Evaluation of nuclear reaction cross sections for optimization of production of the important non-standard positron emitting radionuclide 89Zr using proton and deuteron induced reactions on 89Y target.

89Zr (T1/2 = 3.27 d) is an important ß+-emitting radionuclide of zirconium used in immuno PET. The excitation functions of the 89Y(d,2n)89Zr and 89Y(p,n)89Zr reactions were analyzed to deduce the optimum conditions for the high purity production of 89Zr. The nuclear model codes ALICE-IPPE, EMPIRE 3.2 and TALYS 1.9 were used to check the consistency and reliability of the experimental data. A polynomial fit to the chosen data for each reaction gave the excitation function, which was then used for the integral yield calculation of the product. The amount of the major radioactive impurity 88Zr was precisely analyzed for both the proton and the deuteron induced reactions on the 89Y target.

Nuclear model analysis of excitation functions of α-particle induced reactions on In and Cd up to 60MeV with relevance to the production of high specific activity 117mSn.

Excitation functions were calculated for the α-particle induced reactions 115In(α,x)117mSn, 114Cd(α,n)117mSn, 116Cd(α,3n)117mSn and natCd(α,x)117mSn to analyse the production of the medically important 117mSn (T½ = 13.6 d). For calculations three nuclear model codes (i.e. TALYS, EMPIRE and ALICE-IPPE) were used and the results were compared with the available experimental data. For the most important reaction, 116Cd(α,3n)117mSn, evaluated data are presented. The yield and radionuclidic purity of 117mSn from each reaction are discussed.

Evaluation of nuclear reaction cross section data for the production of (87)Y and (88)Y via proton, deuteron and alpha-particle induced transmutations.

Proton, deuteron and alpha-particle induced reactions on (87,88)Sr, (nat)Zr and (85)Rb targets were evaluated for the production of (87,88)Y. The literature data were compared with nuclear model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The evaluated cross sections were generated; therefrom thick target yields of (87,88)Y were calculated. Analysis of radio-yttrium impurities and yield showed that the (87)Sr(p, n)(87)Y and (88)Sr(p, n)(88)Y reactions are the best routes for the production of (87)Y and (88)Y respectively. The calculated yield for the (87)Sr(p, n)(87)Y reaction is 104 MBq/µAh in the energy range of 14→2.7MeV. Similarly, the calculated yield for the (88)Sr(p, n)(88)Y reaction is 3.2 MBq/µAh in the energy range of 15→7MeV.

Evaluation of nuclear reaction cross sections for optimization of production of the emerging diagnostic radionuclide 55Co.

The excitation functions of the (54)Fe(d,n)(55)Co, (56)Fe(p,2n)(55)Co and (58)Ni(p,α)(55)Co reactions were analyzed with relevance to the production of the ß(+)-emitter (55)Co (T½=17.53 h), a promising cobalt radionuclide for PET imaging. The nuclear model codes ALICE-IPPE, EMPIRE and TALYS were used to check the consistency of the experimental data. The statistically fitted excitation function was employed to calculate the integral yield of the product. The amounts of the radioactive impurities (56)Co and (57)Co were assessed. A comparison of the three investigated production routes is given.

Target development for diversified irradiations at a medical cyclotron.

The irradiation facility at an old medical cyclotron (Ep=17 MeV; Ed=10 MeV) was upgraded by extending the beam line and incorporation of solid state targetry. Tests performed to check the quality of the available beam are outlined. Results on nuclear data measurements and improvement of radiochemical separations are described. Using solid targets, with the proton beam falling at a slanting angle of 20°, a few radionuclides, e.g. (75)Se, (120)I, (124)I, etc. were produced with medium currents (up to 20 µA) in no-carrier-added form in quantities sufficient for local use. The extended irradiation facility has considerably enhanced the utility of the medical cyclotron.

Nuclear model analysis of excitation functions of proton induced reactions on 86Sr, 88Sr and natZr: Evaluation of production routes of 86Y.

