title: Modeling of neutrals in the Linac4 H(-) ion source plasma: hydrogen atom production density profile and Hα intensity by collisional radiative model.
abstract: To control the H(0) atom production profile in the H(-) ion sources is one of the important issues for the efficient and uniform surface H(-) production. The purpose of this study is to construct a collisional radiative (CR) model to calculate the effective production rate of H(0) atoms from H2 molecules in the model geometry of the radio-frequency (RF) H(-) ion source for Linac4 accelerator. In order to validate the CR model by comparison with the experimental results from the optical emission spectroscopy, it is also necessary for the model to calculate Balmer photon emission rate in the source. As a basic test of the model, the time evolutions of H(0) production and the Balmer Hα photon emission rate are calculated for given electron energy distribution functions in the Linac4 RF H(-) ion source. Reasonable test results are obtained and basis for the detailed comparisons with experimental results have been established.
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ohta
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yasumoto
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nishida
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Hatayama
authors.affiliation: CERN, 1211 Geneva 23, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Mattei
authors.affiliation: CERN, 1211 Geneva 23, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Lettry
authors.affiliation: Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sawada
authors.affiliation: Max-Plank-Instutut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Fantz