Performance Characterization of a Solenoid-type Gas Valve for the $H^{-}$ Magnetron Source at FNAL

TL;DR

This paper evaluates a solenoid-type gas valve as a more stable alternative to piezoelectric valves for Fermilab's $H^{-}$ ion sources, demonstrating its effective performance in beam extraction tests.

Contribution

It introduces and characterizes a solenoid gas valve for $H^{-}$ ion sources, addressing temperature sensitivity issues of existing piezoelectric valves.

Findings

Successful extraction of 35 keV $H^{-}$ ion beams using the solenoid valve

Performance correlates with applied voltage and pulse width

Potential for improved stability in ion source operation

Abstract

The magnetron-style $H^{-}$ ion sources currently in operation at Fermilab use piezoelectric gas valves to function. This kind of gas valve is sensitive to small changes in ambient temperature, which affect the stability and performance of the ion source. This motivates the need to find an alternative way of feeding H2 gas into the source. A solenoid-type gas valve has been characterized in a dedicated off-line test stand to assess the feasibility of its use in the operational ion sources. $H^{-}$ ion beams have been extracted at 35 keV using this valve. In this study, the performance of the solenoid gas valve has been characterized measuring the beam current output of the magnetron source with respect to the voltage and pulse width of the signal applied to the gas valve.