Simultaneous hydrogen detection with an ERD gas ionization detector

A large solid-angle gas ionization detector is shown to be capable of simultaneous hydrogen detection during heavy-ion elastic recoil detection of heavier elements. Different modes of detection are possible depending on the specific application. These include a transmission-mode in which the primary ion energy and gas-pressure in the detector are optimized for heavy-ion detection and energy loss signals are recorded for each hydrogen recoil. Alternatively, the primary ion energy can be reduced and the gas pressure in the detector increased so that the recoiled protons are fully stopped in the detector. In this case, a conventional total energy signal can be recorded. The transmission mode is shown to be particularly suited to determining the total hydrogen content of thin films, where the emphasis is on optimum mass and depth resolution for the heavy elements, whilst the stopped mode allows simultaneous hydrogen profiling with reasonable depth resolution.