A review of investigations in the physics and technology of ion sources, developed in the Institute of Nuclear Physics in Novosibirsk is presented. Distinctive features of physical processes and technical characteristics of plasma sources of gaseous ions, negative ion surface-plasma sources, electrohydrodynamic (liquid metal) ion sources are considered. In original design plasma sources, ion beams with a current of up to 90 A and energies 1–30 keV are formed by four-electrode multislit extraction systems from highly ionized, high brightness plasma flux, generated by an high-current arc discharge with a cold cathode in a small cross-section diaphragmed channel, and directed with a magnetic field of a special configuration. Plasma jet expansion for a very low ion temperature (0.1 eV) production is used. In surface plasma sources, the fluxes of negative ions are produced when electrons are captured from the electrode surface at the electron affinity level of sputtered and reflected particles. A discharge of a special type in a gas-cesium mixture with in a thin plasma layer between the negative ion emitter and emission holes is used. A number of versions of SPS with different types of discharges are considered: SPS which operate in pulse mode with H− beam current up to 11 A, with current 0.1 A, and high brightness for accelerators, for continuous mode operation. Specific features of physical processes in electrohydrodynamic (EHD) ion emitters are studied and the technology of production of different ions is worked out. The production of ion beams with high brightness from the dielectric melt in the EHD-emission regime is developed. The dynamics of spontaneous oscillation excitation with a quasidiscrete spectrum in the frequency range of up to 108 Hz, transient processes occurring at the emission disturbances, emission stability at low current, a physical model for calculating the emission surface dimensions, and the evolution of the ion momentum distribution function for the ion motion are studied. The utilization of the designed EHD sources in the ion microscope, in submicromachining and in high voltage accelerators are discussed.

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The next generation of proton colliders that has been contemplated—the Superconducting Super Collider (SSC) in the U.S. and the Large Hadron Collider (LHC) at CERN—will be the first to encounter significant intensities of synchrotron radiation within the cold bore tube of superconducting magnets. Aside from removal of the synchrotron radiation heat load, the main problem encountered is how to deal with the magnitudes of photodesorbed gases. Choosing the beam tube to coincide with the cryosorbing magnet bore tube has the advantages of simplicity and, in principle, of providing very high pumping speed. Tightly bound H, C, and O in the near-surface layer (∼100 Å) are converted by photodesorption to a steadily increasing surface density of physisorbed molecules. However, the effective pumping by the bore tube is greatly reduced by the photodesorption of relatively weakly bound physisorbed molecules. In addition, the saturation vapor density of H2 at the ∼4.2 K temperature of the SSC cryostats exceeds, by a factor of fifty, the upper bound allowed by the nuclear scattering deposition of energy in the magnet cryostats. Consequently, accumulation of a monolayer of physisorbed H2 must be avoided even locally. An alternative approach is to install a coaxial perforated tube or liner inside the magnet bore tube which allows the photodesorbed gases to be pumped out of the view of the synchrotron radiation photons. The purpose of the work described in this paper is to develop a methodology that will allow prediction of the SSC beam tube vacuum for simple, 4.2 K beam tubes and for distributed pump or liner configurations—and to provide the technical data required for choosing among the alternative possibilities. The first photodesorption experiments have been completed on the VEPP2M storage ring at the Budker Institute of Nuclear Physics (BINP). Additional photodesorption experiments are underway at BINP and are being planned for a beamline at the UV ring of the Brookhaven National Laboratory National Synchrotron Light Source (BNL NSLS). Related experiments at BNL measuring molecular sticking coefficients and at the State University of New York-Albany (SUNY-Albany) measuring the depth profile of hydrogen on beam tube surfaces are also beginning to yield data. New ideas for directly measuring molecular density inside a cryosorbing beam tube are under development—neutralization of H− and H+ beams at BINP and positron annihilation at BNL. A status report of these activities is given in this paper.