The proton induced nuclear reactions on (86)Sr, (88)Sr and (nat)Zr were investigated for the production of (86)Y. The literature data were compared with the results of nuclear model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The thick target yields of (86)Y were calculated from the recommended excitation functions. Analysis of radioyttrium impurities was also performed. A comparison of the various production routes showed that for medical applications of (86)Y, the reaction (86)Sr(p,n)(86)Y is the method of choice, which gives efficient yield with minimum impurities.

Evaluation of excitation functions of the (68,67,66)Zn(p,xn)(68,67,66)Ga and 67Zn(p,α)64Cu reactions: validation of evaluated data through comparison with experimental excitation functions of the (nat)Zn(p,x)(66,67)Ga and (nat)Zn(p,x)64Cu processes.

Experimentally available cross section data for formation of the radionuclides (68)Ga, (67)Ga, (66)Ga and (64)Cu in proton induced reactions on enriched (68)Zn, (67)Zn and (66)Zn were evaluated by comparison with the excitation functions calculated by the nuclear model codes, EMPIRE and TALYS, followed by statistical fitting of the selected data. The recommended cross sections were used to obtain the integral yields. The validation of the recommended excitation functions was also attempted by normalization to (nat)Zn and comparison with the experimental data for the (nat)Zn(p,x)(67)Ga, (nat)Zn(p,x)(66)Ga and (nat)Zn(p,x)(64)Cu processes.

Nuclear model analysis of excitation functions of proton and deuteron induced reactions on (64)Zn and (3)He- and α-particle induced reactions on (59)Co leading to the formation of copper-61: Comparison of major production routes.

Cross section data for formation of the medically important radionuclide (61)Cu (T½=3.33h) in proton and deuteron induced reactions on enriched (64)Zn and in (3)He- and α-particle induced reactions on (59)Co were analyzed by using the nuclear model calculational codes, EMPIRE and TALYS. A well-defined statistical procedure was then employed to derive the recommended excitation functions, and therefrom to obtain integral yields. A comparison of major production routes of (61)Cu was done.

Nuclear model analysis of excitation functions of proton, deuteron and α-particle induced reactions on nickel isotopes for production of the medically interesting copper-61.

Excitation functions of the (61)Ni(p,n)(61)Cu, (62)Ni(p,2n)(61)Cu, (60)Ni(d,n)(61)Cu and (58)Ni(α,p)(61)Cu reactions were analyzed with respect to the production of (61)Cu (T½=3.33 h), a promising radionuclide for PET imaging. The nuclear model codes EMPIRE and TALYS reproduced the experimental data of all reactions well, except those for the (d,n) process. The fitted excitation functions were employed to calculate the integral yield of (61)Cu in all reactions. The amounts of the possible impurities (62)Cu and (60)Cu were assessed. A validation of the evaluated (p,xn) data was attempted.

Evaluation of excitation functions of 100Mo(p,d+pn)99Mo and 100Mo (p,2n)99mTc reactions: Estimation of long-lived Tc-impurity and its implication on the specific activity of cyclotron-produced (99m)Tc.

Excitation functions were calculated by the code TALYS for 10 proton-induced reactions on (100)Mo. For (100)Mo(p,d+pn)(99)Mo and (100)Mo(p,2n)(99m)Tc, calculations were also performed using the code STAPRE. Furthermore, for those two reactions and (nat)Mo(p,x)(96)Tc, evaluation of available experimental data was also carried out. The production of (99m)Tc via the (100)Mo(p,2n)-process is discussed. The ratio of atoms of long-lived (99g)Tc and (98)Tc to those of (99m)Tc is appreciably higher in cyclotron production than in generator production of (99m)Tc; this may adversely affect the preparation of (99m)Tc-chelates.

Evaluation of excitation functions of proton, ³He- and α-particle induced reactions for production of the medically interesting positron-emitter bromine-76.

Cross section data for production of the medically interesting radionuclide 76Br (T(½)=16.2 h) via the proton induced reactions on 76Se, 77Se, 78Se and 79Br, and ³He- and α-particle induced reactions on 75As were evaluated. The nuclear model codes STAPRE, EMPIRE and TALYS were used to check the consistency in the experimental data and a statistical procedure was applied to derive the recommended excitation functions. A comparison of various production routes of 76Br (and of 75Br) is presented.

