Investigation of (d,x) nuclear reactions on natural ytterbium up to 24 MeV Mayeen Uddin Khandaker a,⇑ , Hiromitsu Haba b , Naohiko Otuka c , Ahmed Rufa’i Usman a a Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia b 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 article info Article history: Received 21 April 2014 Received in revised form 20 May 2014 Accepted 21 May 2014 Keywords: 24-MeV deuteron Stacked-foil activation Deuteron-induced reaction cross-sections Physical thick target yields TENDL-2013 abstract Production cross-sections of the nat Yb(d,x) 169,170,171,172,173,174m,174,176m,177g Lu and 169,175,177 Yb reactions have been measured from a 24-MeV deuteron energy down to their respective thresholds by using a stacked-foil activation technique combined with high resolution c-ray spectrometry. Our new experi- mental data extended the experimental database toward the lower energy region for 169 Yb, 171 Lu, 172 Lu, and 176m Lu, and the higher region for 174 Lu, 176m Lu, and 177 Yb. An overall good agreement is found with some of the earlier measurements, whereas a partial agreement is obtained with the theoretical data extracted from the TENDL-2013 library. The (d,p) channel contribution underestimated by the TENDL- 2013 library is successfully reproduced in the global renormalization by Ignatyuk for the FENDL-3.0 library. The production cross-sections of 175 Yb available in the literature were revised based on the latest c-ray intensity adopted in 2004. Physical thick target yields for the investigated reaction products were also deduced and compared with the directly measured ones in the literature. The derived thick target yields for 173 Lu and 174g Lu are higher than the directly measured ones by Dmitriev et al. at 22 MeV. The deduced yield curves indicate that a low energy (<11 MeV) cyclotron and a highly enriched 176 Yb target could be used to obtain 177g Lu with negligible impurity from 177m Lu. Ó 2014 Elsevier B.V. All rights reserved. 1. Introduction Ytterbium (Yb), a rare earth metallic element, finds growing applications in material science and nuclear technology. It can be alloyed with stainless steel to improve some of its mechanical properties [1], used as a doping agent in fibre optic cables [2], in making lasers [3], in ceramic industry [4], in dentistry [5], and used for the production of medically and technologically important radionuclides [6–10]. Therefore, an accurate knowledge of activation cross-sections of ytterbium isotopes is indispensable for various practical applications in science and technology. Several radiolanthanides such as 177 Lu, 172 Lu, 169 Yb, and 175 Yb, produced via neutron or charged-particles irradiations on various rare earth targets, find increasing applications in internal radiotherapy and imaging procedures. Among them, 177g Lu, a mixed b  and c emitter, is widely used in many clinical procedures due to its excellent decay characteristics (T 1/2 = 6.647 d; E max b  ¼ 498:3 keV, I total b  ¼ 100%; E c = 112.9498 keV, I c = 6.17%; E c = 208.3662 keV, I c = 10.36%). The emission of b  particles makes it ideal in targeted radiotherapy applications [11,12], and then the emissions of low energy photons facilitate simultaneous scintigra- phy and dosimetry studies without posing any extra radiation dose to the patients, i.e., in vivo tracking of the therapeutic dose [13]. Its half-life is long enough to allow sophisticated preparation (e.g., shipping, labelling, purification etc.) for use without any significant loss of activity. 177 Lu can be produced in principle in several ways. Currently, a large scale production of 177 Lu is in prac- tice by using only the high flux nuclear reactor via the direct 176 Lu(n,c) 177 Lu or indirect 176 Yb(n,c) 177 Yb ? 177 Lu routes followed by a complex separation procedure of 177 Lu from the Yb isotopes [14]. On the other hand, the carrier-free 177 Lu is available in the charged-particle irradiations on various targets, though its activity is relatively lower than those in the reactor productions [6–8,15–17]. However, it may be possible to overcome this deficiency with recent high-power accelerator technologies, which enable large scale and on-site productions of 177 Lu leading to its various practical applications. The long shelf-life of the generator system of 172 Hf (T 1/2 = 1.87 y) ? 172 Lu (T 1/2 = 6.07 d) is an attractive route to obtain 172 Lu in pure form [18]. 172 Lu was proposed to be used as a radio- tracer in compound labelling and animal biodistribution studies http://dx.doi.org/10.1016/j.nimb.2014.05.020 0168-583X/Ó 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +60 1115402880. E-mail address: mu_khandaker@um.edu.my (M.U. Khandaker). Nuclear Instruments and Methods in Physics Research B 335 (2014) 8–18 Contents lists available at ScienceDirect Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb