Effect of in-situ pulse-heating of tantalum anodes on the radiation from bremsstrahlung diodes

Pulse-heating tantalum anodes in bremsstrahlung diodes to >2600 K results in improved bremsstrahlung production. The proton current (from hydrogen impurities) is reduced by more than two orders of magnitude, beam pinching is suppressed, and the far-field dose is increased by 20%. The dose increase is a result of reduced ion current and enhanced electron reflexing through the subrange tantalum foil. A stretching mechanism was used to keep the foil flat and taut during heating. The radiation pattern is symmetric and hollow, producing a more uniform near-field dose distribution than for a pinched beam. This technique can be used to improve X-ray production on high-power generators such as Decade.