HESSI SPECTROSCOPY INFO Welcome to the summary guide to HESSI spectroscopy. This file contains assorted information on this subject. DEFAULT ENERGY BINNING SCHEMES - Used for hessi_build_srm and the spectrum object sp_energy_binning parameter. Descriptions of ct_edges.?, where ? = 0: Three energy bands, 10 keV wide, starting from 20 keV. We use it mostly for quick software checks, but it could be useful for some hard x-ray work. 1: 99 1-keV bands, covering 1-100 keV. Possibly good for high-resolution hard-x-ray work (fitting thermal and nonthermal emission, etc.) 2: The three bands from "0" plus 50-100 and 100-200 keV bands; we will probably use this binning for a lot of non-solar work with the rear segments. 3: A broad band from 20-200 keV followed by 6 narrow bands (4 keV wide) to 224 keV. Used in software debugging. 4: 1000 1-keV bands from 3-1003 keV. Mostly useful for generating finely-detailed response matrices for debugging and display purposes. 5: 565 bands: 1 keV each up to 100 keV, then 5 keV bands to 1820 keV, and 10 keV to 2500. In addition, there are sections of fine binning around the 511 keV and 2.2 MeV lines. This is a good choice for first-look spectroscopy of gamma-ray flares. 6: 199 bands: 1 keV binning 1-100 keV, then 5 keV binning to 600 keV. A more complete binning than "1" for studying hard x-ray continuum spectra out to higher energies. 7: 19 bands: 10-keV bands from 10-100 keV, then 50-keV bands to 600 keV. Good for survey work to select spectra for closer analysis with "6". 8: 78 bands: 3-keV bands from 1 to 118 keV, then 15-keV bands up to 703 keV. Intermediate between "6" and "8" in memory use for hard x-ray work. 9: 4 12-keV bands from 200-248 keV. Another debugging mode. 10: 9 bands with pseudo-logarithmic binning covering the whole HESSI energy range. The bin edges are at [3, 6, 12, 25, 50, 100, 300, 1000, 2500, 20000] keV. These spectra should contain all the events in the HESSI data stream (minus any rejected by event selection criteria like segment choices or coincidence rejection). Potentially useful for quick screening to separate x-ray from gamma-ray flares, etc. --------------------------------------------------------------------------- Calling Arguments for Building HESSI Response Matrices Basic Routine is HESSI_BUILD_SRM ; NAME: hessi_build_srm ; ; ; PURPOSE: Provide response matrix for HESSI spectral deconvolution ; ; CATEGORY: HESSI spectral analysis ; ; CALLING SEQUENCE: ; ; hessi_build_srm, ct_edges, use_segment, srm, $ ; /sep_dets, /sep_segs, /use_segco, /use_detco, /astro,$ ; simplify=simplify, atten_state=atten_state, dead_seg=dead_seg, $ ; all_simplify=all_simplify, time_wanted=time_wanted, $ ; earth_position=earth_position,offax_position=offax_position, $ ; integrator=integrator, use_saved=use_saved, make_saved=make_saved, $ ; ph_edges=ph_edges, print_subrms=print_subrms, verbose=verbose, $ ; display_result=display_result, time_it=time_it ; ; INPUTS: ; ; ct_edges If a single number, refers to a particular standard ; binning (these TBD). If a string, will be taken ; to refer to an input file. Otherwise will be a ; (N+1) vector containing boundaries for ; N channels of the counts side of the ; matrices (in that order). If any of the use_saved[]s ; are defined, the binning of that will override ; what is supplied. ; ; use_segment[18] If set, include the corresponding one of 18 ; detector segments ; ; OUTPUTS: ; ; srm Detector response matrices per input photon/cm2 in cnts/cm2/keV ; ; OPTIONAL INPUTS: (ALL INPUT ANGLES IN DEGREES) ; ; /sep_dets if set, return separate matrices for each detector used ; /sep_segs if set, return separate matrices for each segment ; (if /sep_dets set) or else separate sums of fronts and rears ; /use_segco if set, include front/rear coincidence events in the response ; /use_detco if set, include det/det coincidence events in the response ; /astro if set, treat as an astrophysical (out-of-aperture) source ; ; simplify[9] For each submatrix: ; 0 Full calculation of diagonal, off diagonal terms ; 1 Off diagonal terms are an approximation - for most submatrices ; this will mean an average of all segments of the right kind ; (f,r,coinc.) instead of detector-specific results ; 2 Diagonal terms only ; 3 Diagonal terms only, and all = 1 (or zero if ; it's a normally off-diagonal matrix) ; all_simplify If set, overrides individual entries in "simplify" ; Same values. There will be a warning if both are set. ; atten_state Attenuator setting, 0-3 ; dead_seg[18] If set, consider the corresponding one of 18 ; detector segments to be passive ; time_wanted Time of the observation, for purposes of time-varying ; resolution. In seconds from standard time-zero. ; earth_position If a single value, it's a zenith angle, spin ; integrated. If an array of two values, the second ; is the azimuth angle (from spacecraft +x). ; Default is azimuth averaged, zenith=180 (Earth behind). ; offax_position If not called or <=0, assume (solar) source 0.25 deg from ; the z axis. If a single number > 0, use as a single ; radius angle (degrees) and azimuth average. Otherwise ; two numbers, zenith and azimuth angles. ; integrator If a single number, this is an assumed power law index ; over the whole spectrum. If an array, this is a ; model spectrum which must have the ; length n_elements(ph_edges)-1. The distribution of ; counts in each channel will then be by powerlaw fit to ; the model counts on either side. ; use_saved[9] If each is set, it should be set to a filename to ; be read rather than generating that submatrix. ; The 9 submatrices are: ; 0 Grid-pair transmission ; 1 Attenuator transmission ; 2 Blanket transmission ; 3 Det. resp. to modulated photons ; 4 Det. resp. to scattering in 2nd grid and attenuator ; 5 Det. resp. to spacecraft scatter ; 6 Det. resp. to Earth scattering ; 7 Detector intrinsic resolution (w/ radiation damage) ; 8 Detector electronics resolution ; For astrophysical matrices, the first three are zero ; and the fourth contains the full detector response. ; The "perfect" condition for these is: ; [1,1,1,1,0,0,0,1,1] ; Where 1=diagonal, and 0= all zeros. ; make_saved[9] If each is set, it should be set to a filename to ; which the appropriate submatrix will be written. ; ph_edges If a single number, refers to a particular standard ; binning (these TBD). If a string, will be taken ; to refer to an input file. Otherwise will be a ; (N+1) vector containing boundaries for ; N channels of the photon side of the ; matrices (in that order). If any of the use_saved[]s ; are defined, the binning of that will override ; what is supplied. MUST BE EITHER THE SAME AS ; ct_edges (DEFAULT) OR EQUAL TO ct_edges WITH A ; HIGH-ENERGY EXTENSION ; ; print_subrms Print the submatrices to the screen (BEWARE: use ; only for SMALL matrices, and if you're only ; generating one SEGMENT at a time. ; ; verbose Periodic status updates ; ; display_result Plot the final matrix (or matrices) using ; hessi_display_srm ; ; time_it Print system time at the beginning and the end. ;