Experimental study of the 165 Ho(d, 2n) and 165 Ho(d, p) nuclear reactions up to 20 MeV for production of the therapeutic radioisotopes 165 Er and 166g Ho F. Ta ´rka ´nyi a , A. Hermanne b , S. Taka ´cs a , F. Ditro ´i a , B. Kira ´ly a, * , S.F. Kovalev c , A.V. Ignatyuk c a Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c, Hungary b Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium c Institute of Physics and Power Engineering (IPPE), Obninsk 249020, Russian Federation Received 28 April 2008 Available online 8 June 2008 Abstract The radioisotope 165 Er (T 1/2 = 10.36 h) is a candidate for Auger-electron therapy. The b  -emitting 166g Ho (T 1/2 = 26.83 h) is now being explored for various therapeutic applications. In the frame of our systematic study of charged particle production routes of ther- apeutic radionuclides the excitation functions of the 165 Ho(d, 2n) 165 Er and 165 Ho(d, p) 166g Ho reactions were measured up to 20 MeV by using a stacked foil irradiation technique and X/c-ray spectroscopy. The excitation function of the 165 Ho(d, 2n) 165 Er reaction was mea- sured for the first time while for the 165 Ho(d, p) 166g Ho reaction only a single dataset of earlier measured cross-sections was found. The measured excitation functions were compared to the results of different nuclear reaction model codes. The calculated thick target yield of the 165 Ho(d, 2n) reaction is significantly higher over the optimal energy range than that for the 165 Ho(p, n) reaction investigated earlier by us. The integral yield of the 165 Ho(d, p) 166g Ho reaction is rather low compared to the established 165 Ho(n, c) 166 Ho reaction in a nuclear reactor. Ó 2008 Elsevier B.V. All rights reserved. PACS: 25.45.z; 27.70.+q Keywords: Holmium target; Deuteron irradiation; Excitation function; Cross-section; Therapeutic radioisotope 1. Introduction Radiolanthanides emitting b  particles and Auger- electrons are increasingly applied for radio-therapeutic purposes. The radionuclide 165 Er (T 1/2 = 10.36 h) is a candi- date for Auger-electron therapy that can be produced by var- ious routes in reactors and accelerators but only the latter method can assure the required high specific activity needed for labeling of radiopharmaceuticals. In the frame of a systematic investigation of accelerator production routes of therapeutic radioisotopes we have recently reported new results on the 165 Ho(p, n) 165 Er route [1] describing in detail the decay characteristics of 165 Er and the different application fields. The aim of present work was to perform a detailed study of excitation function of the 165 Ho(d, 2n) 165 Er process and to compare the produc- tion yield with the above mentioned proton induced reac- tion as we proved in several previous studies [2–6] that in the heavy mass region the (d, 2n) process is often more pro- ductive than the (p, n) reaction. This investigation simultaneously allows the study of the excitation function of the 165 Ho(d, p) reaction leading to 0168-583X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2008.05.123 * Corresponding author. E-mail address: kiralyb@atomki.hu (B. Kira ´ly). www.elsevier.com/locate/nimb Available online at www.sciencedirect.com Nuclear Instruments and Methods in Physics Research B 266 (2008) 3529–3534 NIM B Beam Interactions with Materials & Atoms