1 LBDS Testing Before Operation Jan Uythoven (AB/BT) Based on the work of many people in the KSL, EC and TL sections

Jan Uythoven, AB /BT LBDS Audit, 28 January Outline MKD and MKB Systems Testing before installation Calibration in the laboratory Testing in the machine Calibration Reliability run Testing of the complete LBDS System From local operation to running the complete system from the CCC Conclusions

Jan Uythoven, AB /BT LBDS Audit, 28 January Calibration in the Laboratory before Installation MKD: 2 x 15 Magnets 2 x 15 Generators + 2 x 2 Spares MKBH: 2 x 6 2 MKBV: 2 x metal coated ceramic chambers: partly calibrated! Inductive field probe !

Jan Uythoven, AB /BT LBDS Audit, 28 January Why Calibration? MKD and MKB Systems Calibration of individual components Test all magnets with the same reference generator Test all the generators with the same reference magnet Test some of the ceramic chambers (different resistance of the coating) on the same magnet and the same generator Determine the relation between measured field and current Precise measurements of the magnet and generator performance gives: Quality assurance Find the “bad” magnets / generators and fix them, measure again and see if its better  Weak components were detected and replaced during the calibration process Critical parameters determined Method for the analysis of current waveforms developed  Later used by IPOC and XPOC Comparison with specification / design  Just ok on rise time and overshoot For MKD determination of individual trigger voltages as function of ‘beam energy’  Necessity ‘discovered’ during the calibration process Used for sorting and assigning equipment positions in the LHC

Jan Uythoven, AB /BT LBDS Audit, 28 January Results: Some MKD Calibration Results

Jan Uythoven, AB /BT LBDS Audit, 28 January MKBH Calibration Results

Jan Uythoven, AB /BT LBDS Audit, 28 January Measurements once installed in Tunnel Repeat same calibration measurements in tunnel Comparison of Reference Measurements Example for measured Pulse Length Typical MKD generator Pulse length comparison calibration hall and two measurements in tunnel Measurement of pulse which is too short and continues to become shorter: Compensation capacitor replaced

Jan Uythoven, AB /BT LBDS Audit, 28 January Results XPOC over Several Weeks of Running (25/11/07 to 12/01/08) 15 MKD systems, beam 1, at 2 TeV Downwards trend on Amplitude not understood Pearson transformer Hysteresis Comm. of Rogowski trans. Capacitors Temperature effects Pulse length: replaced capacitors 100 % point, relative [%] End point, after 91  s [%] Overshoot 2 [%] OverShoot 1 [%] Compensation capacitor replaced

Jan Uythoven, AB /BT LBDS Audit, 28 January Reliability Run A testing policy can be applied to 2x15 MKD generator branches per LBDS, 60 in total, in order to accept or reject the hypothesis that they are SIL3 at least. The test considers the branch failures only and not the system failure. A test of three months with 1 hour missions ensures that the system is SIL3 or better at 95% confidence level if less than 6 generator branch failures are observed. MKD SIL3 Decision threshold Failures for a 3 months test is the assumed failure rate of one generator branch in order that MKD system is SIL3 Failure rate Observed failures Started running in November So far no failures detected !

Jan Uythoven, AB /BT LBDS Audit, 28 January Energies Used during Reliability Run Philosophy is 12 hours stable at 7 TeV settings followed by one pulse, and series of 5 pulses at different energies (average ~ 1/hour). Always following realistic ramp rates.

Jan Uythoven, AB /BT LBDS Audit, 28 January System Commissioning Connect up to non MKD – MKB equipment. Add equipment when they become available Timing – Beam Interlock System (BIS) To be done in the coming weeks, as LBDS – BIS is a safety critical link Close BIS loop locally in point 6 MSD: ramp synchronously with MKD/MKB TCDQ: position to follow ramp Beam Instrumentation (XPOC) RF (synchronisation) Q4 – possibly run in short circuit when magnet not cold Main dipoles for BEM: connect when cold and available Once connected up to the BIS, running from the LHC Control Room Test as much of the equipment as possible Operator experience with the LBDS equipment First tests to start in two weeks

Jan Uythoven, AB /BT LBDS Audit, 28 January Conclusions For the MKD and MKB systems standard, precise measurements have been made before installation and, once installed, during ’continuous’ pulsing They have been successfully used to detect weak components during initial testing and also for one generator once installed They will also be used for the IPOC and XPOC analysis Today, the systems have been pulsing for several weeks as part of the reliability run No failures detected so far. Would expect about two failures on the switches, according to dependability model. Some trends are observed which are not yet fully understood No risk to safety, as trends are slow and captured by the pulse analysis Reliability run ongoing for the coming months, in parallel with other works System commissioning starting in two weeks