title: Initial study of the optical spectrum of the ISIS H- ion source plasma.
abstract: The front end test stand is being constructed at the Rutherford Appleton Laboratory, with the aim of producing a 60 mA, 2 ms, 50 Hz, perfectly chopped H(-) ion beam. To meet the beam requirements, a more detailed understanding of the ion source plasma is required. To this end, an initial study is made of the optical spectrum of the plasma using a digital spectrometer. The atomic and molecular emission lines of hydrogen and caesium are clearly distinguished and a quantitative comparison is made when the ion source is run in different conditions. The electron temperature is 0.6 eV and measured line widths vary by up to 75%.
authors.affiliation: ISIS Pulsed Neutron and Muon Source, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, United Kingdom. scott.lawrie@stfc.ac.uk
authors.forename: S R
authors.initials: SR
authors.lastname: Lawrie
authors.forename: D C
authors.initials: DC
authors.lastname: Faircloth
authors.forename: K
authors.initials: K
authors.lastname: Philippe