urn:esa:psa:context:instrument:uly.hiscale-lems 1.0 1.20.0.0 Product_Context HISCALE LEMS 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 Low-Energy Magnetic Spectrometer Charged Particle Detector not applicable not applicable Instrument Overview =================== (adapted from: Lanzerotti, et al. 1992) The are Low-Energy Magnetic Spectrometers (LEMS) provide pulse-height-analyzed single-detector measurements with active anticoincidence. 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 individual LEMS telescopes are referred to as LEMS 30, and LEMS 120, where the number indicates the inclination of the telescope axis with respect to the spacecraft spin axis. The MF, M' F', and BC detector pairs (Tab. 1) are identical (for ease of replacement pre-flight); each consists of two equal 200 micrometer thick, totally depleted silicon surface barrier detectors. The orientations of the telescope axes are such that there is nearly a complete 41r coverage of the unit sphere during one complete spacecraft spin. In the LEMS 30 and 120 telescopes, electrons with energies below ~300 keV are swept away from detectors M and M' by a rare-earth magnet. The geometric factor for the ions measured by detectors M and M' is ~ 0.48 cm2sr. The ion energy channels are listed in Table 1 (the energy channels for both LEMS telescopes are essentially identical). In the LEMS 30 telescope, the magnetically-deflected electrons are counted by a separate detector B, with a geometrical factor of ~0.05 cm2sr. The electron energy channels for B with their defining logic are shown in Table 1. Two-dimensional particle ray tracing in a magnetic field similar to that of LEMS 30 is shown in Figure 7. -Such two-dimensional (and similar three-dimensional) computer ray-tracing studies have been used together with calibration data obtained with a particle accelerator to determine the effective field-of-view of the telescope aperture. TABLE 1. LEMS detector systems. Accum. time(s) Channel Logic Passband[a] Sectors @ 1024 bit/s --------------------------------------------------------------------------------------- LEMS 30[b] Pl M1M2F 50-73 ke V ions 4[b], 8[c] 3[b], 1.5[c] (M,F) P2 M2M3F 73-112 keV ions 4[b], 8[c] 3[b], 1.5[c] LEMS 120[c] P3 M3M4F 112-180 keV ions 4[b], 8[c] 3[b], 1.5[c] (M',F') P4 M4M5F 180-310 keV ions 4[b], 8[c] 3[b], 1.5[c] P5 M5M6F 310-550 keV ions 4[b], 8[c] 6[b], 3[c] ~ 0.48 cm2 sr P6 M6M7F 550-1500 keV ions 4[b], 8[c] 6[b], 3[c] P7 M7M8F 1.0-1.8 MeV ions 4[b], 8[c] 6[b], 3[c] P8 M8F 1.5-5.0 MeV ions 4[b], 8[c] 6[b], 3[c] LEMS 30 DEl Bla B2 C 30-50 keV electrons 4 6 (B,C) B1b B2 C 40-50 keV electrons 4 6 ~ 0.05 cm2 sr DE2 B2 B3 C 50-90 keV electrons 4 6 DE3 B3 B4 C 90-165 keV electrons 4 6 DE4 B4 B5 C 165-300 keV electrons 4 6 --------------------------------------------------------------------------------------- [a] The passbands given here are provisional and subject to refinement as in-flight calibrations arc completed. [b] Sectors and accumulation times designated with b are associated with the LEMS 30 system. [c] Sectors and accumulation times designated with c are associated with the LEMS 120 system. 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.