Concerning all critical criteria as mentioned above Rh-101 turns out to be a feasible solution: It provides the highest photon flux at the optimum energy and has a half-life which fits well to the mission duration. A reliable and efficient production route has been identified as well. However, a detector system which is only sensitive to the 19 keV gamma radiation from this source has to be employed for this radioisotope. The subsequently listed improvements can be employed to increase the activity to 4 GBq compared to the presented first measurements: Employment of pure Ru-101 target (activity increase by a factor of 6), irradiation at a high-power cyclotron with 50 micro A (factor 50), elongation of irradiation time to 40 d (factor 960), optimization of target thickness and beam energy (factor 3), a radiochemical separation of Rh-101 from the irradiated Ru material would greatly reduce the absorption of the 19 keV line in the sample and allow the generation of an optimum geometrical shape for XRD. Shielding against high energetic gamma-rays is necessary; appropriate shielding measures must be implemented into the design of the instrument. Am-241 would represent another good candidate radioisotope for a XRF experiment. However, the Fe-55 isotope is regarded as completely non-appropriate because the initial photon flux is already two orders of magnitude smaller than that of Rh-101, with 6 keV the photon energy is too low for high-performance XRD and XRF, the short half-life would prohibit a mission to the Saturnian's moons.
Radioisotope Rh-101 as X-ray source for instruments on space missions
Radioisotop Rh-101 als eine Röntgenquelle für Instrumente von Raumfahrtmissionen
2008
8 Seiten, 2 Bilder, 1 Tabelle, 8 Quellen
Aufsatz (Konferenz)
Datenträger
Englisch
Advanced Radioisotope Power Sources for Future Deep Space Missions
British Library Conference Proceedings | 2001
|RADIOISOTOPE ELECTRIC PROPULSION FOR ROBOTIC SCIENCE MISSIONS TO NEAR-INTERSTELLAR SPACE
Online Contents | 1996
|