160 likes | 289 Views
Installation and Testing of Optical Harnesses. John Matheson. Rutherford Appleton Laboratory. Schedule for test and assembly Outline of required tests Acceptance testing Assembly to discs Final testing. Schedule for Test and Assembly: Barrel. B3: 64 harnesses B4: 80 harnesses
E N D
Installation and Testing of Optical Harnesses • John Matheson • Rutherford Appleton Laboratory Schedule for test and assembly Outline of required tests Acceptance testing Assembly to discs Final testing
Schedule for Test and Assembly: Barrel • B3: 64 harnesses • B4: 80 harnesses • B5: 96 harnesses • B6: 112 harnesses • B3: 50 days April 02 -> June 02 • B4,B5,B6: Oct 02 -> Mar 03 • delivery -> installation ~35 days • 1 man hour for acceptance test • 2hr for assy to barrel / final test
Schedule for Test and Assembly: Forward • D1,D7,D8: 16 harnesses/disc • D2,D3,D4,D5,D6: 24 harnesses/disc • D9: 12 harnesses/disc • Total 360 (2 end caps) • services to discs 7/10/02 on (90 days) => 10hr/harness • 3 full-time technical staff foreseen for assembly/testing of services for barrels and discs
Barrel Harness • DORIC and VDC • opto package • power tapes, redundancy system • many traces and connections
Forward Harness • forward harness consists of opto packages and optical fibres only • latest version - no plastic cover • test LI, responsivity in DC conditions
Test Fixture for Forward Plug-ins • equivalent to forward module • design will be transferred to 6 PCBs • allows testing of BER
What measurements do we need ? • VCSEL LI curves • pin diode responsivity • radiation hardness (batch acceptance) • BER scan/BER long term • thermal cycling/burn-in (during manufacture) • power tape continuity ? • power tape insulation ?
SLOG LITMUS BER testing: TTC link OPTIF
TTC link results: BER scan • vary light power into p-i-n diode • allows definition of working range • BER scans < 5 min
SCTLV SCTLV VCSEL LI Curves SLOG DMM • scan I using SCTLV • measure photocurrent in LAPD • 50% duty cycle • 5 min. setup/run time LAPD
SCTLV SCTLV PIN Responsivity DMM supply LED LAPD • measure I in pin bias line • LEDs for reproducibility • LAPD used to calibrate LEDs • 10 min. setup/run
Acceptance testing at RAL • Both harnesses: • responsivity 10 min • VCSEL L-I curve 5 min • BER scans data and TTC 30 min • Barrel harness additional: • HV insulation resistance 5 min • continuity/shorts 5 min • redundancy system 10 min Total time: barrel = 1 hr, forward = 45 min
Forward harness installation: assembly former • services assembled to former • former used to populate quadrant • after 4 quadrants, align cooling blocks
Forward harness installation: procedure • cooling pipes soldered on jig • mount services on front former 1. dummy modules 2. cooling pipes 3. power tapes 4. opto-harnesses • transfer services to disc • fix cooling blocks temporarily • connect patch panels test each quadrant whilst re-populating the former because: 1. quicker 2. next step, align and glue blocks • turn disc over and repeat
Final testing during installation • Both harnesses: • responsivity 0 min • VCSEL L-I curve 0 min • BER scans data and TTC 30 min • BER long-term 60 min • Barrel harness additional: • HV insulation resistance 0 min • continuity/shorts 5 min • redundancy system 10 min Total time: barrel = 1 hr 45 min, forward = 90 min
procedures for installation and testing are well defined • expect 3 technicians for harnesses • 1 man-hour/harness, acceptance • 2 hours / harness, test + installation Schedule is achievable but requires care in execution • first barrel will arrive April 02, timescale less critical • will allow refinement of procedures