CDC Construction Details

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Introduction

This page provides links to the documentation on the construction of the CDC at Carnegie Mellon University.

Global Documents

The initial CMU Contract Submission contains the contract, the Statement of Work (SOW) and the Technical Review Report. These documents were signed off on by both Jefferson Lab and CMU and the contract for construction started on May 15, 2010. As part of this work, CMU has provided an overall Quality Assurance Plan for the construction of the CDC.

1. GlueX-doc:1438 Contract package - (Feb.2010).
2. GlueX-doc:1619 Quality assurance plan - (Feb. 2010).

Assembly documents

The assembly of the CDC is broken into several phases as outlined in the EVMS system. Within each of these phases are various milestones and test data that needs to be performed. For each of these phases, a preliminary construction plan based on prototype work has been provided as part of the overall CDC Construction Plan. These have been updated with a preliminary plan for each activity which includes information on training, quality assurance and tests. Finally, as each phase is entered, a detailed plan is developed and written in the form of an instruction manual with photographs that details how each step is to be done. These detailed plans are developed in discussion with scientists, the construction manager and the technicians to both minimize the chance for error and optimize the process in terms of reproducibility and time involved.

• Initial checks and chamber frame assembly and alignment.
• Installation of straw tubes in the chamber frame.
• Installation of the internal gas plumbing and the outer chamber shell.
• Stringing of wires in the sraw tubes.
• Installation of the upstream plenum.
• Electrical connections to the chamber.
• Installation of the downstream plenum.
• Chamber performance tests.

1. GlueX-doc:1280 CDC Construction Plan (Feb. 2010).

Parts Acceptance Tests

All parts that go into the the CDC are checked to make sure that they are within design tolerances. If a part is out of tolerance, it is corrected if possible, and rejected if not possible. The parts that have been checked include the end plates, the straw tubes, the donuts which are glued into the straws, feed thrus which hold the straws in the chamber frame and the pin holders which hold the crimp pin in place.

The results of the acceptance checks are generally very good.

Part	Action	Acc. %
Aluminum donuts	extensive reaming	~100%
Plastic donuts
Aluminum feed thrus	extensive reaming	~100%
Plastic feed thrus

1. GlueX-doc:1532 Straw tube acceptance checks (June 2010).
2. GlueX-doc:1533 Donut acceptance checks (April 2010).
3. GlueX-doc:1534 Feed thru acceptance checks (April 2010).
4. GlueX-doc:1626 Pin holder acceptance checks (October 2010).

Frame assembly and alignment

• • CDC Construction Plan
  • Final CDC Drawings
  • End plate Alignment
  • Straw Assembly and Insertion
  • Straw cut and clean
  • Mixing Conducting Epoxy
  • Glue Donuts into straws
  • Install straws in frame
  • Wire String Details
  • Conducting Epoxy Order Schedule
  • Document describing the measurement of wire tensions.
• Q&A Documents
  • Summary of Tests
  • Straw-tube acceptance checks
  • Aluminum Donut acceptance checks
  • Aluminum Feedthru acceptance checks
• Traveler Spreadsheets
  • Glue Log
  • Wire Stringing Log
  • Electrical Hookup Log
• Other Log Files
  • Cleanroom Log Sheet
• Photographs
  • Clean Room
  • Corrosion on the aluminum endplate.