摘要:

The interim report of the 1989 NASA Cosmic Ray Program Working Group is presented. The report summarizes the cosmic ray program for the 1990’s, including the recently approved ACE, Astromag, HNC, POEMS, and SAMPEX missions, as well as other key elements of the program. New science themes and candidate missions are identified for the first part of the 21st Century, including objectives that might be addressed as part of the Human Exploration Initiative. Among the suggested new thrusts for the 21st century are: an Interstellar Probe into the nearby interstellar medium; a Lunar‐Based Calorimeter to measure the cosmic ray composition near ∼1016eV; high precision element and isotope spectroscopy of ultraheavy (Z≥30) elements; and new, more sensitive, studies of impulsive solar flare events.

ISSN:0094-243X    

DOI:10.1063/1.39139

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The space missions selected over the past year in response to NASA Announcements of Opportunity include an ensemble of unprecedented particle astrophysics investigations: (1) a polar‐orbiting, Scout‐class Small Explorer mission; (2) a Delta‐class Explorer mission in a halo orbit at the L1 Lagrangian point; (3) a secondary payload on the Earth Observing System polar platform; (4) the Astromag facility on the early Space Station Freedom with three complementary first‐generation investigations; and (5) a fourth Space Station Freedom payload to investigate actinide nuclei. There is a one‐to‐one mapping of these missions with the top priorities of the Cosmic Ray Program Working Group. Carrying them to completion will ensure U.S. preeminence in particle astrophysics well into the first decade of the next century. Investigations made in conjunction with a potential lunar base might provide the next quantum step in the 21st century.

ISSN:0094-243X    

DOI:10.1063/1.39157

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The EPACT experiment will measure abundances, spectra and angular distributions of particles from 20 keV/amu to 500 MeV/amu. At high energies, isotopes will be resolved up throughZ=26, at intermediate energies elements with 1<Z<82 will be observed at at low energies element abundances aboveZ=2 will be resolved for the first time.

ISSN:0094-243X    

DOI:10.1063/1.39137

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The ONR‐604 instrument has been designed to measure the energy spectra and the isotopic composition at 1 AU of the elements Hydrogen to Nickel in the energy range 40–500 MeV/n and will be carried by the Combined Release and Radiation Effects Satellite (CRRES) to be launched July, 1990 in a highly eccentric orbit between a low perigee and a synchronous orbit point. It will measure galactic cosmic rays, solar energetic particles, and trapped and pseudo‐trapped particles in the Earth magnetosphere. Also at 1 AU, the Energetic Heavy Ion Composition (EHIC) instrument, designed to study mainly the elemental and isotopic composition of solar energetic particles over the charge range H to Ni, in the energy range 0.5 to 200 MeV/n, will be placed in a Sun‐synchronous circular polar orbit of 833 or 870 km altitude by a NOAA‐I satellite scheduled to be launched late 1990 or early 1991. The University of Chicago High Energy Telescope (HET) experiment which is part of the COSPIN consortium on the ‘‘Ulysses’’ mission will measure the energy spectra and the isotopic composition of the elments Hydrogen to Nickel in the energy interval 20–450 MeV/n in the heliosphere, both the ecliptic plane and at high heliographic latitudes in an orbit around the Sun that will have an aphelion near a Jupiter orbit point and a perhelion of about 1.4 AU. It will be launched October 1990.

ISSN:0094-243X    

DOI:10.1063/1.39138

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The Solar, Anomalous, and Magnetospheric Particle Explorer, SAMPEX, will carry out energetic particle studies of outstanding scientific questions in the fields of space plasma physics, solar physics, magnetospheric and middle atmospheric physics, and cosmic ray physics. SAMPEX will measure the electron and ion composition of energetic particle populations from ∼0.4 MeV/nucleon to hundreds of MeV/nucleon from a zenith‐pointing small satellite in near‐polar orbit, using a coordinate set of detectors with excellent charge and mass resolution, and with higher sensitivity than previously flown instruments. While over the magnetic poles, the instruments will study the composition of anomalous cosmic rays, solar energetic particles, and galactic cosmic rays. At lower magnetic latitudes, geomagnetic cutoff effects will allow determination of the ionization state of these particles at energies much higher than can be studied from interplanetary spacecraft. At subauroral latitudes, SAMPEX will also observe precipitating relativistic magnetospheric electrons, which undergo important interactions within the middle atmosphere.

