An overview of the new test stand for H− ion sources at FNAL

Abstract

A new test stand at Fermi National Accelerator Laboratory (FNAL) is being constructed to carry out experiments to develop and upgrade the present magnetron-type sources of H(-) ions of up to 80 mA at 35 keV in the context of the Proton Improvement Plan. The aim of this plan is to provide high-power proton beams for the experiments at FNAL. The technical details of the construction and layout of this test stand are presented, along with a prospective set of diagnostics to monitor the sources.

An overview of negative hydrogen ion sources for accelerators

“…Alternatively the ampoule may be heated (to melting point) and cracked inside a secure and inert gas glove box [21], then carefully poured into the oven before being attached to the ion source. Although more difficult and with higher associated risks, this method ensures that no partially-cracked glass blocks the flux of Cs into the ion source [22]. In either method, the oven must be well cleaned and baked out to remove any impurities which could affect the Cs.…”

Overview of recent studies and design changes for the FNAL magnetron ion source

“…A solenoid gas valve used on the Brookhaven National Laboratory BNL, Electron Beam Ion Source EBIS source [7], has been studied on the FNAL test stand [1]. Also a gas valve test stand was built for testing valves with an emphasis on comparing the piezoelectric and solenoid valves.…”

“…As a result of the previous study mass flow controllers were installed on the FNAL test stand as described in [1]. The controllers allow for fine control of gas mixtures and the mixing takes place just before the ion source gas valve.…”

“…The topics include tungsten cathode insert, solenoid gas valves, current controlled arc pulser, cesium boiler redesign, gas mixtures of hydrogen and nitrogen, and duty factor reduction. The studies were performed on the FNAL test stand described in [1], with the aim to improve source lifetime, stability, and reducing the amount of tuning needed.…”

Performance characterization of a solenoid-type gas valve for the H− magnetron source at FNAL

“…These valves are very reliable, however they are affected by changes in ambient temperature, which affect the amount of gas getting into the source, ultimately affecting the source's arc current and beam output. To avoid this issue, a solenoid-operated valve has been tested and characterized in an offline test stand that supports a magnetron source identical to the operational sources [1].…”