Mechanical Properties of the External Beam Window for the PEFP

There are 6 external beam lines among the Proton Engineering Frontier Project's (PEFP's) user facilities. The beam window size for large-area irradiation was determined to have a 300 min diameter and a 0.5 min in thickness and an aluminum-beryllium alloy (AlBeMet) was adopted as the basic material due to not, only its good radiation damage resistance but also its good thermal characteristics. In this work, numerical simulations were conducted to find the proper supporting method for the thin beam window and all O-ring seal was introduced to relieve the concentrated stress. The AlBeMet sheet used in the plastic-forming process for the concave shape was also simulated with the AUTOFORM code. With these results, a pilot beam window was made and tested.