Rudolf Rieder - Profile on Academia.edu (original) (raw)

Papers by Rudolf Rieder

An Alpha Proton X-Ray Spectrometer for Mars-96 and Mars Pathfinder

(n,2n) EFFECTIVE CROSS SECTIONS FOR NUCLIDES WITH NEUTRON NUMBERS NEAR THE MAGIC NUMBER 50 AT E/sub n/ approximately 14 Mev

Major and trace elements in lunar material

Apollo 11 fines and rocks major and trace elements data obtained by combined instrumental and neu... more Apollo 11 fines and rocks major and trace elements data obtained by combined instrumental and neutron activation analysis

Determination of hydrogen in surface layers of planetary bodies by means of forward spectrometry

Determination of hydrogen using elastic scattering of H and D by alpha-particles from a Cm-244 so... more Determination of hydrogen using elastic scattering of H and D by alpha-particles from a Cm-244 source. Hydrogen can be determined down to concentrations of less than 0.01 wt%; within a certain range it is even possible to determine the H/D ratio.

Cosmic-Ray Produced Radionuclides in the Barwell and Saint-Séverin Meteorites

Astrophysics and Space Science Library, 1969

The radionuclides 32P, 36Cl, 37Ar, and 39Ar have been determined in separate mineral phases of th... more The radionuclides 32P, 36Cl, 37Ar, and 39Ar have been determined in separate mineral phases of the Barwell and Saint-Severin meteorites. Hence, not only the activities of these isotopes in the bulk sample are known, but the contributions of specific neutron-induced reactions to the total activity can be evaluated as well. The activities in the total meteorite samples are, where comparable, rather lower than normal. Of special interest is the ratio 37Ar/39Ar in metal and a comparison of the 32S(n, p)-produced 32P with the 40Ca(n, α)-produced 37Ar and the 39K(n, p)-produced 39Ar.

Refined data of Alpha Proton X‐ray Spectrometer analyses of soils and rocks at the Mars Pathfinder site: Implications for surface chemistry

Journal of Geophysical Research: Planets, 2003

An extensive recalibration of the Alpha Proton X‐ray Spectrometer (APXS) was performed to improve... more An extensive recalibration of the Alpha Proton X‐ray Spectrometer (APXS) was performed to improve the data evaluation of the Mars Pathfinder (MPF) rock and soil in situ measurements. Many samples and geostandards were measured with an MPF identical spare APXS under simulated Martian atmospheric pressure and low night temperature conditions. Precise calibration curves for major and minor elements were obtained. Using an improved spectral evaluation method for the original MPF spectra, refined and new elemental compositions of the MPF rocks and soils were derived. However, all initial conclusions about soils and rocks remained valid. The MPF soil composition revealed the mafic nature of the surface as inferred from the results of Viking 1 and 2 data. However, the MPF rocks reflect a felsic composition. For all samples, linear correlations of sulphur with all other elements were noticed, reflecting the fact that the rocks were covered with varying degrees of soil, which compared to the...

Journal of Geophysical Research: Planets, 1997

The alpha proton X ray spectrometer (APXS) for the Mars Pathfinder mission is designed to provide... more The alpha proton X ray spectrometer (APXS) for the Mars Pathfinder mission is designed to provide a complete and detailed analysis of chemical elements in Martian soil and rocks near the landing site. The APXS instrument is carried on the Pathfinder Microrover, which will provide transportation to places of interest on the Martian surface. It consists of a complex sensor head, mounted on a simple but sophisticated APXS deployment mechanism (ADM) outside the warm electronics box (WEB) of the Microrover, and the instrument electronics, mounted inside the WEB. The ADM permits the instrument sensor head to be placed against soil and rock samples in arbitrary positions, ranging from horizontal to vertical, in order to perform in situ analysis. The possibility to transport the APXS to an arbitrary location, preselected on Earth, and to perform in situ analysis there, constitutes one of the most exciting aspects of the Pathfinder mission. The principle of the APXS technique is based on thr...

IEEE Robotics & Automation Magazine, 2008

Science, 2004

The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a ... more The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks exhibit coatings and other characteristics that may be evidence for minor aqueous alteration. Any lacustrine sediments that may exist at this location within Gusev apparently have been buried by lavas that have undergone subsequent impact disruption.

