti(d,a); 48V from 47Ti(p,c) and 45Sc(a,n). However, only a few investigations were carried out for the (d,x) processes using natural or enriched Ti targets [8–10,14,20–25], and considerable discrepancies were found among the reported cross-sections. Therefore, the objective of the present study was to report new cross-sections for the natTi(d,x)48V and natTi(d,x)43,44m,44g,46,47,48Sc reactions to reduce the discrepancies among the literature data and to validate the IAEA recommended cross-sections of the nat Ti(d,x)48V monitor reaction. The measured new cross-sections also find significance in practical applications such as the productions of medical radionuclides, accelerator and target technology to produce high energy or high intensity neutron fluxes for nuclear waste transmutation, RI beam production with neutrons, fusion energy application, and space applications [26]. d= 2 cm; d= 12 cm; 10 d= 7 cm d=24 cm d=35 cm 1 0.1 0.01 1E-3 40 100 1000 2000 Photon Energy (keV) Fig. 1. Detection efficiency of the HPGe detector as a function of photon energy measured at different distances between the sample and the detector surface. 16 M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 Table 1 Coefficients of efficiency fitting curves for different source to detector distances. Source to detector distance (cm) 2 7 12 24 35 Efficiency curves fitting coefficients A0 A1 A2 A3 A4 A5 6.960668E+02 5.158505E+02 5.440220E+02 5.225504E+02 5.575685E+02 5.681181E+02 4.097168E+02 4.339063E+02 4.136920E+02 4.414771E+02 1.850238E+02 1.304289E+02 1.389568E+02 1.318505E+02 1.406984E+02 2.998082E+01 2.067239E+01 2.216439E+01 2.092522E+01 2.230375E+01 2.420308E+00 1.634519E+00 1.763862E+00 1.656513E+00 1.761378E+00 7.785421E02 5.156582E02 5.600938E02 5.231302E02 5.542251E02 Table 2 Decay data and contributing processes of the investigated radionuclides; italicized gamma lines were not used in activity determination. Only the major contributing reactions are listed here. Produced nuclei Half-life, T1/2 Decay mode (%) c-ray energy, Ec (keV) c-ray intensity, Ic (%) Contributing reactions Q-value (MeV) Threshold (MeV) 48 15.9735 d EC (50.1); b+ (49.9) 7.87 99.98 98.2 22.5 47 4.6 7.02 15.16 5.29 14.18 4.4 19.4 23.9 4.5 16.1 4.40 19.4 23.9 4.48 16.10 3.8 12.7 3.97 19.9 4.2 15.1 0.0 7.3 15.8 5.5 17.8 0.0 20.3 24.9 4.6 16.8 0.0 20.3 24.9 4.6 16.8 3.9 13.2 0.0 20.7 4.3 15.7 2.0 13.7 6.5 21.8 4.5 5.4 13.6 3.8 20.1 2.1 14.2 0.0 22.7 4.6 5.6 14.1 0.0 20.9 V 3.891 h EC (11.9); b+ (88.1) 944.13 983.525 1312.106 372.9 Sc 58.61 h EC (1.20); IT (98.8) 271.241 86.7 44g Sc 3.97 h EC (5.73); b+ (94.27) 1157.020 99.9 46g Sc 83.79 d b (1 0 0) 889.277 1120.545 99.9840 99.9870 47 3.3492 d b (1 0 0) 159.381 68.3 48 43.67 h b (1 0 0) 175.361 983.526 1037.522 1312.120 7.48 100.1 97.6 100.1 43 Sc 44m Sc Sc Specifically, the natTi(d,x)48V reaction was used to obtain the final beam current whereas the 27Al(d,x)24Na reaction was used for the purpose of cross checking. We found an excellent agreement in the beam currents determined by the monitor reactions and obtained from the digital current integrator module (ORTEC 439) coupled to the Faraday cup. The deuteron energy degradation along the stacked foils was calculated by using a computer program SRIM-2003 [35]. The use of multiple monitor foils decreases unknown systematic uncertainties during an activity determination. The beam intensity was considered as constant to deduce cross-sections for each foil in the stack. Further, the natFe(d,x)56Co reaction was utilized to monitor the energy scale throughout the whole stack. The cross-sections for the natTi(d,x) processes were determined in the deuteron energy range of 2–24 MeV using a well-known activation formula [28,29]. The decay data such as half-life (T1/2 = ln2/k), c-ray energy (Ec), and c-ray emission probability (Ic) used in the cross-section determination were taken from the ENSDF evaluation [33,36–40] obtained from the NuDat-2.6 software [41], and they are summarized in Table 2. The Q-values and threshold energies calculated on the basis of the atomic mass Ti(d,n) Ti(d,2n) Ti(d,3n) 46 Ti(d,n + a) 47 Ti(d,2n + a) 46 Ti(d,a) 46 Ti(d,2d) 46 Ti(d,2n + 2p) 47 Ti(d,n + a) 48 Ti(d,2n + a) 46 Ti(d,a) 46 Ti(d,2d) 46 Ti(d,2n + 2p) 47 Ti(d,n + a) 48 Ti(d,2n + a) 46 Ti(d,2p) 47 Ti(d,n + 2p) 48 Ti(d,a) 48 Ti(d,2d) 49 Ti(d,n + a) 50 Ti(d,2n + a) IT (100%) decay of 47 Ti(d,2p) 48 Ti(d,2p + n) 49 Ti(d,a) 49 Ti(d,2n + 2p) 50 Ti(d,n + a) 48 Ti(d,2p) 49 Ti(d,n + 2p) 50 Ti(d,a) 50 Ti(d,2d) 48 49 46m Sc evaluation by Audi and Wapstra [42] and the Q-tool system [43] are also presented in Table 2. Intense and independent characteristic c-lines were used to quantify the radionuclides. In some cases, two or more characteristic c-rays were used to