Excitation functions of α-particle induced reactions on enriched 123Sb and (nat)Sb for production of 124I.

Excitation functions of (α,xn) reactions on 98.28% enriched (123)Sb and on (nat)Sb were measured from 9 to 40 MeV. The data could be described well in terms of statistical and precompound models using the code TALYS. The discrepancies in the literature data for the formation of (125)I and (126)I were solved. The nuclear reaction (123)Sb(α,3n)(124)I on an enriched target appears to be interesting for the production of (124)I (T(1/2)=4.18 d) over the energy range E(α)=42→32 MeV, its yield being 11.7 MBq/µAh. The levels of the radionuclidic impurities (125)I and (126)I amount to 1.8% and 0.6%, respectively. The use of (nat)Sb as target material for (124)I production is unsuitable due to the high level of (123)I impurity.

Evaluation of excitation functions of 3He- and α-particle induced reactions on antimony isotopes with special relevance to the production of iodine-124.

Cross section data were evaluated for the production of the medically important positron emitter (124)I (T(1/2)=4.18d) via (3)He- and α-particle induced reactions on Sb isotopes. The consistency in the measured data available in the literature was checked against the cross section calculations of three nuclear model codes (i.e. STAPRE, EMPIRE and TALYS). The recommended excitation functions obtained by a statistical procedure were used to derive the integral yields. An assessment of the (124)I yields and associated radioisotopic impurities suggests that the (123)Sb(α,3n)(124)I process over the energy range of E(α)=45 → 32 MeV could be of potential interest for the production of (124)I.

Experimental studies and nuclear model calculations on proton induced reactions on manganese up to 45 MeV with reference to production of (55)Fe, (54)Mn and (51)Cr.

Excitation functions of the reactions (55)Mn(p,n)(55)Fe, (55)Mn(p,x)(54)Mn and (55)Mn(p,x)(51)Cr were measured from their respective thresholds up to 18 MeV in the first case and up to 45 MeV in the latter two cases, using the conventional stacked-foil technique. The radioactivity of (55)Fe was determined via high resolution X-ray spectrometry and of other radionuclides via high resolution γ-ray spectrometry. Nuclear model calculations were performed using the codes ALICE-IPPE, EMPIRE and TALYS. In some cases, good agreement was found between the experimental and theoretical data while in others considerable deviations were observed. From the experimental data the expected integral yields of the three investigated radionuclides were calculated.

Radiochemical determination of cross sections of alpha-particle induced reactions on 192Os for the production of the therapeutic radionuclide 193mPt.

For determination of cross sections of alpha-particle induced reactions on 99.65% enriched (192)Os, the methods for electrolytic preparation of thin samples and radiochemical separation of radioplatinum were optimized. The excitation functions of the (192)Os(alpha,n)(195m)Pt and (192)Os(alpha,3n) (193m)Pt reactions were measured from 20 to 39 MeV. The cross section of the latter reaction reaches a maximum value of about 1.5b at an energy around 36 MeV. The results of nuclear model calculations using the codes TALYS and STAPRE agreed well with the measured data. The optimum energy range for the production of no-carrier-added (193m)Pt (T(1/2)=4.33 d) was found to be E(alpha)=40-->30 MeV. The thick target yield amounts to 10 MBq/microA h and a possible batch yield of 2 GBq should be sufficient for Auger electron therapy on a wide scale.

Evaluation of excitation functions of proton and deuteron induced reactions on enriched tellurium isotopes with special relevance to the production of iodine-124.

Cross-section data for the production of medically important radionuclide (124)I via five proton and deuteron induced reactions on enriched tellurium isotopes were evaluated. The nuclear model codes, STAPRE, EMPIRE and TALYS, were used for consistency checks of the experimental data. Recommended excitation functions were derived using a well-defined statistical procedure. Therefrom integral yields were calculated. The various production routes of (124)I were compared. Presently the (124)Te(p,n)(124)I reaction is the method of choice; however, the (125)Te(p,2n)(124)I reaction also appears to have great potential.

An Am/Be neutron source and its use in integral tests of differential neutron reaction cross-section data.

