H− and D− scaling laws for Penning surface-plasma sources

Abstract

H° temperature and density measurements in a Penning surfaceplasma H− ion source. I. Rev. Sci. Instrum. 61, 424 (1990); 10.1063/1.1141260 H− beam emittance measurements for the Penning and the asymmetric, grooved magnetron surface plasma sources Rev. Sci. Instrum. 53, 405 (1982);

Cesiation in highly efficient surface plasma sources

“…A good thermal contact with high thermoconductive insulators (2) made from AlN will be used for cathode cooling. The plasma plate (5) has large mass and good thermal contact with the cooled anode, as in the BINP Penning discharge CSPS [3,12]. For reproducible cesiation it is important to be able to regularly clean the electrode and to reactivate it by heating to high temperature.…”

“…The fundamental difference between the magnetron and Penning sources is that, in the magnetron, H À ions produced at the cathode are directly extracted, while in the Penning source the ions must undergo a charge-exchange process or scattering on atomic hydrogen to reach the emission aperture since there is no direct path from the cathode to the aperture. Discharge noise can be eliminated in a cesiated Penning SPS by optimizing the magnetic field and gas density or using a small admixture of heavier gas (N 2 in [12]). In this regard, emittance measurements have…”

“…The Penning discharge SPS was invented by Dudnikov in BINP [4]. It has had a long history of development at LANL [8,12,15]. Now it is successfully used at ISIS RAL [16,17] and is under development for the Chinese SNS.…”

“…For further beam transportation, magnetic focusing with partial space-charge neutralization [as in many CSPS (e.g., BNL, ANL, FNAL)], or strong electrostatic focusing (as in the SNS LVSPS, or DC PD SPS at BINP) could be used. For beam chopping that is necessary for injection into synchrotrons, it is possible to use a pulsed transverse electric field parallel to the magnetic field, which is applied between two separated plates of the suppression electrode (12) to deflect beam from the aperture. This possibility was tested in the Fermilab magnetron and was discussed in the report of Moehs [14].…”

Ion Source Choices — An H− Source for the High Intensity Neutrino Source

“…To avoid the high operating temperatures and thermal stresses associated with elevated duty factors active cooling of the ion source is necessary. In the case of surface plasma source (SPS) size scaling may also be used to distribute the heat load [4,5].…”