cross-check the obtained results. The uncertainty of the deuteron energy for each representing energy point in the stack depends on the irradiation circumstances and the position of the foil in the stack. These are due to the initial beam energy uncertainty (<1%), the target thickness and homogeneity, and the beam straggling. The estimated uncertainties of a representing energy point in the excitation function range from ±0.4 MeV to ±0.8 MeV, which are shown in tables and figures. In this measurement, uncertainties due to c-ray countings were 0.5–8%. In addition, the following uncertainties were assumed or considered: uncertainties due to determination of the beam flux (5%), detector efficiency (4%), sample thickness (1%), and cray intensity (1%). All these uncertainties were considered as independent, and consequently, they were quadratically added according to the laws of error propagation to obtain the total uncertainties. The overall uncertainties of the measured cross-sections were then in the range of 6.5–10.4%. 17 M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 3. Model calculations 10 nat Cross Section (mb) 8 43 Ti(d,x) Sc 6 4 Takacs et al., '97 (Norm.) This work Talys-1.4 (TENDL-2011) 2 0 8 10 12 14 16 18 20 22 24 Deuteron Energy (MeV) Fig. 3. Excitation function for the nat 26 28 30 Ti(d,x)43Sc nuclear reactions. 8 Cross Section (mb) A number of model code systems such as ALICE-IPPE [44], TALYS [45], and EMPIRE [46] for calculating charged-particle-induced reaction cross-sections were developed by the nuclear data community in the recent time. However, there are some difficulties to predict deuteron-induced reaction cross sections by means of conventional reaction models [47,48]: first, the weak binding energy of the deuteron makes a variety in reaction channels such as elastic A(d,n + p)Ag.s. and inelastic A(d,n)B⁄ ? x + C or A(d,p)B⁄ ? x + C break-up reactions as well as stripping (d,p) and (d,n) reactions. Second, currently there is no global deuteron optical potential which can reproduce a wide range of target nuclei and incident deuteron energies [48]. Under this situation, Avrigeanu and Avrigeanu [48] performed a detailed analysis for experimental d + 27Al [49] and d + 63,65Cu [50] activation cross sections. It has been known that experimental (d,p) reaction cross sections are often underestimated by the reaction models [47,48]. To resolve this difficulties, Ignatyuk et al. [51,52] determined an energy dependent phenomenological enhancement factor K based on the general relations for nuclear transfer reaction in the continuum [53] and introduced the factors to the ALICE-IPPE, GNASH [54] and EMPIRE model code systems. Under this situation, it is also meaningful to compare experimental data with model calculation without any adjustment of model parameters so that we may reveal the deficiencies of various reaction mechanisms in conventional reaction models. In this work, therefore, we compare our experimental production crosssections with the TENDL-2011 library [55] which compile production cross-sections based on the nuclear model code TALYS [45] Ver. 1.4. Note that there is no production cross-section where the (d,p) or (d,n) stripping reaction is expected to be dominant among reactions discussed in this article. Takacs et al., '97 (Norm.) Hermanne et al., '00 Takacs et al., '07 Gagnon et al., '10 This work Talys-1.4 (TENDL-2011) 6 4 nat 2 44m Ti(d,x) Sc 2 8 0 0 4 6 10 12 14 16 18 20 22 24 26 28 30 Deuteron Energy (MeV) Fig. 4. Excitation function for the 10 nat nat Ti(d,x)44mSc nuclear reactions. 44g Ti(d,x) Sc work, the cross-sections for the natTi(d,x)48V,43,44m,44g,46,47,48Sc reactions were measured via a deuteron irradiation on the natural titanium targets in the 2–24 MeV energy region. The excitation functions of the investigated radionuclides 48 V and 43,44m,44g,46,47,48Sc are shown in Figs. 2–8 together with the experimental data available in the EXFOR database [56], and also with the predicted data compiled in the TENDL-2011 library by the TALYS code. The numerical data with statistical and other errors are presented in Table 3. Thick target yields were also deduced using the measured cross-sections by taking into account that the total energy is absorbed in the target, and they are shown in Figs. 9 and 10. this 4 Takacs et al., '97 (Norm.) Gagnon et al., '10 This work Talys-1.4 (TENDL-2011) 2 0 2 nat Jung '91 West et al., '93 (Norm.) Takacs et al., '97 (Norm.) Takacs et al., '01 Takacs et al., '07 Gagnon et al., '10 This work IAEA recommendation Talys-1.4 (TENDL-2011) 48 Ti(d,x) V 400 300 200 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Deuteron Energy (MeV) Fig. 5. Excitation function for the 60 500 Cross Section (mb) 6 0 nat Ti(d,x)44gSc nuclear reactions. Takacs et al., '97 (Norm.) Takacs et al., '07 This work 50 Cross Section (mb) In Cross Section (mb) 8 4. Results and discussion Hermanne et al., '00 Gagnon et al., '10 Talys-1.4 (TENDL-2011) 40 30 20 100 10 0 0 nat 0 10 20 Deuteron Energy (MeV) Fig. 2. Excitation function for the nat 30 Ti(d,x)48V nuclear reactions. 