The Hiradmat 27 Experiment: Exploring High-Density Materials Response at Extreme Conditions for Antiproton Production

The HRMT27-Rodtarg- experiment used the HiRadMat facility at CERN to impact intense 440 GeV proton beams onto thin rods -8 mm diameter, 140 length- made of high-density materials such as Ir, W, Ta, Mo among others. The purpose of the experiment has been to reduce uncertainties on the CERN antiproton target material response and assess the material selection for its future redesign. The experiment was designed to recreate the extreme conditions reached in the named target, estimated on an increase of temperature above 2000 °C in less than 0.5 μs and a subsequent compressive-to-tensile pressure wave of several GPa. The goals of the experiment were to validate the hydrocode calculations used for the prediction of the antiproton target response and to identify limits and failure mechanisms of the materials of interest. In order to accomplishing these objectives, the experiment counted on extensive online optical instrumentation pointing at the rod surfaces. Online results suggest that most of the targets suffer important internal damage even from conditions seven times lower than the reached in the AD-target. Tantalum targets clearly showed the best dynamic response.