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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2004

Nuclear Physics in Space: What We Can Learn From Cosmic Rays

Studies and discoveries in cosmic-ray physics and generally in Astrophysics provide a fertile ground for research in many areas of Particle Physics and Cosmology, such as the search for dark matter, antimatter, new particles, and exotic physics, studies of the nucleosynthesis, origin of Galactic and extragalactic gamma-ray diffuse emission, formation of the large scale structure of the universe etc. In several years new missions are planned for cosmic-ray experiments, which will tremendously increase the quality and accuracy of cosmic-ray data. On the other hand, direct measurements of cosmic rays are possible in only one location on the outskirts of the Milky Way galaxy and present only a snapshot of very dynamic processes. It has been recently realized that direct information about the fluxes and spectra of cosmic rays in distant locations is provided by the Galactic diffuse gamma-rays, therefore, complementing the local cosmic-ray studies. A wealth of information is also contained in the isotopic abundances of cosmic rays, therefore, accurate evaluation of the isotopic production cross sections is of primary importance for Astrophysics of cosmic rays, studies of the galactic chemical evolution, and Cosmology. In this talk, I will show new results obtained with GALPROP, the most advanced numerical model for cosmic-ray propagation, which includes in a self-consistent way all cosmic-ray species (stable and long-lived radioactive isotopes from H to Ni, antiprotons, positrons and electrons, gamma rays and synchrotron radiation), and all relevant processes and reactions.

Moskalenko, Igor V.↗
NASA NTRS1985

The International Cometary Explorer mission to comet Giacobini-Zinner

The International Cometary Explorer (ICE), scheduled to pass the tail of Comet Giacobini-Zinner on September 11, 1985, was expected to address first-order questions bout the interaction between solar wind and comets. Since ICE was not initially intended for comet studies, it did not have sun-sensitive imaging instruments designed to image the comet nucleus. In effect, ICE was free to pass through the tail of the comet. The ICE spacecraft, a 16-faceted cylindrical drum just over five ft high with a spin axis normal to the ecliptic plane, was designed to encounter the comet at a distance of 0.47 AU from the earth. Scientific instruments on board the spacecraft include: (1) the electron plasma experiment, (2) the vector helium magnetometer, (3) the plasma wave experiment, (4) the radio waves experiment, (5) the plasma ion experiment, (6) the low-energy cosmic ray experiment, and (7) the energetic protons experiment. Targeting error was expected as a result of solar-wind induced plasma tail wagging. Comet interception was planned to be at a distance of 10,000 km from the nucleus.

Von Rosenvinge, T. T.↗
NASA NTRS1973

Pioneer-10 measurements of the differential and integral cosmic-ray gradient between 1 and 3 AU

The cosmic-ray experiment on Pioneer has provided measurements of the differential radial gradient of cosmic-ray helium nuclei between 1 and 3 AU. Upper limits are quoted between 10 and 500 MeV/nuc which are everywhere 25%/AU and in some cases substantially smaller. The integral proton gradient ( 56 MeV) was also measured and found to have the following values: 2.4 + or - 0.3%/AU (1-2 AU), 7.6 + or - 0.7%/AU (2-3 AU).

Teegarden, B. J.↗
NASA NTRS1975

Adaptation of an existing cosmic ray ionization spectrometer experiment to Spacelab

This paper examines the technique of adapting an existing experiment to a Shuttle sortie mission. A sample cosmic-ray balloon experiment was studied to determine the feasibility of this cost-saving technique, which is applicable to a large spectrum of existing experiments, and to determine the programmatic impact and key problems. The main areas investigated include the determination of required modifications, steps in integration to the Spacelab/Shuttle, and the impact on orbital support and operations. One of the main problems in equipment adaptation is the acoustical loading during Shuttle boost; an environmental cover design presented herein shows a potential method to attain the required acoustic attenuation.

Alvarado, U. R.↗
NASA NTRS1992

Some results of the oxidation investigation of copper and silver samples flown on LDEF

The Long Duration Exposure Facility (LDEF) Mission provides a unique opportunity to study the long term effects of the space environment on materials. The LDEF has been deployed in orbit on 7 April 1984 by the shuttle Challenger in an almost circular orbit with a mean altitude of 477 km and an inclination of 28.5 degrees. It was retrieved from its decayed orbit of 335 km by the shuttle Columbia on 12 January 1990 after almost 6 years in space. The LDEF is a 12-sided, 4.267 m diameter, and 9.144 m long structure. The experiments, placed on trays, are attached to the twelve sides and the two ends of the spacecraft. The LDEF was passively stabilized with one end of the spacecraft always pointing towards the earth center and one of the sides (row 9) always facing the flight direction. The materials investigated originate from the Ultra-Heavy Cosmic Ray Experiment (UHCRE). The main objective is a detailed study of the charge spectra of ultraheavy cosmic-ray nuclei from zinc to uranium and beyond, using solid-state track detectors. Besides the aluminium alloy used for the experiment, UHCRE comprises several other materials. The results of space exposure for two of them, the copper grounding strips and the thermal covers (FEP Teflon/Ag/Inconel) painted black on the inner side (Chemglaze Z306), are presented.