40 46 Ti(d,x) Sc 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Deuteron Energy (MeV) Fig. 6. Excitation function for the nat Ti(d,x)46Sc nuclear reactions. 18 M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 20 Takacs et al., '97 (Norm.) Hermanne et al., '00 Takacs et al., '07 Gagnon et al., '10 This work Talys-1.4 (TENDL-2011) Cross Section (mb) 16 12 8 nat 47 Ti(d,x) Sc 4 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Deuteron Energy (MeV) Fig. 7. Excitation function for the nat Ti(d,x)47Sc nuclear reactions. 14 Takacs et al., '97 (Norm.) Hermanne et al., '00 Takacs et al., '07 Gagnon et al., '10 This work Talys-1.4 (TENDL-2011) Cross Section (mb) 12 10 8 nat Ti(d,x)43Sc processes 6 4.2. 4 The relatively short-lived radionuclide 43Sc (T1/2 = 3.891 h) decays to the stable 43Ca with a b+ emission (88.1%) and an EC process (11.9%). Only one characteristic c-ray of 372.9 keV was used to identify this radionuclide. The measured cross-sections of 43Sc are shown in Fig. 3 together with only one earlier measurement by Takács et al. (1997) [8] and the theoretical data extracted from the TENDL-2011 library. As shown in Fig. 3, we confirmed the renormalized cross-sections of Takács et al. (1997) [8] for the first time. The populations of 43Sc are due to the direct nuclear reactions of 46Ti(d,na) (Q = 5.29 MeV) and 47Ti(d,2n + a) (Q = 14.18 MeV) as presented in Table 2. A relatively low cross-sections of 43Sc are due to the low abundances of the contributing target isotopes 46 Ti (8.25%) and 47Ti (7.44%) in the investigated energy region. The coulomb barrier effect in the exit channel may inhibit the contributions of the 46Ti(d,na) reaction immediately after its threshold energy (EThres = 5.5 MeV). The model code TALYS is unable to reproduce the measured excitation function for the natTi(d,x)43Sc reactions. 2 nat 48 Ti(d,x) Sc 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Deuteron Energy (MeV) Fig. 8. Excitation function for the 4.1. [23]. The natTi(d,x)48V cross-sections were measured by Takács et al. (1997) [8] based on the 27Al(d,x)24Na (Ed = 21 MeV; r = 54 mb) monitor reaction in the energy region of 2.95– 21.26 MeV. Therefore, we corrected the cross-sections using the updated monitor cross-sections recommended by IAEA (Ed = 21 MeV; r = 50.8 mb), and the corrected values agree well with our measured ones. The reported data by Jung [22] at 9.8–13.3 MeV show a disagreement in both shape and magnitudes. A downward energy shift of about 1 MeV could make an agreement of the crosssections by Jung [22] with our measurements. An excellent agreement is obtained with the IAEA recommended excitation function for the whole investigated energy region, and this fact confirms the reliability and accuracy of our measured cross-sections for the nat Ti(d,x)43,44m,44g,46,47,48Sc reactions. The model code TALYS produces a similar shape of the excitation function with an overestimation. Three direct reactions 47Ti(d,n) (Q = +4.6 MeV), 48Ti(d,2n) (Q = 7.02 MeV), and 49Ti(d,3n) (Q = 15.16 MeV) contribute to the formation of 48V in the present energy region. The TALYS code reveals that the maximum cross-sections around 17 MeV are due to the contribution of the 48Ti(d,2n) reaction on the abundant 48 Ti nuclide. nat Ti(d,x)48Sc nuclear reactions. nat Ti(d,x)48V processes The long-lived radionuclide 48V (T1/2 = 15.9735 d) completely decays to the stable nuclide 48Ti followed by an EC process (50.1%) and a b+ emission (49.9%). On the other hand, the relatively short-lived radionuclide 48Sc (T1/2 = 43.67 h) also decays to 48Ti via a b emission (100%). The intense c-rays of 983.525 keV and 1312.106 keV from excited states of 48Ti are the common c lines for 48V and 48Sc. An unambiguous identification of 48V could be done in two ways: using a less intense but an independent c line of 944.13 keV (7.87%) for 48V or using the spectra obtained after a sufficient cooling time of more than 450 h. In this work, we attempted both the ways, and found a very good agreement between them. The measured excitation function of 48V is shown in Fig. 2 together with the data available in the literature, and the theoretical data extracted from the TENDL-2011 library. Numerous authors investigated the natTi(d,x)48V reactions due to its importance in the beam monitoring applications. West et al. [23] reported isotopic cross-sections for the 47Ti(d,n)48V and 48 Ti(d,2n)48V reactions in the energy