Cross sections for production of longer lived 170,168,167Tm in 16 MeV proton irradiation of natEr

Reliable assessment of proton induced production of the long lived radionuclide 170Tm (T1/2 = 128.6 d) on natEr requires optimized irradiation and measurement conditions as only a weak 84.2 keV signal is emitted in its decay. Additional detector shielding helps reducing the contaminating Pb-X rays at that energy. Measuring the excitation function up to 16 MeV, normalized to standard monitor cross sections, and comparison with earlier measured data for 167,168Tm results in new cross section data with reduced uncertainty. Comparison with values predicted by ALICE-IPPE, EMPIRE II and different versions of TALYS (EAF2007 and TENDL2010) shows rather good agreement for these simple (p,xn) reactions.