; ; This document describes the HESSI shutter design. It also includes a full description ; of all materials in the x-ray path starting at the outermost thermal blankets ; around the collimator tube, to the thermal blankets under the collimator, the beryllium ; windows within and outside the cryostat. ; ;From - Tue Jun 29 14:59:18 1999 from Gordon Hurford ; ;Based on UCB's Dummy Shutter drawings (HSIS212 and 214) and Paul's ;e-mail of 22 June, it would appear that: ; ;1. The 'THICK' shutter (nominal .060") refers to shutter 'A' and defaults to ;OUT on launch and in override mode. ; ;2. The 'THIN' shutter (nominal .015") refers to shutter 'B' and defaults to ;IN. ; ;To avoid confusion, I recommend that we label our attenuator disks ;as A and B accordingly and drop the THIN and THICK designations. ; ;gordon ; ; Here is an email from April 1999 from Paul Turin on the mylar in the X-ray path within the cryostat. ;Richard, ;I think I finally have the correct cryostat blanket info. Blanketing in ;front of the detectors is as following (going in the direction of X-ray ;travel): ; ;Outer shield blankets: ; ;1-mil mylar, VDA 1 side ;1/4-mil mylar, VDA 2 sides ;1/4-mil mylar, VDA 2 sides ; ;1/4-mil mylar, VDA 2 sides ;1/4-mil mylar, VDA 2 sides ; ;1/4-mil mylar, VDA 2 sides ;1-mil mylar, VDA 1 side ; ;Inner shield blanket: ; ;1-mil mylar, VDA 1 side ;8 layers 1/4-mil mylar, VDA 2 sides ;1-mil mylar, VDA 1 side ; ;All netting has cutouts over detectors. ; ;Total material in path = 7.25 mils mylar ;VDA = Vapor-Deposited Aluminum, Angstroms thick ; ; ;Paul Turin ;Space Sciences Lab ;U.C. Berkeley ;pturin@ssl.berkeley.edu ; ; 7.25 mils mylar = .002192 * gm/cm2/mil * 7.25 mils of carbon ; plus ; .001168 * gm/cm2/mil * 7.25 mils of oxygen ; ; at http://www.filmcapacitors.com/dielect.htm ; we find the density of Polyester(Mylar) given as 1.395 ; Using the densities above, ;IDL> print,(.002192+.001168)*1000./2.54 ; 1.32283 ; So we are at least close to a standard value. Whew! ; The filter plus blanket transmisson can be calculated in each of the four states by using ; this file and HESSI_FILTERS() ; For a set of energies, , in keV greater or equal to 3 keV. And where is the ; full path to this file. ; ; For the case of both shutters open, ; Open_Transmission = hessi_filters(emdges,/shutters,shutter_file=file) ; For the case of shutter B(Thin) closed and A(Thick) open, ; Thin_B_Transmission = hessi_filters(emdges,/shutters,/thin, shutter_file=file) ; For the case of shutter B(Thin) open and A(Thick) closed, ; Thick_A_Transmission = hessi_filters(emdges,/shutters,/thick, shutter_file=file) ; For the case of shutter B(Thin) closed and A(Thick) closed, ; Thin_B_plus_Thick_A_Transmission = hessi_filters(emdges,/shutters,/thick, shutter_file=file) ; ;The following is the data structure used to describe all of the elements in the X-ray path. ;The thickness units default is 'cm', although 'mils' is most commonly used. ;Presently, only 'mils' is recognized as an alternative to a blank string. ;The id tag means, 0- fixed in path, 1- part of shutter_10 (Thin/B), 2-part of shutter_01(Thick/A). ; ;hessi_win = { hessi_win5, fraction:fltarr(5), regions:intarr(5), layers: intarr(2), $ ; thickness: fltarr(2), units:'', z:0, id:0} ; Define the fractional areas of 4 regions defining the X-ray path cross-section. ; These are the fractional values seen in the lines defining the material in each layer and segment. ;0.850, .050, .0874, 0.012, 0.0006 ;frac1, frac2, frac3, frac4, frac5 0.833207, 0.0841974, .06975, 0.012011, 0.0008318 ;frac1, frac2, frac3, frac4, frac5 disc9 ;For Blankets, see hessi_blanket.txt ;For Cryostat, see hessi_cryostat.txt ;Shutters ;Shutter 10, Thin shutter B, ;1st region- 15 mils al frac1, frac2, frac3, frac4, frac5, 1, 0, 0, 0, 0 1, 1, 16.0,16.0., mils, 13, 1 ;2nd region is just like first region, 16 mils Al frac1, frac2, frac3, frac4, frac5, 0, 1, 0, 0, 0 1, 1, 16.0,16.0, mils, 13, 1 ;3nd region is thick inner area. 40 mils Al. frac1, frac2, frac3, frac4, frac5, 0, 0, 1, 0, 0, 1, 1, 38.0,38.0, mils, 13, 1 ;4th region- 2.5 mils Al frac1, frac2, frac3, frac4, frac5, 0, 0, 0, 1, 0, 1, 1, 2.0, 2.0, mils, 13, 1 ;5th region- 2.5 mils Al frac1, frac2, frac3, frac4, frac5, 0, 0, 0, 0, 1, 1, 1, 2.0, 2.0, mils, 13, 1 ;Shutter 01, Thick shutter A, ;1st region- 59 mils Al frac1, frac2, frac3, frac4,frac5, 1, 0, 0, 0, 0, 1, 1, 60, 60, mils, 13, 2 ;2nd region- 18 mils Al, inner region is all 20 mils except slits. frac1, frac2, frac3, frac4, frac5, 0, 1, 0, 0,0, 1, 1, 24, 24, mils, 13, 2 ;3rd region- 20 mils Al frac1, frac2, frac3, frac4, frac5, 0, 0, 1, 0, 0, 1, 1, 24, 24, mils, 13, 2 ;4rd region- 20 mils Al frac1, frac2, frac3, frac4, frac5, 0, 0, 0, 1, 0, 1, 1, 24, 24, mils, 13, 2 ;5th region- 4 mils Al over small slit. frac1, frac2, frac3, frac4, frac5, 0, 0, 0, 0, 1, 1, 1, 2, 2, mils, 13, 2 ;Summary of text read into structure hesi_win5 structure. ;** Structure HESSI_WIN5, 7 tags, length=72: ; FRACTION FLOAT Array[5] - fractional area in each of 5 regions ; REGIONS INT Array[5] - 1 indicates region populated with this material. 0 empty. ; LAYERS INT Array[2] - minimum and maximum number of layers ; THICKNESS FLOAT Array[2] - minimum and maximum thickness in UNITS ; UNITS STRING '' - UNITS mils or gmcm2 (gms/square cm) ; Z INT 0 - Z of material ; ID INT 0 - Association ID.