Results on intense beam focusing and neutralization from the neutralized beam experiment

We have demonstrated experimental techniques to provide active neutralization for space-charge dominated beams as well as to prevent uncontrolled ion beam neutralization by stray electrons. Neutralization is provided by a localized plasma injected from a cathode arc source. Unwanted secondary electrons produced at the wall by halo particle impact are suppressed using a radial mesh liner that is positively biased inside a beam drift tube. We present measurements of current transmission, beam spot size as a function of axial position, beam energy and plasma source conditions. Detailed comparisons with theory are also presented

Drift compression of an intense neutralized ion beam

Longitudinal compression of a velocity-tailored, intense neutralized K{sup +} beam at 300 keV, 25 mA has been demonstrated. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity ramp that longitudinally compresses the neutralized beam, enhancing the beam peak current by a factor of 50 and producing a pulse duration of about 3 ns. This measurement has been confirmed independently with two different diagnostic systems

A THIN COLUMN OF DENSE PLASMA FOR SPACE-CHARGE NEUTRALIZATION OF INTENSE ION BEAMS

Typical ion driven warm dense matter experiment requires a plasma density of 1014/cm3 to meet the challenge of np > nb, where np, and nb are the number densities of plasma and beam, respectively. Plasma electrons neutralize the space charge of an ion beam to allow a small spot of about 1-mm radius. In order to provide np > nb for initial warm, dense matter experiments, four cathodic arc plasma sources (CAPS) have been fabricated, and the aluminum plasma is focused in a focusing solenoid (8T field). A radial plasma probe with 37 collectors was developed to measure the radial plasma profile inside the solenoid. Initial results show that the plasma forms a thin column of diameter ~;7mm along the solenoid axis. The deformation of the magnetic field due to eddy currents, the magnetic mirror effect and plasma condensation are under investigation. Plasma data and ion beam neutralization will be presented

Salinity resistance in Zea mays: fluxes of potassium, sodium and chloride, cytoplasmic concentrations and microsomal membrane lipids

Cytoplasmic concentrations, fluxes of K+, Na+ and Cl and microsomal membrane lipids were investigated in a salt-sensitive and salt-resistant variety of Zea mays. The salt resistance of Protador relative to LGH (salt-sensitive) appears to be related to higher K+ fluxes and cytoplasmic concentrations, and lower Na+ and Cl fluxes and cytoplasmic concentrations, when grown in NaCl. There were no apparent differences in the simple chemical composition of root microsomal membrane lipids between the two varicties, neither were these affected by salt