[Show abstract][Hide abstract] ABSTRACT: The Solar Energetic Particle Ionic Charge Analyzer (SEPICA) is the main instrument on the Advanced Composition Explorer (ACE)
to determine the ionic charge states of solar and interplanetary energetic particles in the energy range from ≈0.2 MeV nucl−1
to ≈5 MeV charge−1. The charge state of energetic ions contains key information to unravel source temperatures, acceleration,
fractionation and transport processes for these particle populations. SEPICA will have the ability to resolve individual charge
states and have a substantially larger geometric factor than its predecessor ULEZEQ on ISEE-1 and -3, on which SEPICA is based.
To achieve these two requirements at the same time, SEPICA is composed of one high-charge resolution sensor section and two
low- charge resolution, but large geometric factor sections. The charge resolution is achieved by the focusing of the incoming
ions, through a multi-slit mechanical collimator, deflection in an electrostatic analyzer with a voltage up to 30 kV, and
measurement of the impact position in the detector system. To determine the nuclear charge (element) and energy of the incoming
ions, the combination of thin-window flow-through proportional counters with isobutane as counter gas and ion-implanted solid
state detectors provide for 3 independent ΔE (energy loss) versus E (residual energy) telescopes. The multi-wire proportional
counter simultaneously determines the energy loss ΔE and the impact position of the ions. Suppression of background from penetrating
cosmic radiation is provided by an anti-coincidence system with a CsI scintillator and Si-photodiodes. The data are compressed
and formatted in a data processing unit (S3DPU) that also handles the commanding and various automatted functions of the instrument.
The S3DPU is shared with the Solar Wind Ion Charge Spectrometer (SWICS) and the Solar Wind Ion Mass Spectrometer (SWIMS) and
thus provides the same services for three of the ACE instruments. It has evolved out of a long family of data processing units
for particle spectrometers.
Space Science Reviews 01/1998; 86(1):449-495. · 5.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The HILT sensor has been designed to measure heavy ion elemental
abundances, energy spectra, and direction of incidence in the mass range
from helium to iron and in the energy range 4-250 MeV/nucleon. With its
large geometric factor of 60 cm<sup>2</sup> sr the sensor is optimized
to provide compositional and spectral measurements for low-intensity
cosmic rays, i.e., for small solar energetic particle events and for the
anomalous component of cosmic rays. The instrument combines a large-area
ion-drift-chamber-proportional-counter system with two arrays of 16
Li-drifted solid state detectors and 16 CsI crystals. The multi- dE
/ dx - E technique provides a low-background mass
and energy determination. The sensor also measures particle direction.
By combining these measurements with the information on the spacecraft
position and attitude in the low-altitude polar orbit, it will be
possible to infer the ionic charge of the ions from the local cutoff of
the Earth's magnetic field. The ionic charge in this energy range is of
particular interest because it provides unique clues to the origin of
these particles and has not been investigated systematically so
IEEE Transactions on Geoscience and Remote Sensing 06/1993; · 3.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Suprathermal Energy Ionic Charge Analyzer (SULEICA) on AMPTE IRM is an instrument to determine the ionic charge state and mass composition of all major ions from H through Fe for energies of the suprathermal plasma (Â¿5 up to Â¿270 keV/charge) by the use of electrostatic deflection, time-of-flight measurement, and energy analysis in solid-state detectors. With its acceptance fan of 400Â° X 10Â° the instrument scans a field of 360Â° by 40Â° in the satellite spin plane. The data contain counting rate information for the evaluation of absolute particle fluxes, live pulse-height events, and matrix rates for selected ions from on-board processing with a microprocessor.
IEEE Transactions on Geoscience and Remote Sensing 06/1985; · 3.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The ISEE-1 and ISEE-C instruments have been designed to measure the elemental abundances, charge state composition, energy spectra, and angular distributions of energetic ions in the energy range 2 keV/charge to 80 MeV/nucleon and of electrons between 75 and 1300 keV. By covering the energy range between solar wind and low-energy cosmic rays the instrument will fill a gap in the knowledge especially of the nuclear and ionic composition of solar, interplanetary, and magnetospheric accelerated and trapped particles. The instrument consists of three different sensor systems: ULECA is an electrostatic deflection analyzer system with rectangular solid-state detectors as energy determining devices, its energy range is ~3 to 560 keV/charge; the ULEWAT is a double dE/dX versus E thin-window flow-through proportional counter/solid-state detector telescope covering the energy range from 0.2 to 80 MeV/nucleon (Fe); the ULEZEQ sensor consists of a combination of an electrostatic deflection analyzer and a thin-window dE/dX versus E system with a thin-window proportional counter and a positionsensitive solid-state detector. The energy range is 0.4 MeV/nucleon to 6 MeV/nucleon. While the ULECA and the ULEWAT sensors are designed mainly for interplanetary and outer magnetospheric studies, the ULEZEQ sensor will also obtain composition data in the trapped radiation zone. 65 rates and pulse-height data can be obtained with sectoring in up to 16 sectors.
Geoscience Electronics, IEEE Transactions on 08/1978;