Search NASA⌕ Search

Engineering topics

Anderson, V.

Publications and source records attributed to Anderson, V..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Solar Particle Events at Mars Seen by MARIE, 2002-2003

The MARIE detector aboard the 200 1 Mars Odyssey operated continuously between March 13, 2002, and October 28, 2003. During these twenty months, approximately 12 periods of enhanced solar particle activity were observed. The last of these, on October 26-28, 2003, caused the instrument to lose communication with the spacecraft. In addition to that very large event, several other major Solar Particle Events (SPEs) were observed. Those prior to March 2003 have been discussed elsewhere [I] and will be reviewed here. Many of the solar events seen at Mars correspond well to observations by GOES and ACE satellites near Earth. Some SPEs were observed by MARIE when Mars was on, or near, the opposite side of the sun as seen from Earth; and while a few of them - most notably the large full-halo Coronal Mass Ejections of July 2002 - coincided with events seen by the near-Earth satellites, others were not seen at Earth. Conversely, in this same time period, some SPEs were seen at Earth but not at Mars. Subsequent to February 2003, three SPEs were observed by MARIE, on March 18- 20, May 28 - June 3, and Oct. 26-28. Observations of solar energetic particles at Mars can be combined with data from other points in the heliosphere from, e.g., the Solar Heliospheric Observatory, ACE/CRIS, and GOES satellites near Earth, and Ulysses. Having several different observation points is useful for testing models of CME initiation and propagation.

Cleghorn, T.↗
NASA NTRS2004

Update on the Status of the FLUKA Monte Carlo Transport Code

The FLUKA Monte Carlo transport code is a well-known simulation tool in High Energy Physics. FLUKA is a dynamic tool in the sense that it is being continually updated and improved by the authors. Here we review the progresses achieved in the last year on the physics models. From the point of view of hadronic physics, most of the effort is still in the field of nucleus--nucleus interactions. The currently available version of FLUKA already includes the internal capability to simulate inelastic nuclear interactions beginning with lab kinetic energies of 100 MeV/A up the the highest accessible energies by means of the DPMJET-II.5 event generator to handle the interactions for greater than 5 GeV/A and rQMD for energies below that. The new developments concern, at high energy, the embedding of the DPMJET-III generator, which represent a major change with respect to the DPMJET-II structure. This will also allow to achieve a better consistency between the nucleus-nucleus section with the original FLUKA model for hadron-nucleus collisions. Work is also in progress to implement a third event generator model based on the Master Boltzmann Equation approach, in order to extend the energy capability from 100 MeV/A down to the threshold for these reactions. In addition to these extended physics capabilities, structural changes to the programs input and scoring capabilities are continually being upgraded. In particular we want to mention the upgrades in the geometry packages, now capable of reaching higher levels of abstraction. Work is also proceeding to provide direct import into ROOT of the FLUKA output files for analysis and to deploy a user-friendly GUI input interface.

Pinsky, L.↗
NASA NTRS2004

Space Applications of the FLUKA Monte-Carlo Code: Lunar and Planetary Exploration

NASA has recognized the need for making additional heavy-ion collision measurements at the U.S. Brookhaven National Laboratory in order to support further improvement of several particle physics transport-code models for space exploration applications. FLUKA has been identified as one of these codes and we will review the nature and status of this investigation as it relates to high-energy heavy-ion physics.

Anderson, V.↗
NASA NTRS2003

Visualization of Radiation Environment on Mars: Assessment with MARIE Measurements

For a given GCR (Galactic Cosmic Ray) environment at Mars, particle flux of protons, alpha particles, and heavy ions, are also needed on the surface of Mars for future human exploration missions. For the past twelve months, the MARJE (Martian Radiation Environment Experiment) instrument onboard the 200J Mars Odyssey has been providing the radiation measurements from the Martian orbit. These measurements are well correlated with the HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations during these specific GCR environment conditions are now extended and transported through the CO2 atmosphere onto the Martian surface. These calculated pa11icle flux distributions are presented as a function of the Martian topography making use of the MOLA (Mars Orbiter Laser Altimeter) data from the MGS (Mars Global Surveyor). Also, particle flux calculations are presented with visualization in the human body from skin depth to the internal organs including the blood-forming organs.

Saganti, P.↗