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.
Similar content being viewed by others
References
Arnaud, M. and Rothenflug, R.: 1985, ‘An Updated Evaluation of Recombination and Ionization Rates’, Astron. Astrophys. Suppl. Ser. 60, 425.
Baker, D. N., Mason, G. M., Figueroa, O., Colon, G., Watzin, J. G., and Aleman, R. M.: 1993, ‘An Overview of the Solar, Anomalous, and Magnetospheric Particle Explorer Mission’, IEEE Trans. Geosci. Remote Sens. 31, 531.
Fisk, L. A., Kozlovsky, B., and Ramaty, R.: 1974, ‘An Interpretation of the Observed Oxygen and Nitrogen Enhancements in Low-Energy Cosmic Rays’, Astrophys. J. 190, L39.
Gloeckler, G., Geiss, J., Roelof, E. C., Fisk, L. A., Ipavich, F. M., Ogilvie, K., Lanzarotti, L. J., von Steiger, R., and Wilken, B.: 1994, ‘Acceleraton of Interstellar Pickup Ions in the Disturbed Solar Wind Observed on Ulysses’, J. Geophys. Res. 99, 17637.
Gloeckler, G., Bedini, P., Bochsler, P., Fisk, L. A., Geiss, J., Ipavich, F. M., Cain, J., Fischer, J., Kallenbach, R., Miller, J., Tums, O., and Winner, R.: 1998, ‘Investigation of the Composition of Solar Wind and Interstellar Matter Using Solar Wind and Pickup Ion Measurements with SWICS and SWIMS on the ACE Spacecraft’, Space Sci. Rev. 86, 497.
Hovestadt, D. et al.: 1978, ‘The Nuclear and Ionic Charge Distribution Particle Experiments on the ISEE-1 and ISEE-C Spacecraft’, IEEE Trans. Geosci. El. GE-16, 166.
Hovestadt, D., Gloeckler, G., Höfner, H., Klecker, B., Fan, C. Y., Fisk, L. A., Ipavich, F. M., O'Gallagher, J. J., and Scholer, M.: 1981, ‘Direct Observation of Charge State Abundances of Energetic He, C, O, and Fe Emitted in Solar Flares’, Adv. Space Res. 1, 61.
Hovestadt, D., Klecker, B., Höfner, H., Scholer, M., Gloeckler, G., and Ipavich, F. M.: 1982, ‘Ionic Charge State Distribution of Helium, Carbon, Oxygen, and Iron in an Energetic Storm Particle Enhancement’, Astrophys. J. 258, L57.
Hovestadt, D., Gloeckler, G., Klecker, B., and Scholer, M.: 1984, ‘Ionic Charge State Measurements During He+-Rich Solar Energetic Particle Events’, Astrophys. J. 281, 463.
Hovestadt, D. et al.: 1995, CELIAS-Charge, Element and Isotope Analysis System for SOHO, in: The SOHO Mission, Solar Phys. 162, 441.
Jokipii, J.R.: 1986, ‘Particle Acceleration at the Termination Shock 1. Applications to the Solar Wind and the Anomalous Component’, J. Geophys. Res. 91, 2929.
Klecker, B., Hovestadt, D., Gloeckler, G., Ipavich, F. M., Scholer, M., Fan, C. Y., and Fisk, L. A.: 1984, ‘Direct Determination of the Ionic Charge Distribution of Helium and Iron in 3He-Rich Solar Energetic Particle Events’, Astrophys. J. 281, 458.
Klecker, B. et al.: 1993, ‘HILT: A Heavy Ion Large Area Proportional Counter Telescope for Solar and Anomalous Cosmic Rays’, IEEE Trans. Geosci. Remote Sens. 31, 542.
Klecker, B. et al.: 1995, ‘Charge States of Anomalous Cosmic-Ray Nitrogen, Oxygen, and Neon: SAMPEX Observations’, Astrophys. J. 442, L69.
Luhn, A., Klecker, B., Hovestadt, D., Gloeckler, G., Ipavich, F. M., Scholer, M., Fan, C. Y., and Fisk, L. A.: 1984, ‘Ionic Charge States of N, Ne, Mg, Si, and S in Solar Energetic Particle Events’, Adv. Space Res. 4, 161.