Derooij, A.↗
NASA NTRS1985

The isotopic composition of cosmic ray calcium

Data from the high energy cosmic ray experiment on the international sun earth explorer 3 (ISEE-3) spacecraft have been used to study the isotopic composition of cosmic ray calcium at an energy of approx. 260 MeV/amu. The arriving calcium is found to consist of (32 + or - 6)%. A propagation model consistent with both the light and the subiron secondary element abundances was used for the interpretation of the observed calcium composition. The measured 42Ca+43Ca+44Ca abundance is consistent with the calculated secondary production, while the 40Ca abundance implies a source ratio of 40Ca/Fe = (7.0 + or - 1.7)%.

Krombel, K. E.↗
NASA NTRS1985

A model for the proton spectrum and cosmic ray anisotropy

The problem of the origin of the cosmic rays is still uncertain. As a theory, it should explain the support of particles and energy, the mechanism of acceleration and propagation as well as some important features obtained directly from cosmic ray experiments, such as the power spectrum and the knee. There are two kinds of models for interpreting the knee of the cosmic ray spectrum. One is the leaky box model. Another model suggests that the cut-off rigidity of the main sources causes the knee. The present paper studies the spectrum and the anisotropy of cosmic rays in an isotropic diffuse model with explosive discrete sources in an infinite galaxy.

Xu, C.↗
NASA NTRS2007

The Ultimate Monte Carlo: Studying Cross-Sections With Cosmic Rays

The high-energy physics community has been discussing for years the need to bring together the three principal disciplines that study hadron cross-section physics - ground-based accelerators, cosmic-ray experiments in space, and air shower research. Only recently have NASA investigators begun discussing the use of space-borne cosmic-ray payloads to bridge the gap between accelerator physics and air shower work using cosmic-ray measurements. The common tool used in these three realms of high-energy hadron physics is the Monte Carlo (MC). Yet the obvious has not been considered - using a single MC for simulating the entire relativistic energy range (GeV to EeV). The task is daunting due to large uncertainties in accelerator, space, and atmospheric cascade measurements. These include inclusive versus exclusive cross-section measurements, primary composition, interaction dynamics, and possible new physics beyond the standard model. However, the discussion of a common tool or ultimate MC might be the very thing that could begin to unify these independent groups into a common purpose. The Offline ALICE concept of a Virtual MC at CERN s Large Hadron Collider (LHC) will be discussed as a rudimentary beginning of this idea, and as a possible forum for carrying it forward in the future as LHC data emerges.

Wilson, Thomas L.↗
NASA NTRS1983

A large area experiment to determine cosmic ray isotopic abundances

Measurements of the isotopic composition of cosmic rays have shown that the cosmic ray isotope ratios, Ne-22/Ne-20 and (Mg-25 + Mg-26)/Mg-24, exceed the solar abundance ratios by factors of 2.7 and 1.8, respectively. There are several processes which could be responsible for the observed excess of neutron-rich isotopes. The considered models imply neutron enrichment in the case of other, less abundant species, and a measurement of the involved isotopic abundances could provide a basis for the determination of the dominating processes occurring in cosmic ray sources. However, an experiment utilizing special equipment is necessary to conduct the required measurements. Such an experiment, the Aluminum Isotopic Composition Experiment (Alice), is being designed in a joint effort involving NASA and a West German university. Alice uses a Cherenkov-range technique to determine the isotopic composition of elements from oxygen through argon.

Mauger, B. G.↗
NASA NTRS1993

Anuradha and low-energy cosmic rays

After critically reviewing observational results obtained by astronomical spacecraft in the interplanetary medium for several aspects of galactic cosmic rays (GCRs) and anomalous cosmic rays (ACRs), attention is given to spacecraft data gathered in the magnetosphere and a detailed description is given of the Anuradha cosmic-ray experiment carried by Spacelab-3. The Anuradha results discussed concern the orbit average flux and ionization state of ACRs, the origins of partially ionized galactic cosmic-ray sub-Fe and Fe ions, and the significance of enhanced abundance ratios of sub-Fe and Fe ions in GCRs inside the magnetosphere.