ISSN:0094-243X    

DOI:10.1063/1.39140

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The Advanced Composition Explorer (ACE) was recently selected as one of two new Explorer‐class missions to be developed for launch during the mid‐1990’s ACE will observe particles of solar, interplanetary, interstellar, and galactic origins, spanning the energy range from that of the solar wind (∼1 keV/nucleon) to galactic cosmic ray energies (several hundred MeV/nucleon). Definitive studies will be made of the abundance of nearly all isotopes from H to Zn (1≤Z≤30), with exploratory isotope studies extending to Zr(Z=40). To accomplish this, the ACE payload includes six high‐resolution spectrometers, each designed to provide the optimum charge, mass, or charge‐state resolution in its particular energy range, and each having a geometry factor optimized for the expected flux levels, so as to provide a collecting power a factor of 10 to 1000 times greater than previous or planned experiments. The payload also includes several instruments of standard design that will monitor solar wind and magnetic field conditions and energetic H, He, and electron fluxes. We summarize here the scientific objectives, instrumentation, spacecraft, and mission approach that were defined for ACE during the Phase‐A study period.

ISSN:0094-243X    

DOI:10.1063/1.39173

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The POsitron Electron Magnet Spectrometer (POEMS) has been selected to enter definition phase study for flight on one of the Earth Observing System (Eos) polar platforms. Following launch, which could comes as early as 1997, POEMS will measure the critical positron and electron components of the cosmic radiation and utilize this information to trace processes occurring within our geospace environment, in solar flares, in the solar wind, and elsewhere in the galaxy. In addition, POEMS will measure heavier charged particles to complement the electron/positron measurements. With POEMS data we will investigate the origin (primary or secondary) of galactic positrons, study the charge sign dependence of solar modulation over a large fraction of a solar magnetic cycle, measure positron and neutral particle emission from solar flares, and monitor the temporal variations of the charged intensities and energy spectra in the Eos orbit. Two orthogonal charged particle telescopes are used, each terminating in a shared bismuth germanate (BGO) detector array that also serves as a calorimeter for neutral particles, specifically neutrons and gamma‐rays from solar flares.

ISSN:0094-243X    

DOI:10.1063/1.39141

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Two opportunities exist in the next decade for measuring the charge distribution of ultraheavy cosmic ray with unprecedented statistics and elemental resolution. Groups at Berkeley, University of Michigan, and University of Utah will expose an array of track‐recording phosphate glass plates ∼16 m2in area for five years at an orbital inclination of 28.5° on Space Station Freedom. In addition, negotiations are underway between Berkeley and Soviet colleagues to expose 1 to 3 m2of glass for 2 years at an inclination of 51.6° on Space Station Mir. The elemental resolution for the two sets of experiments is expected to be ∼0.25 charge unit. If negotiations are successful, the Mir experiment will be launched in 1991 and will collect about six times as many events with Z≳50 as were studied on HEAO‐3 and about one‐fifth as many events as will be collected on Freedom.

ISSN:0094-243X    

DOI:10.1063/1.39142

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The USA and Italy are planning to place a large superconducting magnet facility, Astromag, on the Space Station Freedom in the late 1990’s. Astromag has been designed as primarily a cosmic ray astrophysics facility, but it could also be used for any investigation which can make use of a large volume, high intensity magnetic field in a microgravity or space environment. This paper describes the facility and mentions the first set of astrophysical problems to be investigated.

ISSN:0094-243X    

DOI:10.1063/1.39143

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The WiZard experiment will utilize the Astromag magnet facility onboard space station Freedom to explore the composition and energy spectra of low‐Z comsic rays. Particular emphasis will be placed on a search for primordial antimatter and measurement of antiproton and positron fluxes at energies up to 400 GeV. In this paper we present the scientific goals and rationale; we describe the experimental method and summarize the present status of the WiZard project.

ISSN:0094-243X    

DOI:10.1063/1.39144

出版商:AIP    

年代:1990

数据来源: AIP