urn:esa:psa:context:instrument:uly.hiscale-ca 1.0 1.20.0.0 Product_Context HISCALE CA HISCALE WART 2023-08-02 1.0 Initial version. urn:esa:psa:context:instrument_host:spacecraft.uly instrument_to_instrument_host Armstrong, T.P., and R. Sahi, Ulysses HISCALE Data Analysis Handbook, Dept. of Physics and Astronomy, Univ. of Kansas, Lawrence, KS, 66045, April 1996. reference.ARMSTRONG-SAHI1996 Armstrong, T.P., Passbands & Efficiencies for LEMS, LEFS and WART Channels, University of Kansas, May 1992. reference.ARMSTRONG1992 Lanzerotti, L.J., R.E. Gold, K.A. Anderson, T.P. Armstrong, R.P. Lin, S.M. Krimigis, M. Pick, E.C. Roelof, E.T. Sarris, G.M. Simnett, and W.E. Frain, Heliosphere instrument for spectra, composition and anisotropy at low energies, Astron. Astrophys. Suppl. Ser. 92, 349-363, 1992. reference.LANZEROTTIETAL1992 Maclennan C.G., and Armstrong T.P., LAN Cover-Close Calibrations, AT&T Bell Laboratories, May 1995. reference.MACLENNAN-ARMSTR1995 Maclennan, C.G., User's Guide to LAN 360, AT&T Bell Laboratories, Aug. 1992. reference.MACLENNAN1992 Tappin, S.J., HISCALE IDL display System (IDL-HS), University of Birmingham, June 1992. reference.TAPPIN1992 Townsend, J.P. Jr., Ulysses Pulse Height Analysis documentation, JHU, Applied Physics Laboratory, July 1990. reference.TOWNSEND1990 HISCALE Composition Aperature Charged Particle Detector not applicable not applicable Instrument Overview =================== (adapted from: Lanzerotti, et al. 1992) The Composition Aperture system (CA; sometimes referred to in the Ulysses project as the "WART") uses a multiparameter detection technique to provide measurements of ion composition in an energy range similar to those of HISCALE LEMS/LEFS. The foil thickness, detector thicknesses, and electronic thresholds were selected to enable the separation of low energy electron and ion fluxes at high sensitivity by comparing detector responses. The Composition Aperature telescope is referred to as CA 60, where the number indicates the inclination of the telescope axis with respect to the spacecraft spin axis. The BC detector pairs consist of two equal 200 micrometer thick, totally depleted silicon surface barrier detectors. The D detector is a thin (5 micrometer) silicon detector of the epitaxial type. The CA telescope uses detectors D and C as an ([Delta]E vs E) telescope, with the B detector operating in anticoincidence. The geometrical factor for the DCB combination is 0.24 cm^2sr. The logic and discrete energy channels for the CA telescope are shown in Table 3. Information from the discrete ion composition channels listed in Table 3 is used in a priority scheme to identify those individual particle events whose energy loss signals in detectors D and Care to be pulse-height-analysed (see below) and included in the telemetry data stream. A rotating four-level priority scheme, shown in Table 4, is used to balance the CA system response to light and heavy ion species. The priority scheme uses the species group analyzed in the immediate previous event in a given sector to establish the relative priorities among the four species groups for the current sector. Thus, if there were an irongroup event analyzed in the immediate previous spin, the fourth column of Table 4 would be operative and shows that the priority order for analysis, from the highest to the lowest priority, would be an event in the oxygen group, the iron group, helium, and protons. Thus, the priority scheme insures that a large number of relatively "rare" ion species will be presented for analysis. In addition to the discrete telescope logic channels that are listed Tables 1-3, the singles counting rates in the individual detectors are monitored and telemetered in a multiplexed mode (Tab. 2). These rates are used as engineering monitors of the instrument performance. These rates can also be used, if required, to make pulsepileup corrections to the coincidence rates. TABLE 3. Ion composition. Accum. time(s) Channel Logic Passband [a] Sectors @ 1024 bit/s CA 60[b] W1 Cl D1 C2 D2 0.35-1.0 MeV protons 8 3 W2 C2 D1 D4 D2 S1 1.0-2.0 MeV protons 8 3 W3 Cl(D2+S1) C3 D3 0.35-1.0 Me V /nuc. He 8 3 W4 C3 D1 Sl C4 D3 1.0-5.0 MeV /nuc. He 8 3 W5 C2 D3 C4 D4 ~ 0.3-1.7 MeV/nuc. C,N,O 8 3 W6 C4 D2 S2 D4 S3 ~ 1.7-10 MeV/nuc. Fe 8 3 W7 C2 D4 C4 ~0.2-1.0 MeV /nuc. Fe 8 3 W8 C4 D3 S3 ~1.0-15 MeV /nuc. Fe 8 3 Z2 >=0.5 MeV, Z>=2 4 6 Z2A >~10.0 MeV, Z>=14 4 6 Z3 >~2.8 MeV, Z>=6 4 6 Z4 >~9.0 MeV, Z>=10 4 6 [a] The passbands given here are provisional and subject to refinement as in-flight calibrations arc completed. [b] Geometrical factor ~0.24 cm^2 sr References ---------- HISCALE References (cited in Armstrong & Sahi, 1996) Curtis, D.W., ISPM/Ulysses LAN Data Processing Software Status, Dec. 1986. Gold R.E., LAN Accelerator Calibration Test Plan, August 1991. Guynn D.R. Jr., LAN Experiment Data System Performance and Interface Specification, June 1992. Kohl, J.W., J.H. Crawford, Calibration of Solar Polar Energy Model LAN-2B Detector Head at GSFC Low Energy Accelerator, July 1986. Simnett, G.M., R.E. Gold, The RTG Background in the LAN Experiment and the Shielding Required to Control It, April 1980. Tappin, S.J., HSIO-HiScale I/O Library, June 1991. Ximenez de Ferran S., Ulysses Spin Reference Pulse, May 1985.