Abstract— Thermionic emission performance from single
crystals of CeB6 and LaB6 was investigated at different
operational loads using a test machine, in order to consider CeB6
as a cathode for thermionic RF guns in the future applications.
To evaluate cathode quality and uniformity for long lifetime
applications, Miram curves in conjunction with their associated
practical work function distribution (PWFD) were applied to
the thermionic emission results. The analysis of the PWFD plot
revealed that the variation of the peak in the work function
and full-width at half-maximum for CeB6 is very close to that
of LaB6. This suggests that emission performance, uniformity,
and expected operational lifetime of a CeB6 cathode are comparable
with LaB6 cathodes. In addition, previous simulation results
of the back bombardment (BB) effect on CeB6 and LaB6 emphasized
that CeB6 presents less sensitivity to BB electrons compared
with LaB6 at a 5.5-µs pulse duration and 8-MW RF power. This
gives CeB6 the potential to replace LaB6 as a thermionic cathode
for an RF gun. A complete analysis of the cathode emission
performance and PWFD at different operational loads for
CeB6 prior to a prospective real test is presented.