Luhn, A., Klecker, B., Hovestadt, D., and Möbius, E.: 1987, ‘The Mean Ionic Charge of Silicon in 3He-Rich Solar Flares’, Astrophys. J. 317, 951.
Lutz, G., Buttler, W., Bergmann, H., Holl, P., Hosticka, B. J., Manfredi, P. F., and Zimmer, G.: 1987, ‘Low Noise Monolithic Front End Electronics’, MPI-PAE Report, Exp. El. 170.
Mason, G. M. et al.: 1991, ‘The Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX)’, Adv. Space Sci.
Mason, G. M., Reames, D. V., Klecker, B., Hovestadt, D., and von Rosenvinge, T. T.: 1986, ‘The Heavy Compositional Signature in 3He Solar Particle Events’, Astrophys. J. 303, 849.
Möbius, E., Hovestadt, D., Klecker, B., Scholer, M., Gloeckler, G., and Ipavich, F. M.: 1985, ‘Direct Observation of He+ Pick-up Ions of Interstellar Origin in the Solar Wind’, Nature 318, 426.
Mullan, D. J. and Waldron, W. L.: 1986, ‘Ionic Charge States of Solar Energetic Particles: Effects of Flare X-Rays’, Astrophys. J. 308, L21.
Pfeffermann, E. et al.: 1987, ‘The Focal Plane Instrumentation of the ROSAT Telescope’, SPIE 733, 519.
Reames, D. V.: 1990, ‘Energetic Particles from Impulsive Solar Flares’, Astrophys. J. 73, 235.
Reames, D. V.: 1992, ‘Particle Acceleration in Solar Flares: Observations’, in G. P. Zank and T. K. Gaisser (eds.), Particle Acceleration in Cosmic Plasmas, AIP Conf. Proc. 264, 213.
Stone, E. C., Frandsen, A. M., Mewaldt, R. A., Christian, E. R., Margolies, D., Ormes, J. F., and Snow, F.: 1998a, ‘The Advanced Composition Explorer’, Space Sci. Rev. 86, 1.
Stone, E. C., Cohen, C. M. S., Cook, W. R., Cummings, A. C., Gauld, B., Kecman, B., Leske, R. A., Mewaldt, R. A., Thayer, M. R., Dougherty, R. L., Grumm, R. L., Milliken, B. D., Radocinski, R. G., Wiedenbeck, M. E., Christian, E. R., Shurman, S., and von Rosenvinge, T. T.: 1998b, ‘The Solar Isotope Spectrometer (SIS)’, Space Sci. Rev. 86, 357.
Stone, E. C., Cohen, C. M. S., Cook, W. R., Cummings, A. C., Gauld, Kecman, B., Leske, R. A., Mewaldt, R. A., Thayer, M. R., Dougherty, R. L., Grumm, R. L., Milliken, B. D., Radocinski, R. G., Wiedenbeck, M. E., Christian, E. R., Shurman, S., Trexel, S., von Rosenvinge, T. T., Binns, W. R., Dowkonn, P., Epstein, J., Hink, P. L., Klarmann, J., Eijowski, M., and Oletich, M. A.: 1998c, ‘The Cosmic Ray Isotope Spectrometer (CRIS)’, Space Sci. Rev. 86, 283.
Va'vra, J.: 1986, Review of wire chamber aging, Proc. of Wire Chamber Conf., Vienna.
Williams, D. R., McEntire, R. W., Schlemm II, C., Lui, A. T. Y., Gloeckler, G., Christon, S. P., and Gliem, F.: 1994, ‘Geotail Energetic Particles and Ion Composition Instrument’, J. Geomag. Geoelectr. 46, 39.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Möbius, E., Kistler, L., Popecki, M. et al. The Solar Energetic Particle Ionic Charge Analyzer (SEPICA) and the Data Processing Unit (S3DPU) for SWICS, SWIMS and SEPICA. Space Science Reviews 86, 449–495 (1998). https://doi.org/10.1023/A:1005084014850
Issue Date:
DOI: https://doi.org/10.1023/A:1005084014850