| Gem mounting procedure |
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1. The first step in the assembly of a GEM is to stretch it as
tightly as possible on a mounting frame as shown in this figure. Some
wrinkles on the GEM surface are visible. The framed GEM is put in a oven
at 70C. |
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2. After a 30 minute warming period, the GEM surface is tight, as
shown on this figure.Epotecny E505 epoxy is applied to the G10 frame and a
small drop of conductive epoxy is applied to a contact pad. The G10 frame
is then pressed, epoxy covered
side down, unto the GEM. |
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3. Two thick aluminum compression plates are also warmed to 70C at the
same time
as the GEM. These are pressed on either sides of the GEM as
shown on this figure. The lower plate supports the GEM and stretching
frame, while the upper plate presses against the G10 frame. |
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4. Pressure is then applied to the compression plates using large C
clamps, as shown on this figure. The whole assembly is then inserted in
the oven for 2 hours at 70C. This will allow the Epotecny E505 epoxy to
set. The stretched GEM will then be firmly glued to the G10 frame |
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| GEM and motherboard |
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| 5. The full double GEM structure and Aluminized mylar drift plane is
shown on this figure. |
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6. The first step in disassembly, to modify a gap or replace a
defective GEM, involves the removal of the drift plane. This is shown on
this figure. The top GEM is visible.
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7. This pictures shows the structure with the drift plane and top GEM
removed. The bottom GEM is visible. |
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8. During assembly, cleaning or soldering procedures, the GEM must
always be covered and the gaps sealed, as shown on this figure. These
tasks are
accomplished in the clean room and a full suite, with
masks and powder free gloves, must be worn. Throughout the process, the
parts are examined through a magnifying lens. Dust and beads of solder
must be removed. |
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| Window assembly |
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9. Through discussions with the GDD group at CERN, it was decided that
a non-conductive window should be used. The inside of the GEM box window
frame is shown on this figure.The o-ring groove is visible. The aluminized
mylar window will be removed and replaced with clear mylar. The Epotecny
E505 epoxy, which holds the window, must be machined off.
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10. The new window material is stretched over a "mounting drum" as
shown on the right of this figure. The clean GEM frame window is shown.
The contact area for the window (a 2 cm wide strip around the opening) is
roughed out with sand paper to
provide a better grip for the
epoxy. The drum and mylar are warmed to 70C and then
Epotecny
E505 is applied on the mylar over the area which coincides with the drum
wall. |
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11. The drum is then flipped over, as shown on this figure and pressed
against the window frame. The whole assembly is put in the oven a 70C for
2 hours. Weights are applied on top of the drum. |
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12. Finally, the detector is fully reassembled and a leak test is
perfomed to verify the integrity of the new window. To that aim, P10 is
flowed through the detector and a Matheson flammable gas sniffer is used,
as shown on this figure. |
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| System setup |
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| 13. ALEPH (module on L.H.S.) and HQV810 (module on R.H.S.) are coupled
to the output signal connector on the back of the GEM motherboard, as
shown on this figure.
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14. The completed detector is then mounted inside the X ray box,
approximately centered
horizontally with the X-ray collimator, as
shown on this figure. The drift plane is visible through the clear window.
The red end piece, on the collimator,
holds the 50 micron pin
hole. |
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