Document Reference: Carol G. Maclennan, Lucent Technologies, August 19, 1992

The following document describes the HISCALE analysis program LAN. It is intended for use by the programmers and scientists who are working with the HISCALE data. The reader is assumed to be reasonably familiar with the LAN experiment and its software, including the archive file and analysis routines such as LANSPECT and the IDL software developed by James Tappin (see Appendix 1).

The LAN experiment on Ulysses has four similar detector telescopes which, because of the spinning spacecraft, cover essentially 4p of the sphere (see Figure A2-1 below). The LEMS30 detector points at 30° to the spin axis and is divided into 4 sectors/spin; the LEFS60 and LEMS120 detectors point at 60° and 120°, respectively, to the spin axis and are divided into 8 sectors/spin; and the LEFS150 detector points at 150° and is divided into 4 sectors/spin. The LAN360 program was developed to take advantage of this 360° coverage in all the S/C (spacecraft) planes. A fifth detector telescope, the Composition Aperture (or WART) measures higher Z elements at 60° to the S/C spin axis. An option has been added to plot three WART channels on one page, in a similar format, for the X-Y plane (which is the only plane available for this data).

Figure A2-1 Look angles for the five detector telescopes for the LAN experiment. 

Although the four detector telescopes are similar, they have different energy ranges and geometry factors; in addition the LEMS and LEFS detectors are sensitive to different types of particles. (Tables A2-1 and A2-2 in section A2.2 show the ranges of the channels available.) The LEFS are covered by a foil and the lower four channels are primarily used to measure electrons. The LEMS detectors count mainly protons, but are also sensitive to heavy ions. The LEMS and LEFS differences are discussed further in section A2.5.