Update on PMMA cathode developments Status Mechanical - electrical - - PowerPoint PPT Presentation

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update on pmma cathode developments
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Update on PMMA cathode developments Status Mechanical - electrical - - PowerPoint PPT Presentation

Apr 06, 2024 26 likes •140 views

Update on PMMA cathode developments Status Mechanical - electrical - optical - operation in TPC mode successfully tested Basic double sided ITO coated units of up to 1x1m 2 feasible Large evaporator for TPB built and commissioned @

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WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Update on PMMA cathode developments

  • Mechanical - electrical - optical - operation in TPC mode — successfully tested
  • Basic double sided ITO coated units of up to 1x1m2 feasible
  • Large evaporator for TPB built and commissioned @ CERN
  • A prototype ITO/PMMA cathode (ton scale LAr TPC) long term test ongoing
  • Cool-down for spring loaded contact test to the ITO surface successful
  • ITO coating quality issue (under investigation with Visiontek)
  • Progress on the conceptual design

Status News

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SLIDE 2

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Cathode for ton scale LAr TPC (ArDM) — tests at CERN

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  • Mechanical robustness during T variation
  • Contact and electrical resistances
  • Contact failures

Aims

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SLIDE 3

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Getting experience with the mechanics - the components

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Electrical contact by spring washers and bolts Mechanical structure Cathode plate

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SLIDE 4

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Arrangement of T-sensors and test contacts to the ITO surface

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1 2 3 5 6 7 9 12 11 10 4 8

Tsens upper Surface Tsens lower Surface CuBe washer

PMMA Plate ITO

CuBe washer Plastic Screw Copper Wire

Spring loaded contacts (CuBe washer) Elastic at low T Non-sparking

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SLIDE 5

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Test cycle

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Cool down, immersing in Lar At TLAr LAr evaporating

  • vernight

Lifting the plate, warm up

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SLIDE 6

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Open cryostat tests at CERN — ETHZ laboratory

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Electrical connections to 12 points on lower ITO surface LAr bath Temperature sensors

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SLIDE 7

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Preliminary results

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At low temperature (87 K), two rings (point 2 and 9) lost contact, (resistances are out of the range) Other resistances look reasonable (not measures with 4-wire method) Contact problem related to mechanical imperfection of holes (not related to ice formation) Resistance V.S. Temperature

100 200 300 400

  • 120
  • 88
  • 55
  • 23

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Resistance V.S. Temperature

500 1000 1500 2000

  • 200
  • 150
  • 100
  • 50
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SLIDE 8

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

ITO coating problems

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Appeared only on 2 surfaces out of 6 Presently under investigation with Visiontek

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SLIDE 9

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Conceptual design

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ITO/TPB coating PMT array Resistive connections ITO coating Resistive connections Plate / PMT units lattice spacing: 0.5 … 1m

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SLIDE 10

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Possible arrangement in WA105

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ITO coated PMMA Plates installed at the Cathode PMT and Cathode structures

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SLIDE 11

WA105 Technical Board meeting 29.6.2016 C.Regenfus ETHZ

Summary / next steps

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Summary

  • Basic R&D finished
  • Company identified capable to provide ITO coatings up to 1 x 1 m2
  • Quality issues to be understood (process) — need to develop QA procedure
  • Conceptual design more or less existing

Plans

  • Continue tests in the 3L cell
  • Long term tests ongoing
  • Developing the mechanical design (ongoing with Adamo)