Self-supporting elemental sulfur target for charged particle irradiation

A self-supporting target made of elemental sulfur has been developed for use in vacuum in high energy-resolution measurements at 0° using charged particle beams. The sulfur target is placed on a target ladder that is cooled by liquid nitrogen to minimize its sublimation due to heating by the energy loss of the beam in the target. Sulfur sheets with areal densities of 6–60 mg/cm2 and size of 2×2cm2 are prepared. An energy resolution of 29 keV (FWHM) in the 32S(p,p′)32S(p,p′) experiment at 0° is achieved using a 295 MeV proton beam. The target thickness is stable within ±5% during irradiation with a beam energy loss of 0.2 mW in the target. A windowless sulfur target was used successfully for the first time.