IMPACT: A Substantial Upgrade to the HIPA Infrastructure at PSI

The High Intensity Proton Accelerator complex (HIPA) at the Paul Scherrer Institute (PSI), Switzerland, delivers a 590 MeV CW proton beam with currents of up to 2.4 mA (1.4 MW) to several user facilities and experimental stations. Other than the two spallation targets for thermal/cold neutrons (SINQ) and for ultracold neutrons (UCN), the beam feeds two meson production targets, Target M and Target E, serving particle physics experiments and material research via seven secondary beam lines. IMPACT (Isotope and Muon Production with Advanced Cyclotron and Target technology) aims to expand the infrastructure at HIPA in two ways: by HIMB (High-Intensity Muon Beams), increasing the surface muon rate by a factor 100, and TATTOOS (Targeted Alpha Tumour Therapy and Other Oncological Solutions), producing promising radionuclides for simultaneous diagnosis and therapy of cancer in doses sufficient for clinical studies. HIMB and TATTOOS are located close to each other. HIMB has to fit into the existing main proton beam line towards Target E and SINQ, while TATTOOS will occupy an area in a new, adjacent building using 100 µA protons split from the main beam. TATTOOS will be a perfect complement to the existing radionuclide production at 72 MeV, adding a variety of difficult to produce nuclides at a large scale. For HIMB, the current Target M will be replaced by a four-fold thicker target (Target H) consisting of a graphite wheel optimized for surface muon production. In addition, both muon beam lines are improved regarding their transmission from target to experiment. Care is taken to reduce the losses to an acceptable level in the main existing proton beam line. Installation towards the implementation of IMPACT as new user facility is foreseen from 2027.ISSN:2673-548