A detector for ions in a mass spectrometer is to be investigated in which ions are accelerated to high energy and then permitted to strike a metal surface where they produce secondary electrons. The electrons are then accelerated to a scintillator where they produce photons which actuate a closed photomultiplier tube. This type of detector is known as a Daly Doorknob detector when the photons are in the visible region. The present work addresses the possibility of using a scintillator that produced photons in the far UV rather than the visible spectrum. In this case, the photomultiplier need not have a photodynode with a low work function and its attendant thermal emission noise. Previous experiments on UV photon counters suggest certain materials as potential scintillator in the far UV. These will be tested and, if promising, be built into a Daly Doorknob configuration. Comparison of sensitivity and noise level of this detector with a conventional open channeltron detector would be made.