regions of 1.85–7.1 MeV and 7.13–34.56 MeV, respectively. The reported excitation functions were summed to obtain elemental cross-sections taking into account the isotopic abundances of natural titanium (47Ti: 7.28% and 48Ti: 73.72%). Although the (d,3n) and (d,4n) processes on 49 Ti (5.41%) and 50Ti (5.18%), respectively, may contribute to the production of 48V at higher deuteron energies, West et al. [23] neglected the contribution of these two processes in their reported data. Note that to keep the consistency in the renormalized excitation function, three scattered cross-sections of 48Ti(d,2n)48V (EThres = 7.3 MeV) around it’s threshold energy region (7.13– 8.24 MeV) were excluded from the renormalization process. An overall good agreement is found with the reported data by Gagnon et al. [25], Takács et al. (2007) [10], Takács et al. (2001) [9] except one point at 11.4 MeV, and by the renormalized data of West et al. 4.3. nat Ti(d,x)44mSc processes The relatively long-lived, high spin, and meta-stable radionuclide 44mSc (T1/2 = 58.61 h; 6+) directly decays to the 3285.0-keV energy level of the same spin state of 44Ca following an EC process (1.2%). Meanwhile, this isomeric state (44mSc) decays to its shortlived, and unstable low-spin state 44gSc (T1/2 = 3.97 h; 2+) via an IT (98.8%) process by emitting an intense c-ray of 271.241 keV. 44g Sc further decays to the 1157.02-keV level of the same spin state of 44Ca followed by an EC process and a b+ emission with a branching ratio of 98.95%. The remaining 44gSc nuclei decays to the 2656.48-keV (0.112%) and 3301.35-keV (0.014%) energy levels of the same spin state of 44Ca via an EC process. In this work, the strong and independent characteristic c line of 271.241 keV was used to obtain cross-sections of 44mSc, and the excitation function of the natTi(d,x)44mSc reaction is shown in Fig. 4 together with the literature data and the theoretical data extracted from the TENDL2011 library. We found a good agreement of our data with the recently measured ones by Gagnon et al. [25] and Takács et al. (2007) [10] at the low energy region. The data reported by Hermanne et al. [24] and the renormalized ones of Takács et al. (1997) [8] also show an agreement to our data within the error limits. The TALYS code produces a better fitted excitation function to the 19 M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 Table 3 Production cross-sections of the investigated radionuclides for the Deuteron energy (MeV) 2.7 ± 0.8 4.80 ± 0.62 6.66 ± 0.55 8.22 ± 0.51 9.59 ± 0.49 10.84 ± 0.47 12.00 ± 0.45 14.93 ± 0.42 17.49 ± 0.40 19.79 ± 0.38 21.91 ± 0.37 23.44 ± 0.36 nat Ti(d,x) nuclear processes. Measured cross-sections (mb) ðr Drstatistical Drothers Þ 48 43 V 1.03 ± 0.01 ± 0.07 16.44 ± 0.05 ± 1.08 18.56 ± 0.05 ± 1.22 24.68 ± 0.06 ± 1.62 90.42 ± 0.24 ± 5.93 166.1 ± 0.3 ± 10.9 222.8 ± 0.4 ± 14.6 303.6 ± 0.7 ± 19.9 325.5 ± 0.7 ± 21.3 304.3 ± 0.7 ± 20.0 255.9 ± 0.4 ± 16.8 224.7 ± 0.4 ± 14.7 44m Sc – – – – – – 0.10 ± 0.09 ± 0.01 1.15 ± 0.11 ± 0.08 2.96 ± 0.20 ± 0.19 4.03 ± 0.15 ± 0.26 4.82 ± 0.18 ± 0.32 4.77 ± 0.20 ± 0.31 44g Sc – 0.067 ± 0.006 ± 0.005 0.31 ± 0.01 ± 0.02 0.62 ± 0.01 ± 0.04 0.92 ± 0.02 ± 0.06 1.24 ± 0.03 ± 0.08 1.53 ± 0.14 ± 0.10 2.43 ± 0.16 ± 0.16 2.81 ± 0.15 ± 0.18 3.13 ± 0.23 ± 0.24 3.58 ± 0.24 ± 0.28 3.75 ± 0.15 ± 0.29 0.029 ± 0.001 ± 0.002 1.23 ± 0.01 ± 0.08 2.94 ± 0.02 ± 0.19 4.25 ± 0.04 ± 0.28 5.05 ± 0.05 ± 0.33 5.14 ± 0.09 ± 0.34 5.03 ± 0.09 ± 0.33 5.15 ± 0.09 ± 0.34 6.13 ± 0.10 ± 0.40 6.61 ± 0.11 ± 0.43 6.80 ± 0.11 ± 0.45 6.60 ± 0.11 ± 0.43 5 48 V 48 V ke V 44 g Sc 48 Sc g Sc 46 48 V 1 51 44 46 g Sc 4 Counts (#) 48 Sc m 43 Sc Sc 47 Sc 10 10 3 10 Energy: 17.49 MeV Counting time: 1200 s Cooling time: ~5 days Irradiation time: 7200 s 2 10 1 10 0 300 600 900 Photon Energy (keV) 1200 1500 Fig. 9. A typical c-ray spectrum from the activities induced in the natural titanium with an exposure of 17 MeV deuteron. 5 10 Energy < 2 MeV Counting time: 1200 s Cooling time: ~5 days Irradiation time: 7200 s 4 0.11 ± 0.01 ± 0.01 3.79 ± 0.05 ± 0.25 12.67 ± 0.08 ± 0.83 21.04 ± 0.10 ± 1.38 29.39 ± 0.31 ± 1.93 35.99 ± 0.42 ± 2.36 39.47 ± 0.33 ± 2.59 33.04 ± 0.62 ± 2.17 27.04 ± 0.51 ± 1.77 24.74 ± 0.50 ± 1.62 23.87 ± 0.35 ± 1.57 23.70 ± 0.37 ± 1.55 47 48 0.067 ± 0.002 ± 0.004 0.34 ± 0.01 ± 0.02 0.87 ± 0.01 ± 0.06 1.43 ± 0.01 ± 0.09 1.97 ± 0.02 ± 0.13 2.43 ± 0.06 ± 0.16 2.90 ± 0.09 ± 0.19 4.29 ± 0.16 ± 0.28 6.13 ± 0.20 ± 0.42 7.65 ± 0.18 ± 0.50 9.30 ± 0.20 ± 0.61 11.65 ± 0.22 ± 0.77 0.046 ± 0.002 ± 0.004 0.15 ± 0.01 ± 0.01 0.38 ± 0.01 ± 0.03 0.76 ± 0.02 ± 0.06 0.99 ± 0.04 ± 0.08 1.15 ± 0.05 ± 0.09 1.35 ± 0.16 ± 0.10 2.08 ± 0.15 ± 0.16 3.26 ± 0.15 ± 0.25 4.99 ± 0.21 ± 0.39 6.99 ± 0.21 ± 0.54 7.69 ± 0.18 ± 0.60 Sc Sc of 46Ti(d,a) (Q = +4.40 MeV), 47Ti(d,na) (Q = 4.48 MeV), and 48 Ti(d,2na) (Q = 16.10 MeV), and via an IT (98.80%) transition from the relatively long-lived isomer 44mSc (T1/2 = 58.61 h). Therefore, the 1157.020-keV photopeak area of 44gSc includes a contribution of 44gSc formed as a decay daughter of 44mSc. However, it is possible to evaluate an interference free area for 44gSc in the 1157.020-keV photopeak by using the spectra having a cooling time of around 40 h or more, i.e., more than 10 half-lives of 44g Sc; the detected area is due to the 44mSc via an IT process (98.80%). By using a typical decay curve analysis, the contribution of 44mSc in the 1157.020-keV was subtracted, and the independent cross-sections were determined for 44gSc. The measured excitation function for 44gSc is shown in Fig. 5. We found a good agreement of our data with the recently measured ones by Gagnon et al. [25]. An overall agreement within the error limit is also obtained with the renormalized data of Takács et al. (1997) [8] in the whole investigated energy region. The TALYS code reproduces a similar shape of the excitation function to the measured ones but overestimates it in absolute values. An analysis of the excitation function reveals that the gradual increasing trend of the cross-sections from 3 MeV to 12 MeV are due to the contribution of 46Ti(d,a) (Q = +4.40 MeV) and 47Ti(d,na) (Q = 4.48 MeV), whereas the flat maximum around 22 MeV is mostly due to the 48Ti(d,2n + a) (Q = 16.10 MeV) reaction. 4.5. 46 1 10 0 300 600 900 Photon Energy (keV) nat 46 48 V 1 51 47 Sc g Sc 48 V 2 10 1200 1500 Fig. 10. A typical c-ray spectrum from the activities induced in the natural titanium with an exposure of <2 MeV deuteron. experiments in the whole investigated energy region. Absence of any clear maximum indicates that a complex system of reactions on different target isotopes 46,47,48Ti would be involved in the formation of 44mSc within the present investigated energy region (see Table 2). Additionally, the contribution of major isotopes in the formation of 44mSc were checked with the TENDL-2011 library, and found supportive evidence for the aforementioned statement. 4.4. Sc 3 10 ke V Counts (#) 10 46g+m Sc nat Ti(d,x)44gSc processes The relatively short-lived and ground state radionuclide 44gSc (T1/2 = 3.97 h) is formed via two processes: via the direct reactions Ti(d,x)46Sc processes Sc has two states, a long-lived but unstable ground state 46gSc (T1/2 = 83.79 d) and a very short-lived isomeric state 46mSc (T1/2 = 18.75 s). 46mSc completely decays to its ground state by an IT process (100%) at the time of our measurements: the measured cross-sections of 46Sc are defined as the cumulative ones. The excellent agreement between the cross-sections determined from two intense c lines of 889.277 keV and 1120.545 keV confirmed the accuracy of our measurements. The measured excitation function of 46Sc is shown in Fig. 6. The literature data reported by Gagnon et al. [25] and Takács et al. (2007) [10] at the low energy region agree well with the present measurements. A downward energy shift of the excitation function by Hermanne et al. [24] could make an agreement with the present results. The renormalized data of Takács et al. (1997) [8] show a slightly larger cross-sections throughout the whole investigated energy region. The TALYS code reproduces a shape of the measured excitation function but underestimates it in magnitudes. As listed in Table 2, all of the target isotopes of natural Ti contribute to the formation of 46Sc via complex particle emissions in the energy region of interest. However, an analysis of the excitation function reveals that the sharp maximum around 12 MeV reflects the contribution of an abundant target isotope 48Ti via the 48Ti(d,a) (Q = +3.97 MeV) reaction. This is because M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 the other possible contributing reaction 46Ti(d,2p) (Q = 3.8 MeV) may find coulomb barrier effect in the exit channel, hence cannot contribute immediately after its threshold energy. Additionally, the possible contribution from the 46Ti(d,2p) (Q = 3.8 MeV) as well as 47Ti(d,n2p) (Q = 12.7 MeV) reactions were cross checked using the data from the TENDL-2011 library which confirmed the aforementioned statement. 