Areal Thickness of HIPPO Measured by Beam Energy Loss*

HIgh Pressure POint like gas target (HIPPO) is the helium gas target of Strong Gradient Electromagnetic Online Recoil separator for capture Gamma Ray Experiments (St. George). An accurate understanding of the areal thickness of the helium jet in HIPPO is needed to correctly deduce reactions' cross sections studied with St. George. Energy differences of the beam were measured before and after hitting the target. The areal thickness of the jet in HIPPO was then calculated. The thickness calculations suggest that the strongly attenuated beam may have missed the bulk of the helium jet.