1. "Drawer Mechanics - MiniDrawer"
Tilecal upgrade meeting at Stockholm (3-5 June 2013)
François Vazeille
on behalf of Roméo Bonnefoy,
François Daudon, Gilles Magaud, Marc Nivoix, Guy Savinel, Pierre Verdier
 Summary of previous progresses
 New Slider
 New Basket
Slider-Basket assembly
New Patch Panel
First cooling tests
Next tests and first conclusion 1

2. Summary of previous progresses
Validation of the Mini-Drawer concept
from tests at CERN,
in various Tilecal module positions (0°, 45°, 90°)
in agreement with theoretical calculations.
[Tilecal week, 7 October 2011]
Tests at 45°
Validation of the Slider concept
from tests at CERN,
using 3 Tilecal modules at 90°
[Tilecal week, 28 September 2012] 2

3. Machining of the 4 Mini-Drawer mock-ups
to fit the Demonstrator needs
Definition of the envelop
for the electronics
[Tilecal week, 1 February 2013]
Tilecal strategy, from present Clermont-Ferrand prototypes
- Next studies and production of Mini-Drawers given to Bucharest (Bodies)
and Barcelona (Mechanical links, cooling, services, etc.).
- First Patch Panels and whole tooling studies made by Clermont-Ferrand. 3

4. New Slider Old Slider Longer: 1 Girder-Ring more on each side
(Now: 3 and 2)
 Better alignment.
 Less weight on
each Girder-Ring.*
Less matter in the
vertical direction
 More space for the electronics,
in particular at the read-out side.
 More space for the Patch-Panel.
Special holes for the contacts of
the vertical plate with the Finger
using dedicated screws
 Rigidity of the Slider given only by the Finger, and not by the Girder-Rings
 No stress on the Girder-Rings.
* Even though the Slider weight is small: about 5 kg. 4

5. New Basket
As before: used for the transport and for the handling operations
(Insertion/extraction).
Very simple shape (Prototype) and small amount of Al matter
 Easy access to the electronics and to the PMT Blocks (A sliding is requested).
 Small weight: about 5 kg.
- Locking for the transport. 5

6. Slider-Basket assembly
Perfect alignment and
easy sliding of the Mini-Drawers. 6

7. New Patch Panel The dimensions are constrained
by the available space inside
both the Slider and the Basket.
6 holes are already drilled:
4 for the HV supplies
2 for the cooling circuitry.
- Freedom is given for drilling other ones. 7

8. First cooling tests 1. Search of the best working safety
Two concepts were tested and could be looked more (or forgot) by Barcelona.
1. Search of the best working safety
In the present ATLAS Drawers:
cooling tubes in Aluminum,
interconnected with plastic (Polyurethane) tubes giving some flexibility.
Advantage: the best thermal conductivity towards the Drawer body.
Disadvantage: possible corrosion coming from water in contact with other metals.
- Is it possible to use other materials?
2. Possible simplification of the cooling circuitry
 Easier connections and manipulations.
In the present ATLAS Drawers: 2 crossed cooling circuits,
one on each Drawer side (Readout/HV).
- Is it possible to cool only the Readout side (and too the PMT blocks)?
 Good if no HV regulation in the Drawers
and if the electronics is very compact (ASIC). 8

9. (The details will be given in the Note on Mini-Drawers).
Tested set-up
A train of 4 Mini-Drawers.
Cooling circuitry only at the Readout side.
Heating resistors to reproduce the standard working.
Comparison of 2 types of tubes: Aluminum and polyurethane.
No use of Al powder and glue as interface with the Drawer body.
Use of only a single cooling circuit.
Summary of the results
(The details will be given in the Note on Mini-Drawers).
In the same conditions (Water flow, temperature)
 Thermal heat exchanges divided roughly by 2 using Polyurethane tubes:
Dissipated heat of  66 W using Aluminum and  30 W using plastic.
Comment: Not using Al powder and glue deteriorates the heat exchange,
but it is the same for the 2 kinds of tubes.
- At a given water flow, we must increase the thermal exchange area
 Use of 4 plastic tubes in parallel ?
 Use of a bigger pipe, why not having a flat shape ?
 …
Comment: in any cases, the interconnections must stay flexible
 motion of the train of mini-Drawers. 9

10. Next tests and first conclusion
By June , at CERN: new tests of insertion/extraction using
- The new Slider.
- The new Basket.
- The first train of 4 Mini-Drawers (with Patch Panel and internal HV cabling).
at least in the building 175, with a Tilecal module equipped with a Finger,
and possibly in the ATLAS pit … if some Modules are accessible.
 After some modifications (if requested)  Availability of Mini-Drawers.
 Completion of the Note in progress collecting all the results.
 First conclusion: promising solution
Easier handling of electronics and Drawers.
A better safety of operations,
in particular the best way for recovering the Girder alignment from inside
without damaging more the Girder-Rings
Slider + Basket = 10 kg, Mini-Drawer = 21 kg, without effort on the Girder-Rings
<< weight of Standard Basket (10 kg?) + Drawer (42 kg)
with an alignment from outside. 10