1. Geometry of the Tracker in the Flight Instrument The following slides present an overview of the geometry of the tracker. Dimensions corresponding to constants in the geometry file are indicated in red italics. Some issues:  There are volumes which I don’t see in the geometry file that should be added to the geometry description. The combination of bias board, glue, and face sheet represent a substantial amount of material (about 0.5% X0), and affects the position of the tungsten and silicon (by about 0.7 mm). I don’t know whether to include them individually or in aggregate. (Maybe they’re in there already!)  Some of the elements have slightly different x and y dimensions. For example, the active area of the wafer is 87.552x87.572 mm. If we intend to use only one number, it’s better to use the one in the measurement direction (the width, rather than the length).

2. Arrangement of Towers in Tracker modWidth 373.5 mm Not to Scale! wallWidth 371.5 mm Stay-Clear 372.0 mm wallGap 1.5 mm Tower Height 617.787 mm

3. 1 Top 11 Standard 4 SuperGlast 2 No-Converter 1 Bottom 0 Arrangement of Trays in a Tower Measures Y 18 A Layer is made up of the top of one tray and the bottom of the next higher tray 19 Trays yield 18 layers. Measures X Etc… Measures X Measures Y Not to Scale!

4. Side View of a Typical Tray in a Tower Tray Silicon Face Sheet Bias Board Tungsten Glue Closeout Core D D, the distance between a the top of one tray and the top of the next tray varies, and is equal to the height of the closeout + spacer post. The spacer is chosen so that the height d is always exactly 2 mm. d = 2.00 mm Ladders “Boss” Boss, closeout and spacer are not part of geometry model d c = 27.92 mm* *Bottom Tray, 33.909 mm Not to Scale!! Wall Spacer post

5. Top View of Tray Face sheet (carbon panel), 360.1 mm Ladder length 358.075 mm Total width of ladders 358.60 mm “Electronics Gap” 4.2 mm Electronics Gap 4.2 mm Wall thickness, 1.5 mm Outside of Tray 371.5 mm (square) Face Sheet 360.1 mm The dimensions of (face sheet+electronics gap) = 368.5, but there is some uncertainty in the actual values, because the closeout wall is complex. Ladder_gap, 0.20 mm Not to Scale!! SSD_gap 0.025 mm

6. Detail of Ladder and SSDs SSD_gap 0.025 mm siWaferSide 89.5 mm (square) SSD active length 87.572 mm siWaferActiveSide 87.552 mm Converter area 87.552 mm (square) Converter is sized to cover active area of SSD

7. Detail of Strips on Wafer SSD pitch 0.228 mm 384 strips/SSD Dead band 0.964 mm Dead band 0.974 mm Strip width 0.056 mm Edge of active area to center of 1 st strip 0.114 mm

8. Details of Top Face of Trays (all trays the same, except top tray) siThick, 0.400 mm Glue, 0.150 mm Bias plane, 0.239 mm Glue, 0.075 mm faceThick, 0.150 mm Not to Scale! Core

9. Details of Bottom Face of Standard Tray, including Bottom Face of Top Tray Silicon, 0.400 mm Glue, 0.150 mm Bias plane, 0.239 mm Glue, 0.750 mm Not to Scale! convThickReg, 0.105 mm Tungsten Core Face sheet, 0.152 mm

10. Details of Bottom Face of SuperGlast Tray Glue, 0.750 mm Not to Scale! Silicon, 0.400 mm Glue, 0.150 mm Bias plane, 0.239 mm convThickSup, 0.630 mm Tungsten Note: Tungsten and Face Sheet are thicker! Core Face sheet, 0.228 mm

11. Details of Bottom Face of No-Converter Tray Silicon, 0.400 mm Glue, 0.150 mm Bias plane, 0.239 mm Glue, 0.750 mm Not to Scale! Core Face sheet, 0.152 mm