 |
| Titel |
Development of Standard Samples for on-board Calibration of a New Planetary X-Ray Fluorescence Spectrometer |
| VerfasserIn |
Anne Dreißigacker, Eberhard Köhler, Oliver Fabel, Stephan van Gasselt |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250093258
|
| Publikation (Nr.) |
 EGU/EGU2014-7834.pdf |
|
|
|
|
|
| Zusammenfassung |
| At the Planetary Sciences and Remote Sensing research group at Freie Universität Berlin an
SCD-based X-Ray Fluorescence Spectrometer is being developed to be employed on
planetary orbiters to conduct direct, passive energy-dispersive x-ray fluorescence
measurements of planetary surfaces through measuring the emitted X-Ray fluorescence
induced by solar x-rays and high energy particles.
Because the Sun is a highly variable radiation source, the intensity of solar X-Ray
radiation has to be monitored constantly to allow for comparison and signal calibration of
X-Ray radiation from lunar surface materials. Measurements are obtained by indirectly
monitoring incident solar x-rays emitted from a calibration sample. This has the additional
advantage of minimizing the risk of detector overload and damage during extreme solar
events such as high-energy solar flares and particle storms as only the sample targets receive
the higher radiation load directly (while the monitor is never directly pointing towards the
Sun).
Quantitative data are being obtained and can be subsequently analysed through
synchronous measurement of fluorescence of the Moon’s surface by the XRF-S main
instrument and the emitted x-ray fluorescence of calibration samples by the XRF-S-ISM
(Indirect Solar Monitor).
We are currently developing requirements for 3 sample tiles for onboard correction and
calibration of XRF-S, each with an area of 3-9 cm2 and a maximum weight of 45 g. This
includes development of design concepts, determination of techniques for sample
manufacturing, manufacturing and testing of prototypes and statistical analysis of
measurement characteristics and quantification of error sources for the advanced prototypes
and final samples.
Apart from using natural rock samples as calibration sample, we are currently
investigating techniques for sample manufacturing including laser sintering of rock-glass on
metals, SiO2-stabilized mineral-powders, or artificial volcanic glass.
High precision measurements of the chemical composition of the final samples (EPMA,
various energy-dispersive XRF) will serve as calibration standard for XRF-S.
Development is funded by the German Aerospace Agency under grant 50 JR
1303. |
|
|
|
|
|
|