Biswas, S.↗
NASA NTRS1974

Measurements of cosmic ray trajectories with a proportional counter hodoscope

A 50 by 50 cm, 8-layer multiwire proportional counter hodoscope has been developed for performing trajectory measurements in a large geometrical factor cosmic ray experiment. The hodoscope has a nominal position accuracy of 0.5 cm and a 1-deg angular accuracy. Data obtained from a balloon exposure show tracks of heavy cosmic rays are efficiently recovered from the copious triggers due to secondary electrons through the use of two discriminators on each wire. The spatial distribution of counts produced by secondary electrons from the iron group nuclei is compared with calculations of energy deposition from the secondaries.

Parnell, T. A.↗
NASA NTRS1994

Observations of enhanced sub-iron (Sc-Cr) to Iron abundance ratios in the low energy galactic cosmic rays in Spacelab-3 and their implications

The Anuradha cosmic ray experiment in Spacelab-3, flown in the orbit at 350 km with an inclination of 57 deg for about six days, was used to measure the low energy galactic cosmic ray (GCR) heavy ions using a specially designed CR-39 detector module incorporating the arrival time information of the particles. The abundances of sub-iron (Sc-Cr) and iron particles in the low energy interval of 30-300 MeV/N were determined from the measurements made in four different depths of the Cr-39 detector module of 150 layers. From these studies we obtained sub-iron (Sc-Cr) to iron abundance ratios of 0.8 to 1.2 in 30-300 MeV/N energy range. It is found that these ratios are enhanced by a factor of two as compared to interplanetary ratios of about 0.5. It is shown that the enhancement of the ratio inside the earth's magnetosphere is probably due to the degree of ionization of low energy Sc to Cr and Fe ions in the galactic cosmic rays and to the rigidity filtering effects of the geomagnetic field. Further studies are needed to understand fully the phenomena and their implications.

Biswas, S.↗
NASA NTRS2000

Charge Detector for the Imaging Calorimeter for ACCESS (ICA)

NASA's Advanced Cosmic Ray Experiment for the Space Station (ACCESS) Mission is planned to consist of a transition radiation detector (TRD) and a thin ionization calorimeter. In order to measure the charge of the primary cosmic ray, it is necessary for the calorimeter to have its own charge detector. Silicon detectors are chosen for the charge detector because of their excellent resolution, small size and nearly square shape. Monte Carlo simulations are performed to find the probability of misidentifying protons as alpha particles due to backscattered radiation from the calorimeter. Simulations were also used to investigate identifying primary cosmic rays that fragmented in the TRD before reaching the calorimeter. For this study algorithms have been developed for determining a direction of the core shower in the calorimeter. These algorithms are used to find the approximate location of the primary particle in the silicon detectors. Results show the probability to misidentify the charge depends upon the energy and direction of the primary particles.

Lee, Jeongin↗
NASA NTRS1973

The radiation monitor cosmic X-ray experiment OSO-1

A comprehensive technical description is presented of the Radiation Monitor which is part of the GSFC cosmic X-ray experiment to be flown on the OSO-1 satellite. The theory of operation, fabrication and assembly, and cone angle determination are reported.

Randall, R. F.↗
NASA NTRS1989

Direct electron-pair production by high energy heavy charged particles

Direct electron pain production via virtual photons by moving charged particles is a unique electro-magnetic process having a substantial dependence on energy. Most electro-magnetic processes, including transition radiation, cease to be sensitive to the incident energy above 10 TeV/AMU. Thus, it is expected, that upon establishment of cross section and detection efficiency of this process, it may provide a new energy measuring technique above 10 TeV/AMU. Three accelerator exposures of emulsion chambers designed for measurements of direct electron-pains were performed. The objectives of the investigation were to provide the fundamental cross-section data in emulsion stacks to find the best-fit theoretical model, and to provide a calibration of measurements of direct electron-pairs in emulsion chamber configurations. This paper reports the design of the emulsion chambers, accelerator experiments, microscope measurements, and related considerations for future improvements of the measurements, and for possible applications to high energy cosmic ray experiments. Also discussed are the results from scanning 56m of emulsion tracks at 1200x magnification so that scanning efficiency is optimized. Measurements of the delta-ray range spectrum were also performed for much shorter track lengths, but with sufficiently large statistics in the number of measured delta-rays.

Takahashi, Y.↗
NASA NTRS1978

Experiment definition and integration study for the accommodation of magnetic spectrometer payload on Spacelab/shuttle missions

A super-cooled magnetic spectrometer for a cosmic-ray experiment is considered for application in the high energy astronomical observatory which may be used on a space shuttle spacelab mission. New cryostat parameters are reported which are appropriate to shuttle mission weight and mission duration constraints. Since a super-conducting magnetic spectrometer has a magnetic fringe field, methods for shielding sensitive electronic and mechanical components on nearby experiments are described.

Buffington, A.↗