Development and Improvement Status of Active X-Ray Generators for Future Lunar and Planetary Landing Observations

Abstract

The performance of pyroelectric X-ray generator (PXG) under high vacuum (down to 2.2 × 10^-5 Pa) is investigated with two different gases of dry air and N₂, in order to develop a high-intensity X-ray generator. For both gases, the X-ray intensity decreases for pressures less than 1 × 10^-4 Pa. It is required to control appropriate inner-gas pressure (1 - 10^-3 Pa) to obtain high X-ray intensity, when PXG is used as an active X-ray source for future planetary exploration missions. Furthermore, an analytical system with a carbon nanotube X-ray generator is also discussed for light-element measurement.