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Use of an Ultrasonic/Sonic Driller/Corer to Obtain Sample Powder for CHEMIN, a Combined XRD/XRF InstrumentA miniature CHEMIN XRD/XRF (X-Ray Diffraction/X-Ray Fluourescence) instrument is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed in order to enable XRD analysis on an extraterrestrial body is how best to obtain a representative sample powder for analysis. For XRD powder diffraction analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a 2-dimensional detector as used in the CHEMIN instrument will produce good results with poorly prepared powders, the quality of the data will improve if the sample is fine-grained and randomly oriented. An Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL is an effective mechanism of sampling rock to produce cores and powdered cuttings. It requires low axial load (< 5N) and thus offers significant advantages for operation from lightweight platforms and in low gravity environments. The USDC is lightweight (<0.5kg), and can be driven at low power (<5W) using duty cycling. It consists of an actuator with a piezoelectric stack, ultrasonic horn, free-mass, and drill bit. The stack is driven with a 20 kHz AC voltage at resonance. The strain generated by the piezoelectric is amplified by the horn by a factor of up to 10 times the displacement amplitude. The tip impacts the free-mass and drives it into the drill bit in a hammering action. The free-mass rebounds to interact with the horn tip leading to a cyclic rebound at frequencies in the range of 60-1000 Hz. It does not require lubricants, drilling fluid or bit sharpening and it has the potential to operate at high and low temperatures using a suitable choice of piezoelectric material. To assess whether the powder from an ultrasonic drill would be adequate for analyses by an XRD/XRF spectrometer such as CHEMIN, powders obtained from the JPL ultrasonic drill were analyzed and the results were compared to carefully prepared powders obtained using a laboratory bench scale Retsch mill.
Document ID
Acquisition Source
Document Type
Conference Paper
Chipera, S. J.
(Los Alamos National Lab. NM, United States)
Bish, D. L.
(Los Alamos National Lab. NM, United States)
Vaniman, D. T.
(Los Alamos National Lab. NM, United States)
Sherrit, S.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bar-Cohen, Y.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Sarrazin, P.
(NASA Ames Research Center Moffett Field, CA, United States)
Blake, D. F.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Publication Information
Publication: Lunar and Planetary Science XXXIV
Subject Category
Lunar And Planetary Science And Exploration
Distribution Limits
Public Use Permitted.
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