Athena Alpha-Proton-Röntgen-Spektrometer (APXS) auf Mars 2003 Rover für chemische Analysen der Marsoberfläche: Bau des APXS-Sensorkopfes, des Alpha-Detektorsystems und Integration des APXS-Gesamtsystems : Schlussbericht zum Vorhaben 50 QM 0014 ; Laufzeit: 01.10.2000 - 31.12.2004

Space Sciences Series of ISSI

As Viking Landers did not measure rock compositions, Pathfinder (PF) data are the first in this r... more As Viking Landers did not measure rock compositions, Pathfinder (PF) data are the first in this respect. This review gives no proof yet whether the PF rocks are igneous or sedimentary, but for petrogenetic reasons they could be igneous. We suggest a model in which Mars is covered by about 50% basaltic and 50% andesitic igneous rocks. The soils are a mixture of the two with addition of Mg-sulfate and-chloride plus iron compounds possibly derived from the hematite deposits.

Cosmic-ray produced radioisotopes in lunar samples from the Sea of Tranquillity

Apollo 11 lunar rocks and fines cosmic ray produced radioisotopes, considering surface exposure t... more Apollo 11 lunar rocks and fines cosmic ray produced radioisotopes, considering surface exposure to high energy component flux

APXS results from the Pathfinder Landing Site

Hematite on the Surface of Meridiani Planum and Gusev Crater

Meridiani Planum was selected as a landing side for the Rover Opportunity because of an indicatio... more Meridiani Planum was selected as a landing side for the Rover Opportunity because of an indication of hematite observed from orbit. Meridiani Planum consists of sorted sands with aeolian features like ripples and desert pavements. In impact craters, a high-albedo layered bedrock is exposed. The soil is a mixture of: (i) fine sand material in the size ranges of 50 to 150 m, (ii) sub-angular, irregular particles of 0.5 to 5 mm size with submillimeter circular voids that are most likely vesicular basaltic fragments, and (iii) spherules with a restricted grain size between 4 and 6 mm. The Mini-TES on board the rover Opportunity identified a hematite signature at distance resulting from mm-sized spherules as determined by the Moussbauer Spectrometer. Small quantities of similar spherules (2 vol. %) were found in rock exposures in Eagle crater and were interpreted as concretions that formed by precipitation from aqueous fluids inside sedimentary rocks. At Gusev crater no hematite was obse...

The Athena Mars Rover Science Payload

The Mars Surveyor missions that will be launched in April of 2001 will include a highly capable r... more The Mars Surveyor missions that will be launched in April of 2001 will include a highly capable rover that is a successor to the Mars Pathfinder mission's Sojourner rover. The design goals for this rover are a total traverse distance of at least 10 km and a total lifetime of at least one Earth year. The rover's job will be to explore a site in Mars' ancient terrain, searching for materials likely to preserve a record of ancient martian water, climate, and possibly biology. The rover will collect rock and soil samples, and will store them for return to Earth by a subsequent Mars Surveyor mission in 2005. The Athena Mars rover science payload is the suite of scientific instruments and sample collection tools that will be used to perform this job. The specific science objectives that NASA has identified for the '01 rover payload are to: (1) Provide color stereo imaging of martian surface environments, and remotely-sensed point discrimination of mineralogical composition...

23. Cosmic-Ray Produced Radio Nuclides in the Bar Well and Saint-Severin Meteorites

The radionuclides s'P, s6CI, "'Ar, and sOAr have been determined in separate mineral... more The radionuclides s'P, s6CI, "'Ar, and sOAr have been determined in separate mineral phases of the Barwell and Saint-Severin meteorites. Hence, not only the activities of these isotopes in the bulk sample are known, but the contributions of specific neutron-induced reactions to the total activity can be evaluated as well. The activities in the total meteorite samples are, where compa rable, rather lower than normal. Of special interest is the ratio ., Ar/" Ar in metal and a comparison of the "S(n, p}-produced 32p with the 40Ca(n, a}-produced" Ar and the '9K(n, p}-produced s9Ar. The 3' Arp'Ar ratio in metal is a direct measure of the intensity ratio of cosmic-ray particles with E;:: 200 MeV in the close vicinity of the earth, to that averaged over many revolutions of the mete oroid. At least in the case of Saint-Severin this ratio is slightly higher than the one obtained from target experiments. 32p and 3. Ar have very different half-lives, w...