gerda detector mounting

Majorana collaboration meeting, Seattle, Aug.7 - Aug. 9

Béla MajorovitsGERDA detector mounting

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GERDA Detector Mounting

• The Detector Holders

• Detector Handling and Transport Infrastructure

• Clean Room

• Lock System Functionality

• Pogo Pin Contacts

OUTLINE:

Béla MajorovitsMax Planck Institut für Physik,

München, Germany



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GERDA Mission Statement

Popularity of the name GERDA in norway 1880 - 2000

Taken from www.norskenavn.no

2020



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GERDA detector holder: phase I



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GERDA detector holder: phase II

Material balance: •31g Cu,•7g Teflon, •2.5 g Kapton cable

Novel low mass contacting scheme with Cu on Kapton.

Low mass holder is suitable for 20 kg load at LN temperature

I. Abt. et al, NIM A 577(2007)574,

nucl-ex/0701004

Immersing of string into lN without substantial movement within reasonable time



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GERDA detector handling

Minimize risk of damage by touching:

Design allows for touch free transport, mounting and dimounting into test stands and into experiment

Easy to move: just like drinking coffee

Easy to store: just like cooking your goulash



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GERDA Detector Transport

Maximum safety for necessary journeys envisioned Use same system as for most precious thing transported in cars:

System successfully tested: prototype-detector safely transported from Mainz to Munich



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Detector array

Liquid argon

Cryostat (steel + Cu)

Water tank (steel)

Muon veto (Č)

GERDA

Lock systemClean-room

Load detectors from top of the tank through clean room area



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GERDA: the clean room

Class 10.000 clean room

Underneath flow boxes class 100

Detector storage

Test stand

Air shower

Material lock

Mounting station



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Cable Arms

Service Flanges

Space for pumping stations

Circular shutter body

Magnetic transfer arms

The Clean Room and the Lock

Inner lock



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The Lock

Rectangular shutters

Signal Feedthroughs as close to the cable arms as possible.

Outer lock

Magnetic transfer arms



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Detector Integration: Rail system

Magnetic transfer arm

Wheel gear

Cable car

Rail toward outer lock



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Loose pulleysliding on a guiding rail

Cable winch

Overhead pulleyStrain relief

HV and signal cables,Steel cables holding the detectors

Ge-crystals

Side view

Total length between overhead pulley and final crystal position: ~7m

Two steel cables to have a fixed angle position of crystal relative to vertical axis

33mm

Detector Integration: Rail system



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Detector Integration: String Pulley

It is tricky to bring down strings without any torsion--> use torsion resistent guide chain (Kabelschlepp) made of stainless steel

Electrical motor drives the winch



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Towards overhead

pulley

Towards crystal

Contacting Within the Lock

Pogo pin contacts

NiAu plated copper pad surface

Laser welded connection to cables to outside world

Kapton cable towards front end electronics



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Conclusion

• Due to external requirements: very tricky mechanisms

• Technical solutions for all processes exist

• Technical realization well under way

• Only little and only screened materials used (stainless steel and Teflon)

• There will come a time when we can relax and the name GERDA will be popular again



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Phase II storage infrastructure

Pressure gauge

Safety valve

Flow controller to exhaust line

Exhaust line

Flushing line

Towards Pumping line

Detector storage system built at MPI Munich for our prototype detectors.

gerda detector mounting

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