4.6. nat Ti(d,x)47Sc processes 10 48 0.1 44m This work ( Sc) 44m Dmitriev et al. ( Sc) 0.01 46 This work ( Sc) 46 Dmitriev et al. ( Sc) 47 Sc (T1/2 = 3.3492 d) decays to the stable nuclide 47Ti via a b emission (100%). The intense and independent c line of 159.38 keV was used to identify this radionuclide. The measured excitation function of 47Sc is shown in Fig. 7. The data measured by Gagnon et al. [25] and Takács et al. (2007) [10] at the low energy region show a very good agreement with the present results. An overall good agreement is also obtained between the corrected data of Takács et al. (1997) [8] and the present results in the whole investigated energy region. The cross-sections reported by Hermanne et al. [24] show an agreement to the present results by slightly shifting the excitation function downwards, though a good agreement is seen above 20 MeV. The TALYS code reproduces a shape of the experimental excitation function but overestimates it above 15 MeV. 1E-3 4.7. This work ( Sc) 47 This work ( Sc) 47 Dmitriev et al. ( Sc) 1 Yield (MBq/µ A-h) 20 Ti(d,x)48Sc processes 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Deuteron Energy (MeV) Fig. 11. Physical thick target yields for the 48,47,46,44m Sc radionuclides. 45 44g This work ( Sc) 43 This work ( Sc) 48 This work ( V) 48 Dmitriev et al. ( V) 48 Valikova et al. ( V) Yield (MBq/µA-h) 40 30 20 10 nat 48 0 -2 48 Sc (T1/2 = 43.67 h) decays to the stable nuclide Ti by releasing a b particle (100%). 48Sc is formed only by the direct nuclear reactions listed in Table 2. The most intense c lines 983.526 keV and 1312.120 keV were not used to identify 48Sc due to the interferences of 48V as mentioned above. Thus, the independent c line of 1037.522 keV (Ic = 97.6%) was used to assess the radioactivity of 48 Sc. The assessed radioactivity of 48Sc was also confirmed with another c line of 175.361 keV (Ic = 7.48%). The excitation function of 48 Sc is shown in Fig. 8. No clear peak is seen in the measured excitation function in the investigated energy region. We found a good agreement between our data and the earlier ones by Gagnon et al. [25], Takács et al. (2007) [10], Hermanne et al. [24], and the renormalized ones of Takács et al. (1997) [8]. The TALYS code cannot reproduce the distorted excitation function as shown in Fig. 8. 4.8. Contributions from secondary neutrons Secondary neutrons from elastic break-up of deuterons may also contribute to the production of the investigated scandium radionuclides via (n,x) reactions, though it is difficult to evaluate this effect in the complex c-ray spectra. However, this effect was evaluated to be negligible for all radionuclides of interest in this work by irradiating two extra foils at the back side of the stack where the induced deuteron energy was ranged out (below 2 MeV). To understand this situation more clearly, two experimental c-ray spectra having exposed energy of 17 MeV and <2 MeV are presented in the Figs. 9 and 10, respectively. Additionally, by considering the present experimental conditions such as the total thickness of the irradiated stack (1.09 mm), covered deuteron energy range (low energy irradiation environment 2–24 MeV), observing a very much negligible area only for few long-lived radionuclides for the foil with an exposed energy of <2 MeV (See counts in Fig. 10 relative to the corresponding nuclei in Fig. 9) etc., the estimated effect of the neutrons were neglected. Similarly, the contribution of secondary protons was also considered to be negligible. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Deuteron Energy (MeV) Fig. 12. Physical thick target yields for the 48 V and 44g,43 Sc radionuclides. 5. Thick target yields Physical thick target yields (physical yields [34]) were deduced for all of the investigated radionuclides 48V, 43Sc, 44mSc, 44gSc, 46Sc, 47 Sc, and 48Sc using the measured cross-sections and the electronic stopping power of natTi over the energy range from a respective threshold to the initial deuteron energy by taking into account that the total energy is absorbed in the target. A detailed explanation about the deduction of the yield is available elsewhere [28]. The deduced yield is expressed as MBq/lA-h, i.e. the radioactivity corresponding to the yield of radionuclides produced by beam particles with electric charge of 1 lA 1 h (=3.6 mC). The deduced yields are shown in Figs. 11 and 12 as a function of the deuteron energy with the directly measured thick target yield in the literature. Dmitriev et al. [57] reported the thick target yields for the production of 48V, 44mSc, 46Sc and 47Sc by irradiating a thick natural titanium target with a 22-MeV deuteron beam. Their target was thick enough to cover the energy range from a threshold to 22 MeV. The present thick target yields show an excellent agreement with the directly measured ones for 46Sc and 48V by Dmitriev et al. [57]. However, 47Sc yield reported by Dmitriev et al. [57] was not confirmed by the present investigations. The physical thick target yields reported for 48V by Vakilova et al. [58] in the energy region of 4 to 12 MeV also agree well with the present ones as shown in Fig. 12. 