An Am/Be neutron source, installed recently at the Rajshahi University, is described. Neutron flux mapping was done using the nuclear reactions (197)Au(n,gamma)(198)Au, (113)In(n,gamma)(114m)In, (115)In(n,n'gamma)(115m)In and (58)Ni(n,p)(58)Co. An approximate validation of the neutron spectral shape was done using five neutron threshold detectors and the iterative unfolding code SULSA. Integral cross sections of the reactions (54)Fe(n,p)(54)Mn, (59)Co(n,p)(59)Fe and (92)Mo(n,p)(92m)Nb were measured with fast neutrons (E(n)>1.5MeV) and compared with data calculated using the neutron spectral distribution and the excitation function of each reaction given in data libraries: an agreement within +/-6% was found.

A comprehensive evaluation of charged-particle data for production of the therapeutic radionuclide (103)Pd.

(103)Pd is an important radionuclide having a half-life of 16.99d, which is suitable for internal radiation therapy, especially used for the treatment of prostate cancer. Its production in no-carrier-added form is done via charged-particle-induced reactions and the data are available in EXFOR library. We evaluated six charged-particle-induced reactions, namely (nat)Ag(p,x)(103)Pd, (103)Rh(p,n)(103)Pd, (103)Rh(d,2n)(103)Pd, (100)Ru(alpha,n)(103)Pd, (101)Ru(alpha,2n)(103)Pd, and (102)Ru((3)He,2n)(103)Pd process. In the first case, analysis was done up to about 100MeV but in other cases only up to about 25 or 40MeV. Furthermore, an evaluation of the data for the (nat)Ag(p,x)(103)Ag process was also done since it may serve as a typical example for the (103)Ag-->(103)Pd precursor system. A statistical procedure supported by nuclear model calculations using the codes STAPRE, EMPIRE 2.19, and TALYS was used to validate and fit the experimental data. The recommended sets of data derived together with confidence limits are reported. The application of those data, particularly in the calculation of integral yields, is discussed. A comparison of the investigated routes from the viewpoint of practical applicability to the production of (103)Pd is given. Presently the (103)Rh(p,n)(103)Pd reaction is the method of choice.

Excitation function of the 192Os(3He,4n)-reaction for production of 191Pt.

In search of an alternative production route of the therapeutically and environmentally interesting radionuclide (191)Pt (T(1/2)=2.8 d), excitation function of the (192)Os((3)He,4n)(191)Pt reaction was measured from its threshold up to 36 MeV. Thin samples of enriched (192)Os were prepared by electrodeposition on Ni-foils, and the conventional stacked-foil technique was used for cross-section measurements. The experimental data were compared with the results of theoretical calculations using the codes ALICE-IPPE and TALYS. Good agreement was found with TALYS. The theoretical thick target yield of (191)Pt over the energy range E(3He)=36-->25 MeV amounts to 6.7 MBq/microA h. A comparison of various investigated production methods of (191)Pt is given. The here investigated (192)Os((3)He,4n)-process leads to very high-purity (191)Pt (>99.5%).

Excitation functions of proton-induced reactions on natFe and enriched 57Fe with particular reference to the production of 57Co.

Excitation functions of the reactions (nat)Fe(p,xn)(55,56,57,58)Co, (nat)Fe(p,x)(51)Cr, (nat)Fe(p,x)(54)Mn, (57)Fe(p,n)(57)Co and (57)Fe(p,alpha)(54)Mn were measured from their respective thresholds up to 18.5MeV, with particular emphasis on data for the production of the radionuclide (57)Co (T(1/2)=271.8d). The conventional stacked-foil technique was used, and the samples for irradiation were prepared by an electroplating or sedimentation process. The measured excitation curves were compared with the data available in the literature as well as with results of nuclear model calculations. From the experimental data, the theoretical yields of the investigated radionuclides were calculated as a function of the proton energy. Over the energy range E(p)=15-->5MeV the calculated yield of (57)Co from the (57)Fe(p,n)(57)Co process amounts to 1.2MBq/microAh and from the (nat)Fe(p,xn)(57)Co reaction to 0.025MBq/microAh. The radionuclidic impurity levels are discussed. Use of highly enriched (57)Fe as target material would lead to formation of high-purity (57)Co.