Excitation function of 122 Te(d, n) 123 I nuclear reaction: production of 123 I at a low energy cyclotron S. TakaÂcs a , A. Azzam a, *, M. Sonck b , F. SzelecseÂnyi a , Z. KovaÂcs a , A. Hermanne b , F. TaÂrkaÂnyi a, { a Institute of Nuclear Research of the Hungarian Academy of Sciences, POB 51, 4001, Debrecen, Hungary b Cyclotron Department, Vrije Universiteit Brussel (VUB), 1090, Brussels, Belgium Received for publication 24 March 1998 Abstract The excitation function of the 122 Te(d, n) 123 I nuclear reaction has been measured from threshold up to 21 MeV by the stacked foil irradiation technique. Good agreement was obtained with the results of the recent model calculations but an energy shift of 2 MeV to lower energy can be seen when comparing with cross section measured earlier. Integral yields have been deduced from the measured excitation function and have been compared with experimental thick target yields found in the literature. A comparison of the yields of the proton and deuteron induced reactions for production of 123 I is given. # 1999 Elsevier Science Ltd. All rights reserved. 1. Introduction The 123 I(T 1/2 = 13.2 h, E g = 159 keV) radioisotope has found wide application in diagnostic nuclear medi- cine. Several detailed reviews have been written on its production methods (cf. StoÈcklin, 1977; Qaim and StoÈcklin, 1983; Qaim, 1986) and the subject has been discussed at many conferences. Some cross section measurements relevant to its production at small and medium energy cyclotrons have, however, shown that some of the earlier results on main and side reactions need critical reinvestigation. There exist discrepancies among others on the cross section/yield data of 123 Te(p, n) 123 I, 122 Te(d, n) 123 I, 124 Te(d, xn) 123,124 I, 124 Xe(p, x) 123 I and nat Te(p, xn) 123 I reactions. The sta- tus of the data of proton and deuteron induced reac- tions will be published separately. The production of 123 I at low energy compact cyclo- trons (E p R15±17 MeV, E d R10 MeV) was critically discussed by Scholten et al. (1989). The 123 Te(p, n) 123 I reaction is the most preferred production route using very highly enriched (and very expensive) 123 Te target (cf. Scholten et al., 1989; Mahunka et al., 1996). The 122 Te(d, n) reaction is an alternative method which has been used at a few laboratories to produce high purity 123 I (cf. Sodd et al., 1970; Beyer et al., 1981; Zaidi et al., 1983). The yield of the latter reaction is lower than the yield of the 123 Te(p, n) reaction, but the commer- cially available 122 Te target material is much cheaper than 123 Te even at a higher enrichment level. There are several experimental production yield data on the 122 Te(d, n) 123 I reaction covering dierent energy ranges and beam currents (Sodd et al., 1970; Beyer et al., 1988; Pimentel and Beyer, 1988). Searching for cross section data, however, we found only two exper- imental works. Zaidi and his coworkers measured the cross sections of the 122 Te(d, n) reaction on 96.9% enriched 122 Te up to 35 MeV and the production cross sections of 123 I on natural tellurium up to 14 MeV deu- teron energy in a detailed investigation (Zaidi et al., 1983). Pimentel and Beyer measured the production cross sections of radioisotopes of iodine on natural tellurium up to 14 MeV (Pimentel and Beyer, 1988) and also the production yields and impurity levels on 122 Te enriched to 82.6±93.6% (Beyer et al., 1988). Applied Radiation and Isotopes 50 (1999) 535±540 0969-8043/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved. PII: S0969-8043(98)00059-1 Applied Radiation and Isotopes PERGAMON * IAEA fellow, on leave from Atomic Energy Authority, Nuclear Research Center, Cairo, Egypt { To whom all correspondence should be addressed.