QC procedures at Pol'Hi'Tech'

1
QC procedures at Pol.Hi.Tech.

• D.Bettoni, G.Cibinetto, S.Morganti,
• Luca Boni, Alfredo Pagano

Ferrara Workshop May 26, 2003
2
Introduction

• QC procedures at Pol.Hi.Tech. (PHT) have been
  discussed and (almost completely) defined in
  various meetings with the company.
• Test equipment to be supplied partly by INFN,
  must be accepted by the company.
• Acceptance criteria to be defined together with
  PHT.

3
Outline

• General infrastructure
• Barcode labelling
• Inspection of profiles
• Mechanical
• Graphite coating
• Resistivity Measurement
• Inspection of jackets, endcaps, circuit cards
• Gas tightness (leak test)
• Wire check
• Wire-cathode distance measurement
• HV conditioning and plateau measurement
• Long range tests

4
General Infrastructure

• QC data and other relevant information collected
  by hand or, whenever possible, automatically with
  several DAQ stations.
• Labview will be used to write the DAQ software
  and design the interface.
• The DAQ stations will be operated by physicists
  on shift and/or PHT personnel.
• All DAQ stations will be on a wireless LAN.
• The DAQ station output will be simple text files.
• Local production database will be available on
  site.
• Data files will be transferred every day to an
  outside server to be imported in the official
  offsite LST database.

5
DAQ and Test Stations

• Dedicated Stations
• Resistivity measurement
• Tube/Spool association
• HV Conditioning and Plateau
• Long term tests
• 1-2 General purpose station(s)
• Visual Graphite inspection
• Gas tightness
• Wire position
• Capacitance

6
Local Production Database

• Linux chosen as platform
• Relational DB (my SQL, postGREP SQL ...)
• Each Station will send files to a central server
  after each operation
• Server will read files into the DB once a day
• Raw data will be sent outside each day

7
Barcode labelling

• The idea is to use barcode labels to identify the
  relevant parts that make up a tube as well as the
  tube itself.
• Barcodes will also be used to enter the results
  of some QC tests, e.g. the defects found in the
  graphite coating.
• Barcode labels will show also a number, to make
  it easier for the operator to look at.

8
Inspection of Profiles

• Mechanical. All profiles checked by Minadek.
  Profiles checked on a sampling basis by PHT and
  measured in Padova.
• Graphite coating. Visual check. Big defects get
  corrected. Small, acceptable defects recorded
  along with their positions.
• Resistivity measurement. Resistivity on the
  bottom of the profiles will be measured
  automatically by means of a probe. Measurements
  will be taken at 50 cm intervals. Tubes accepted
  if resistivity within a predefined range.
  Acceptance criteria to be defined together with
  PHT.

9
Inspection of parts

• Jackets. Check for mechanical integrity and that
  they have the correct dimensions. Done on a
  sampling basis after production.
• Endcaps. Visual check of electrodes and gas
  inlets to make sure they are in good integrity.
• Circuit cards. Visually check for cold solder
  joints and sharp wire ends. Circuit is then
  checked for proper continuity.
• Parts are cleaned by ultrasound at PHT.

10
Gas Tightness

• Gas leakage test is performed by completely
  submerging the
• tubes in water at 15-20 mbar overpressure. Less
  than 1 small
• bubble per minute is required. Leaking tubes are
  fixed with
• PVC glue if possible and tested again. If
  accepted, the
• information that the tube has been repaired will
  be registered
• and the position in which the repair has occured
  will be
• clearly marked. Tubes exceeding the 1 small
  bubble per
• minute limit will be rejected.

11
Wire check

• Wire quality. A sample of wire at the beginning
  of each new spool will be sent to Princeton to be
  checked (mechanical, diameter, etc.). Track will
  be kept of which wires will be used in each tube.
• Wire position. Possibility being considered to
  measure the wire position by means of a camera.
• Wire connection and tension. Capacitance
  measurement at the end, to make sure everything
  is OK after all the handling etc.

12
HV conditioning, plateau, long range tests

• Two test stations will be set up at PHT one for
  HV conditioning and plateau measurement, one for
  long range tests.
• These tests will be done with the ternary gas
  mixture
• 88 CO2, 9.5 Isobuthane, 2.5 Ar.
• The long range tests will be carried out with the
  tubes in the box which will be used for shipping
  the tubes to the U.S.
• Specifications for the plateau will be defined
  after plateaux are measured on prototypes in
  Ferrara and Princeton.

13
HV conditioning

• 7 day conditioning procedure
• 1 day to flow 6 gas volumes
• 8 hours to 1 day to reach 2500 V.
• 8 hours to 1 day to go from 2500 V to maximum
  voltage.
• Tubes drawing more than 5 ?A will be rejected
• Keep 4 days at maximum voltage. The current drawn
  must not exceed 2 ?A for the first day and 100 nA
  for the remaining 3 days. Tubes failing these
  tests are rejected.
• Long range tests
• Each tube will be kept at the maximum operating
  voltage for a period
• of thirty days, during which the current drawn by
  the tube must not exceed
• 100 nA for more than 5 of the time it is
  monitored. In addition no
• observed activity allowed in the second half of
  the history.

14
Summary

• QC procedure at PHT well defined and agreed upon
  with the company.
• Still a few questions to be addressed.
• Need to purchase equipment to carry out tests at
  PHT.
• Work is beginning to set up the general
  infrastructure and DAQ systems and to design the
  two test stations.