The Photoelectron Method for Nonperturbative Diagnostics of a Negative-Ion Beam

The photoelectron method for nonperturbative diagnostics of a negative-ion beam (PEDB) proposed by the author is expounded in detail in this review. In this method, necessary information on the beam is extracted by means of electrons produced as a result of the near-threshold stripping of a negligible part of the ions on the photon target that probes the beam and is formed with the help of laser radiation. For various negative ions, most possibilities of the diagnostics are considered, and the influence of the space charge of the beam on the PEDB is analyzed. Primary attention is given to H- relativistic ions widely employed in accelerator techniques. The multifunctional device developed for realizing the PEDB in a linear area of the transportation channel is described in detail. This device can successfully be used for the nonperturbative diagnostics of the beam of H relativistic ions with a current up to several hundred milliamperes, for example, in neutron sources projected at various scientific centers on the basis of linear accelerators.