Peter J. Lindstrom

Auroral-Particle Precipitation and Trapping Caused by Electrostatic Double Layers in the Ionosphere

Interpretation of high-resolution angular distribution measurements of the primary auroral electron flux detected by a rocket probe launched into a visible aurora from Fort Churchill in the fall of 1966 leads to the following conclusions. The auroral electron flux is nearly monoenergetic and has a quasi-trapped as well as a precipitating component. The quasi-trapped flux appears to be limited to a region defined by magnetic-mirror points and multiple electrostatic double layers in the ionosphere. The electrostatic field of the double-layer distribution enhances the aurora by lowering the magnetic-mirror points and supplying energy to the primary auroral electrons.

HIGH RESOLUTION SPECTROMETRY FOR RELATIVISTIC HEAVY IONS

Abstract Several techniques are discussed for velocity and energy spectrometry of relativistic heavy ions with good resolution. A foil telescope with chevron channel plate detectors is described. A test of this telescope was performed using 2.1 GeV/A C 6+ ions, and a time-of-flight resolution of 160 ps was measured. Qualitative information on the effect of foil thickness was also obtained.

Electromagnetic dissociation of relativistic O18 nuclei

Measurements of fragment-production cross sections have been made with 0 projectiles of 1.7 GeV/nucleon incident upon targets of Be, C, Al, Ti, Cu, Sn, W, Pb, and U at the LBL Bevalac. We have found that the enhancement with high-Z targets of cross sections for certain fragments agrees both in magnitude and ZT dependence with the predictions of the electromagnetic-dissociation process, which are based upon the known photonuclear cross sections and classical rel?tivistic virtual-photon theory. We have found as well that factorization of the cross sections for nuclear processes is valid to an accuracy of better than 4~. *This work was supported by the Director, Office of Energy Research, Division of Nuclear Physics of the Office of High Energy and Nuclear Physics of the u.s. Department of Energy under Contract W-7405-ENG-48. This manuscript was printed from originals provided by the author.

Fragmentation of Nitrogen-14 Nuclei at 2.1 Gev per Nucleon

An experiment has been carried out at the bevatron on the nuclear fragmentation of nitrogen-14 ions at an energy of 2.1 billion electron volts (Gev) per nucleon. Because of the near equality of the velocities of the nitrogen-14 beam and the fragmentation products at an angle of 0�, we find it possible to identify the nuclear fragments isotopically.

Charge changing cross sections of relativistic uranium

We report equilibrium charge state distributions of uranium at energies of 962 MeV/nucleon, 437 MeV/nucleon and 200 MeV/nucleon in low Z and high Z targets and the cross sections for U/sup 92 +/ reversible U/sup 91 +/ and U/sup 91 +/ reversible U/sup 90 +/ at 962 MeV/nucleon and 437 MeV/nucleon. Equilibrium thickness Cu targets produce approx. = 5% bare U/sup 92 +/ at 200 MeV/nucleon and 85% U/sup 92 +/ at 962 MeV/nucleon. 7 references, 5 figures.

A facility for calibrations and short experiments with heavy ions at the Bevatron

Abstract Heavy-ion beams at the Lawrence Berkeley Laboratory Bevatron are routinely available for calibration purposes. These beams are very useful to cosmic-ray physicists and others who wish to have empirical evidence indicating their instruments really can identify elements or isotopes. Virtually all isotopes through 16 O can be produced over a wide energy range.

A simple magnetic spectrometer for cosmic ray studies to 300 GV

Abstract In this paper we describe the first balloon-borne cosmic ray experiment incorporating a superconducting magnet. The rigidity measuring apparatus consists of an array of emulsion coated glass sheets mounted in the 10 kG field of a superconducting magnet. The 50 cm 2 -ster experiment has been successfully flown 4 times yielding rigidity spectra to ∼300 GV. The emulsion apparatus is described in detail. Features of the magnet construction and operation are presented. The calibration and data analysis procedures used throughout the experiment are discussed.

Electromagnetic dissociation of relativistic O-18 nuclei

Measurements of fragment-production cross sections have been made with 0 projectiles of 1.7 GeV/nucleon incident upon targets of Be, C, Al, Ti, Cu, Sn, W, Pb, and U at the LBL Bevalac. We have found that the enhancement with high-Z targets of cross sections for certain fragments agrees both in magnitude and ZT dependence with the predictions of the electromagnetic-dissociation process, which are based upon the known photonuclear cross sections and classical rel?tivistic virtual-photon theory. We have found as well that factorization of the cross sections for nuclear processes is valid to an accuracy of better than 4~. *This work was supported by the Director, Office of Energy Research, Division of Nuclear Physics of the Office of High Energy and Nuclear Physics of the u.s. Department of Energy under Contract W-7405-ENG-48. This manuscript was printed from originals provided by the author.

ELECTROMAGNETIC DISSOCIATION OF RELATIVISTIC 18O NUCLEI

Measurements of fragment-production cross sections have been made with 0 projectiles of 1.7 GeV/nucleon incident upon targets of Be, C, Al, Ti, Cu, Sn, W, Pb, and U at the LBL Bevalac. We have found that the enhancement with high-Z targets of cross sections for certain fragments agrees both in magnitude and ZT dependence with the predictions of the electromagnetic-dissociation process, which are based upon the known photonuclear cross sections and classical rel?tivistic virtual-photon theory. We have found as well that factorization of the cross sections for nuclear processes is valid to an accuracy of better than 4~. *This work was supported by the Director, Office of Energy Research, Division of Nuclear Physics of the Office of High Energy and Nuclear Physics of the u.s. Department of Energy under Contract W-7405-ENG-48. This manuscript was printed from originals provided by the author.