Outgassing of TPS pulsed kicker magnets decreased with vacuum firing

Abstract

Two in-vacuum kicker magnets serve to inject and to extract the electron beams for the TPS injector. A large gas load generated from the outgassing of kicker ferrites (CMD5005) causes concern. To study the effect of vacuum firing in decreasing the outgassing from kicker ferrites, we set up a test bench to record spectra from a residual-gas analyzer (RGA) and measured the rates of outgassing during vacuum firing. The RGA spectrum revealed that water vapor is the dominant gas from the unbaked ferrites; with the throughput method the rate of outgassing, q2.7 (Ferrite), before baking was 5.5 × 10−9 mbar L s−1 cm−2. A duration 40 h of vacuum firing at 200 °C is required to remove the water vapor from the kicker ferrites and to yield a rate between 2.2 × 10−12 and 2.6 × 10−12 mbar L s−1 cm−2 after vacuum firing.