6. Conclusions functions for the formation of 48V and Sc via the natTi(d,x) nuclear reactions were measured in the energy range of 2–24 MeV using a stacked-foil Excitation 43,44m,44g,46,47,48 M.U. Khandaker et al. / Nuclear Instruments and Methods in Physics Research B 296 (2013) 14–21 activation technique with an overall uncertainty of about 11%. Measured data were critically compared with the available literature data and found an overall good agreement, whereas partial agreements were obtained with the theoretical calculations based on the TALYS code. The physical thick target yields for the investigated radionuclides were also deduced using the measured crosssections, and found a good agreement with the directly measured thick target yields in the literature. The shape of the IAEA recommended monitor cross-sections for natTi(d,x)48V reaction was verified. Above all, the measured cross-sections of the 48V, 43Sc, 44mSc, 44g Sc, 46Sc, 47Sc, and 48Sc via deuteron irradiation on natural titanium targets could play an important role in enrichment of the literature database leading to various practical applications. In most cases, it has been reported that TENDL-2011 cannot reproduce the measured excitation functions properly, and we confirmed that the adopted nuclear reaction models and parameter set in TALYS-1.4 for the production of TENDL-2011 are not sufficient enough to describe the investigated reactions precisely. Acknowledgements This work was performed at the RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo. The authors would like to express their sincere thanks to the staffs of the AVF cyclotron for an excellent beam operation. The work was partially supported by the University of Malaya Research Grant (RG13911AFR). References [1] G.W. Severin, J.W. Engle, H.F. Valdovinos, T.E. Barnhart, R.J. Nickles, Appl. Radiat. Isot. 70 (2012) 1526. [2] C. Grignon, J. Barbet, M. Bardièe‘s, T. Carlier, J.F. Chatal, O. Couturier, J.P. Cussonneau, A. Faivre, L. Ferrer, S. Girault, T. Haruyama, P. Le Ray, L. Luquin, S. Lupone, V. Mé étivier, E. Morteau, N. Servagent, D. Thers, Nucl. Instrum. Methods Phys. Res. A 571 (2007) 142. [3] A. Majkowska-Pilip, A. Bilewicz, J. Inorg. Biochem. 105 (2) (2011) 313. [4] L.F. Masuner, K.L. Kolsky, V. Joshi, S.C. Srivastava, Appl. Radiat. Isot. 49 (4) (1998) 285. [5] R.W. Baer, B.D. Payne, E.D. Verrier, G.J. Vlahakes, D. Molodowitch, P.N. Uhlig, J.I. Hoffman, Am. J. Physiol. Heart Circ. Physiol. 246 (3) (1984) H418. [6] A.P. Wehner, C.L. Wilerson, D.L. Stevens, Environ. Res. 35 (1) (1984) 211. [7] M. Inoue, K. Komura, Chikyu Kagaku (in Japanese) 35 (1) (2001) 13. [8] S. Takács, M. Sonck, B. Scholten, A. Hermanne, F. Tárkányi, Appl. Radiat. Isot. 48 (1997) 657. [9] S. Takács, F. Szelecsenyi, F. Tárkányi, M. Sonck, A. Hermanne, Y. Shubin, A. Dityuk, M.G. Mustafa, Z. Youxiang, Nucl. Instrum. Methods Phys. Res. B 174 (2001) 235. [10] S. Takács, B. Király, F. Tárkányi, A. Hermanne, Nucl. Instrum. Methods Phys. Res. B 262 (2007) 7. [11] R.D. Hichwa, D. Kadrmas, G.L. Watkins, S.D. Wollenweber, S. Maniam, L.L. Boles Ponto, J.C.W. Richmond, J.A. Koeppel, Nucl. Instrum. Methods Phys. Res. B 99 (1995) 804. [12] K. De Cremer, R. Cornelis, K. Strijckmans, R. Dams, N. Lameire, R. Vanholder, J. Chromatogr. B Anal. Technol. Biomed. Life Sci. 775 (2002) 143 (abstract). [13] L.X. Tham, N. Nagasawa, S. Matsuhashi, N.S. Ishioka, T. Ito, T. Kume, Radiat. Phys. Chem. 61 (2001) 171. [14] J.M.L. Ouellet, K. Oxorn, L.A. Hamel, L. Lessard, C. Matte, Nucl. Instrum. Methods Phys. Res. B 79 (1993) 579. [15] N. Achtziger, W. Witthuhn, Mater. Sci. Eng. B 46 (1997) 333. [16] E. Rorat, B. Petelenz, B. Marczewska, E. Ochab, Radiat. Measurments 39 (2005) 495. [17] A. Arbabi, M. Sadeghi, M. Joharifard, Appl. Radiat. Isot. 67 (2009) 129. [18] K. De Cremer, R. Cornelis, K. Strijckmans, R. Dams, N. Lameire, R. Vanholder, J. Chromatogr. B 775 (2002) 143. [19] P.M. Racolta, L. Popa-Simil, N. Miron, C.I. Muntele, Nucl. Instrum. Methods Phys. Res. B 139 (1998) 461. [20] W.H. Burgus, G.A. Cowan, J.W. Hadley, W. Hess, T. Shull, M.L. Stevenson, H.F. York, Phys. Rev. 95 (1954) 750. [21] K.L. Chen, J.M. Miller, Phys. Rev. 134 (1964) B1269. [22] P. Jung, Cross sections for the production of helium and long-living radioactive isotopes by protons and deuterons, in: Conference on Nucl. Data Sci. Technol., Juelich, 1991, p. 352. 21 [23] H.I. West Jr., R.G. Lanier, M.G. Mustafa, in: Excitation Functions for the Nuclear Reactions on Titanium Leading to the Production of 48V48V, 44Sc, and 47Sc by Proton, Deuteron and Triton Irradiations at 0–35 MeV, U.C., Lawrence Rad. Lab., Berkeley and Livermore, 1993, p. 1 (UCRL-ID-115738). [24] A. Hermanne, M. Sonck, S. Takács, F. Tárkányi, Nucl. Instrum. Methods Phys. Res. B 161–163 (2000) 178. [25] K. Gagnon, M.A. Avila-Rodriguez, J. Wilson, S.A. McQuarrie, Nucl. Instrum. Methods Phys. Res. B 268 (2010) 1392. [26] F. Tárkányi, F. Ditrói, S. Takács, A. Hermanne, M. Baba, A.V. Ignatyuk, Nucl. Instrum. Methods Phys. Res. B 269 (2011) 1792. [27] M.U. Khandaker, M.S. Uddin, K.S. Kim, Y.S. Lee, G.N. Kim, Nucl. Instrum. Methods Phys. Res. B 262 (2007) 171. [28] M.U. Khandaker, K.S. Kim, G.N. Kim, N. Otuka, Nucl. Instrum. Methods Phys. Res. B 268 (2010) 2303. [29] M.U. Khandaker, K.S. Kim, M.W. Lee, K.