'Integration & Schedule' Session at Ringberg, Feb 13, 2007
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Summary by K.T. Knoepfle, Version 3 of Mar 6, 2007 including
(partially modified) comments by Bela and results from
Infrastructure Meeting at LNGS
Agreement on final Dimensions:
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>>> All numbers need to be confirmed !! <<<
o Superstructure
Adjustment range of lock on superstructure ......................... +-20 mm
Superstructure must be built to this precision.
There will be a cutout in the superstructure floor around the
shutter body (dimensions have been specified by Mr. Ackerman
to Matthias before). At this cutout the clean room floor will
start at 9660 mm directly on the beams.
o Lock
lowest surface of lock flange ...................................... 9935 mm
thickness of horizontal shutter head................................ 180 mm
lowest surface of shutter .......................................... 9755 mm
clean room floor top surface........................................ 9760 mm
superstructure floor top surface ................................... 9700 mm
upper surface of HEB700 & IPE120 beams ............................. 9660 mm
(top of IPE120 beams could be lowered to 9600 mm if needed)
lower surface of IPE120(6) beams between HEB700 beams .............. 9540 mm
o Cryostat
total height ................................................... 8900 - 7 mm
o Water Tank
thickness of bottom of WT.............................................. 7 mm
inner diameter of hole in WT roof .................................. 2000 mm tbd
final height of WT roof @ dia 2000.................................. 8800 mm
thickness of WT flange at dia 2000.................................. tbd
hole circle on WT roof for fixation of interface WT - cryostat ..... tbd
Superstructure
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> A damped fixation of lock on supertructure is not needed w.r.t.
earthquake effects according to Pace seismic report. However,
decoupling of lock from superstructure w.r.t. vibrations should be
considered - even if lock has internal vibrational decoupling already
implemented.
> How to access the manifold and how to transport not too heavy loads
(<250 kg) to the manifold will proposed by MPI-HD.
Cryostat
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(see http://www.mpi-hd.mpg.de/ge76/tg04.html for latest but still
PRELIMINARY drawings).
o Template has been ordered by MPI at German company; shipment to LNGS
will be in week 10.
o Interface to WT: prelim. drawings available
o Guiding bolts need to be discussed between MPI-K and MPP-M
o Mounting of PMT's in skirt: drawing in prep.
o Mounting of reflector foil: drawing in prep.
o Protection during WT building
Protection is needed; minimum plastic foil; better protection also against
mechanical impact.
> MPI will provide possible design.
> Carla will ask WT fab company for opinion/quote.
Water Tank
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o Interface WT - cryostat
> design to be provided by MPI HD; interface material needs to be flexible
and Rn- & light tight; proposed interface material: NEOPRENE.
> Check if this fulfils all requirements
o Location of heat exchanger for exhaust gas: Outside WT only possible if
impact of temperature gradient on WT wall established.
No way to decide that within short time??!
> The 'final decision' to implemented exchanger within WT has been revised
during follow-up meeting at LNGS on Mar 05.
Carla will ask engineers to find out what must be done to mount heat
exchangers outside the WT.
> Responsible for heat exchanger: MPI-HD.
Muon Veto on roof
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> Final configuration/dimensions are needed; enough material is available.
So two layers, each 3cm thick, could be implemented.
Exhaust gas tubes, cryogenic lines. cables, etc...
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> It is agreed that halogen-free cables are used unless there are convincing
reasons for deviating from this agreement.
> All below to be discussed at LNGS on Monday, March 5.
plan for tubes, cryogenic lines, cables,....
dto for respective fixations
feedthrus for cables cleanroom-electronics room
dto for pipes cleanroom-cryogenics room
connection to LNGS ventilation
Electronics Room
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> It is decided that this room should have steel/tin walls but needs not to
be a Faraday cage.
> Layout will be provided by Carla and Bernhard.
> MPI Munich is responsible for building this room together and in the same/similar
technology as the cleanroom.
Grounding Scheme & Implications for Isolation of Cryostat, Lock, ...
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> No isolation of cryostat, lock, etc. foreseen. However, if long tubing from
distant locations can be relativley easy isolated, it should be done.
> All electric lines including the electronic ground must enter the lock or
cryostat via isolated flanges.
> WT and cryostat will be well grounded.
> Detailed grounding scheme still lacking.
Cables for Phase 1 (Phase 2) Detectors
--------------------------------------
> Candidate cables for Phase 1 have been identified by Carla.
> Carla will deliver 3x 7m of these cables to Bela for lock tests.
> Cables for Phase 2 have not been discussed.
Carla stresses the need to conduct thorough tests of complete readout
chain using all components including e.g. pogopin contacts.
Installation needed already this year at GERDA Site
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> electric power, pressurized air, scaffolding : all available
> LN2 .........................................: line to be implemented
> exhaust gas line ............................: forgotten to be discussed
> protective wall in front of LVD..............: provided by LNGS
Coverage of Superstructure Tender
---------------------------------
The tender covers the steel structure, walls, doors, and floors.
> All the rest including in particular electrical installation and
other utilities have to be acquired in addition.
> Detailed list of these items including their priority needed.
Location of LN2 and LAr Storage Tanks
-------------------------------------
> Integral concept needed for GERDA and GERDA Detector Lab.
> To be discussed in March 5 meeting.
> At present, it is assumed that LAr 5.0 qualitydoes meet all our purity specs.
Radon Reduction Unit
--------------------
There is no consens on the need for such a unit. - It is pointed out that the clean
room specs depend quite a bit on the question if the use of Rn reduced air is
indispensable in the cleanroom. Alternatively, it is considered to operate the clean-
room without Rn reduced air and to use clean benches that are purged with pure N2.
> The decision on the Radon Reduction Unit has been postponed.
> If costs do allow, the cleanroom should be specified such that its construction is
compatible with and adequate for a later operation with Rn reduced air.
Schedule
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The T_zero for planning the works in Hall A is determined by the delivery of the
cryogenic vessel. Due to a 3 month delay in the production of the vessel heads, this
delivery will be not before September 2007. While schedules for WT, superstructure, and
electronics are available, the time schedule for the installation of the cleanroom and
lock is still being optimized.
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