Search NASA⌕ Search

SEARCH · Search NASA

Results for “PARTICLE CHARGING”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Acceleration of charged particles in oblique MHD shocks

The motion of high energy charged particles in ideal oblique MHD shocks has been studied extensively. The orbits of charged particles can be solved exactly from Lorentz force equation. It is found that a charged particle may cross the shock front many times before it leaves the shock and it is energized during crossings. The most energetic particles are those with initial pitch and phase near the boundary between crossing and reflected particles. The reflected particles cross the shock about twice as many times as the passing particles do. The energy gain increases for larger values of shock strength and speed. If reflection occurs, the energy gain is larger for smaller angles between the field and shock surface. The introduction of scattering results in a few more higher energy particles.

Chen, G.↗
NASA NTRS2003

Global Aspects of Charged Particle Motion in Axially Symmetric Multipole Magnetic Fields

The motion of a single charged particle in the space outside of a compact region of steady currents is investigated. The charged particle is assumed to produce negligible electromagnetic radiation, so that its energy is conserved. The source of the magnetic field is represented as a point multipole. After a general description, attention is focused on magnetic fields with axial symmetry. Lagrangian dynamical theory is utilized to identify constants of the motion as well as the equations of motion themselves. The qualitative method of Stonner is used to examine charged particle motion in axisymmetric multipole fields of all orders. Although the equations of motion generally have no analytical solutions and must be integrated numerically to produce a specific orbit, a topological examination of dynamics is possible, and can be used, d la Stonner, to completely describe the global aspects of the motion of a single charged particle in a space with an axisymmetric multipole magnetic field.

Shebalin, John V.↗
NASA NTRS1982

Charged particle periodicity in the Saturnian magnetosphere

The present investigation is concerned with the first definitive evidence for charged particle modulations near the magnetic rotation period at Saturn. This periodicity is apparent in the ratios (and spectra) of low energy charged particles in the Saturnian magnetosphere. Most of the data presented were taken during the Voyager 2 outbound portion of the Saturn encounter. During this time the spacecraft was at high latitudes (approximately 30 deg) in the southern hemisphere of the Saturnian magnetosphere. The probe's trajectory was approximately along the dawn meridian at an essentially constant local time. The observation that the charged particle modulation is consistent with the Saturn Kilometric Radiation (SKR) period provides a basic input for the resolution of a puzzle which has existed ever since the discovery of the SKR modulation. The charged particle periodicity identified suggests that a basic asymmetry must exist in the Saturnian magnetosphere.

Carbary, J. F.↗
NASA NTRS2011

Coaxial charged particle energy analyzer

A non-dispersive electrostatic energy analyzer for electrons and other charged particles having a generally coaxial structure of a sequentially arranged sections of an electrostatic lens to focus the beam through an iris and preferably including an ellipsoidally shaped input grid for collimating a wide acceptance beam from a charged-particle source, an electrostatic high-pass filter including a planar exit grid, and an electrostatic low-pass filter. The low-pass filter is configured to reflect low-energy particles back towards a charged particle detector located within the low-pass filter. Each section comprises multiple tubular or conical electrodes arranged about the central axis. The voltages on the lens are scanned to place a selected energy band of the accepted beam at a selected energy at the iris. Voltages on the high-pass and low-pass filters remain substantially fixed during the scan.

Kelly, Michael A.↗
NASA NTRS1992

Charge, energy, and LET spectra measurements of charged particles in P0006 experiment of LDEF

Measurements are under way of the charged particle radiation environment of the LDEF satellite using stacks of plastic nuclear track detectors (PNTDs) placed in different locations of the satellite. In the initial work, the charge, energy, and linear energy transfer (LET) spectra of charged particles were measured with CR-39 double layer PNTDs located on the west end of the satellite. Primary and secondary stopping heavy ions as well as relativistic galactic cosmic rays (mostly iron particles) were measured separately. The results will be compared with similar measurements in other locations on LDEF with different orientation and shielding conditions. The remarkably detailed study of the charged particle radiation environment of the LDEF satellite will lead to a better understanding of the radiation environment of the Space Station Freedom. It will enable more accurate prediction of single event upsets (SEUs) in microelectronics and, especially, more accurate assessment of the risk, contributed by the different components of the radiation field to the health and safety of crew members.

Benton, E. V.↗
NASA NTRS1983

A study of the charged particle calibration requirements for the Deep Space Network

A study made of the Deep Space Network charged particle calibration requirements is discussed. The effects of charged particles on navigation and timing systems were reviewed and it was proposed that a system based upon the Global Positioning System satellites be used to measure the charged particle content of the ionosphere. The system would be required to measure the total electron content of the ionosphere to the order of 10 to the 16th power electron per square meter. Two types of systems were suggested as possible candidates for making these measurements.

Townes, S. A.↗
NASA NTRS1993

LET spectra measurements of charged particles in the P0006 experiment on LDEF

Measurements are under way of the charged particle radiation environment of the Long Duration Exposure Facility (LDEF) satellite using stacks of plastic nuclear track detectors (PNTD's) placed in different locations of the satellite. In the initial work the charge, energy, and linear energy transfer (LET) spectra of charged particles were measured with CR-39 double layer PNTD's located on the west side of the satellite (Experiment P0006). Primary and secondary stopping heavy ions were measured separately from the more energetic particles. Both trapped and galactic cosmic ray (GCR) particles are included, with the latter component being dominated by relativistic iron particles. The results from the P0006 experiment will be compared with similar measurements in other locations on LDEF with different orientation and shielding conditions. The remarkably detailed investigation of the charged particle radiation environment of the LDEF satellite will lead to a better understanding of the radiation environment of the Space Station Freedom. It will enable more accurate prediction of single event upsets (SEU's) in microelectronics and, especially, more accurate assessment of the risk - contributed by different components of the radiation field (GCR's, trapped protons, secondaries and heavy recoils, etc.) - to the health and safety of crew members.

Benton, E. V.↗
NASA NTRS1992

Charged particle LET-spectra measurements aboard LDEF

The linear energy transfer (LET) spectra of charged particles was measured in the 5 to 250 keV/micron (water) interval with CR-39 and in the 500 to 1500 keV/micron (water) interval with polycarbonate plastic nuclear track detectors (PNTDs) under different shielding depths in the P0006 experiment. The optimal processing conditions were determined for both PNTDs in relation to the relatively high track densities due to the long term exposure in space. The total track density was measured over the selected samples, and tracks in coincidence on the facing surfaces of two detector sheets were selected for measuring at the same position on each sheet. The short range (SR) and Galactic Cosmic Ray (GCR) components were measured separately with CR-39 PNTDs and the integral dose and dose rate spectra of charged particles were also determined. The high LET portion of the LET spectra was measured with polycarbonate PNTDs with high statistical accuracy. This is a unique result of this exposure due to the low flux of these types of particles for typical spaceflight durations. The directional dependence of the charged particles at the position of the P0006 experiment was also studied by four small side stacks which surrounded the main stack and by analyzing the dip angle and polar angle distributions of the measured SR and GCR particle tracks in the main stack.

Csige, I.↗
NASA NTRS1975

Effects of opposing voltage and magnetic fields on charged particle motion

The motion of charged particles was examined in the case of a homogeneous magnetic field together with an orthogonal electric field which has a gradient opposing voltage parallel to the electric field. Two regimes result: in one of these, the particles' rate of gyration is changed from the conventional gyrofrequency; in the other, acceleration of the particle takes place. Applied to a plasma, the theory predicts new electric currents orthogonal to magnetic fields.

Cole, K. D.↗