Study of polycrystalline and single crystal diamond detectors irradiated with pions and neutrons up to 3×10<sup>15</sup> cm<sup>−2</sup>

Polycrystalline CVD (pCVD) diamond detectors are a viable candidate for the innermost tracking layer of experiments at the SLHC, where lifetime fluences are expected to exceed 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">16</sup> particles/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Irradiation data of diamonds in this fluence range are scarce, and mostly rely on high-energy protons. According to recent NIEL simulations radiation damage induced by fast reactor neutrons might be representative of degradation by high energy hadrons. Seven detector-grade pCVD and two single crystal CVD (scCVD) diamond 5times5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> pad detectors (0.5 mm thick) were acquired from Diamond Detectors Ltd. Four pCVDs were irradiated so far, two to fluences of 1, 3, 10 and 30 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> fast n/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at the TRIGA research reactor in Ljubljana, and two to 3.2 and 6.1 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sup> 200 MeV pions/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at PSI. Charge collection was measured with a <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">90</sup> Sr source using fast electronics with 25 ns shaping in a charge sensitive TCT set-up. Effect of pumping (priming) upon long-time exposure to the 37 MBq beta source was studied. Preliminary results of the charge collection measurements are presented and discussed.