-S. Kim, G.N. Kim, Nucl. Instrum. Methods Phys. Res. B 269 (2011) 1140. [30] M.U. Khandaker, K. Kim, M.W. Lee, K.S. Kim, G.N. Kim, Y.S. Cho, Y.O. Lee, Nucl. Instrum. Methods Phys. Res. B 266 (2008) 4877. [31] M.U. Khandaker, K.S. Kim, K.-S. Kim, M.W. Lee, G.N. Kim, Nucl. Instrum. Methods Phys. Res. B 266 (2008) 5101. [32] M.U. Khandaker, K.S. Kim, K.-S. Kim, M.W. Lee, Y.S. Lee, G.N. Kim, Y.-S. Cho, Y.O. Lee, Nucl. Instrum. Methods Phys. Res. B 267 (2009) 23. [33] M. Berglund, M.E. Wieser, Pure Appl. Chem. 83 (2011) 397. [34] S.M. Qaim, F. Tárkányi, P. Obložinský, K. Gul, A. Hermanne, M.G. Mustafa, F.M. Nortier, B. Scholten, Y. Shubin, S. Takács, Y. Zhuang, in: Charged Particle CrossSection Database for Medical Radioisotope Production: Diagnostic Radioisotopes and Monitor Reactions, IAEA-TECDOC-1211, Vienna, 2001. Data updated in January 2007. Available from: <http://www.nds.iaea.org/ medical/>. [35] J.F. Ziegler, Nucl. Instrum. Methods Phys. Res. B 219–220 (2004) 1027; J.F. Ziegler, J.P. Biersack, U. Littmark, SRIM 2003 code, Version 96.xx, The Stopping and Range of Ions in Solids, Pergamon, New York. Available from: <http://www.srim.org/>. [36] J.A. Cameron, B. Singh, Nucl. Data Sheets 92 (2001) 783 (A = 43). [37] J. Chen, B. Singh, J.A. Cameron, Nucl. Data Sheets 112 (2011) 2357 (A = 44). [38] S.-C. Wu, Nucl. Data Sheets 91 (2000) 1 (A = 46). [39] T.W. Burrows, Nucl. Data Sheets 108 (2007) 923 (A = 47). [40] T.W. Burrows, Nucl. Data Sheets 107 (2006) 1747 (A = 48). [41] NuDat 2.6 software, National Nuclear Data Center, Brookhaven National Laboratory. Available from: <http://www.nndc.bnl.gov/nudat2/>. [42] G. Audi, A.H. Wapstra, Nucl. Phys. A 595 (1995) 409 (Data updated in 2011 by G. Audi, W. Meng). [43] Qtool: Calculation of Reaction Q-values and Thresholds, Los Alamos National Laboratory, T-2 Nuclear Information Service. Available from: <http:// t2.lanl.gov/data/qtool.html>. [44] A.I. Dityuk, A.Yu. Konobeyev, V.P. Lunes, Yu.N. Shubin, Report INDC(CCP)-410, International Atomic Energy Agency (1998). [45] A.J. Koning, D. Rochman, Nucl. Data Sheets 113 (2012) 2841; A.J. Koning, S. Hilaire, M.C. Duijvestijn, TALYS-1.0, in: O. Bersillon, F. Gunsing, E. Bauge, R. Jacqmin, S. Leray (Eds.), Proceedings of the International Conference on Nuclear Data for Science and Technology, Nice, France, 22–27 April, 2007, p. 211. [46] M. Herman, R. Capote, B.V. Carlson, P. Obložinský, M. Sin, A. Trkov, H. Wienke, V. Zerkin, Nucl. Data Sheets 108 (2007) 2655. [47] M. Avrigeanu, V. Avrigeanu, J. Phys. Conf. Ser. 205 (2010) 012014. [48] M. Avrigeanu, V. Avrigeanu, J. Korean Phys. Soc. 59 (2) (2011) 903. [49] P. Bém, E. Šimečková, M. Honusek, U. Fischer, S.P. Simakov, R.A. Forrest, M. Avrigeanu, A.C. Obreja, F.L. Roman, V. Avrigeanu., Phys. Rev. C 79 (2009) 044610. [50] E. Šimečková, P. Bém, M. Honusek, M. Štefánik, U. Fischer, S.P. Simakov, R.A. Forrest, A.J. Koning, J.-C. Sublet, M. Avrigeanu, F.L. Roman, V. Avrigeanu., Phys. Rev. C 84 (2011) 014605. [51] F. Tárkányi, A. Hermanne, S. Takács, K. Hilgers, S.F. Kovalev, A.V. Ignatyuk, S.M. Qaim, Appl. Radiat. Isot. 65 (2007) 1215. [52] A.V. Ignatyuk, Report INDC(NDS)-0602, p12, International Atomic Energy Agency (2012). [53] C. Kalbach Walker, Triangle Universities Nuclear Laboratory, Report (2001). [54] P.G. Young, E.D. Arthur, M.B. Chadwick, Report LA-UR-96-3739, Los Alamos National Laboratory (1996). [55] A.J. Koning, D. Rochman, Talys based evaluated nuclear data library (TENDL) data library. Available from: <ftp://ftp.nrg.eu/pub/www/talys/tendl2011/>. [56] N. Otuka, S. Dunaeva, E. Dupont, O. Schwerer, A. Blokhin, J. Korean. Phys. Soc. 59 (2011) 1292. Available from: <http://www.nds.iaea.org/exfor/>. [57] P.P. Dmitriev, N.N. Krasnov, G.A. Molin, Radioactive nuclide yields for thick target at 22 MeV deuterons energy, Vop. At. Nauki i Tekhn., Ser. Yadernye Konstanty 4 (1982) 38, Russia (English translation: R, INDC(CCP)-210/L,1983) Report: USSR report to the I.N.D.C., No.210/L (1983)). [58] G. Vakilova, A. Vasidov, S. Mukhammedov, E. Pardaev, A. Rakhmanov, Zh. Saidmuradov, The determination sensitivities of certain elements with z less or equal 42 using a deutron activation method in a cyclotron. Atomnaya Energiya 55 (1983) 164, Russia (English translation: Soviet Atomic Energy 55 (1983) 598, USA).
© Copyright 2026 Paperzz