The programme – as presented yesterday

1. The programme – as presented yesterday LHC 8:30 meeting

2. Programme last evening LHC 8:30 meeting

3. Programme this morning LHC 8:30 meeting

4. Thursday 14th February • 07:24 Last dump from Stable Beams for a long time… • Operator dump! • 08:30 At injection, start of DS Quench Tests. • 13:19 Dump ramp 1 of collimation quench test at dispersion suppressor, slow losses, • 3 bunches for ADT tests, with asynchdump • Asynch dump OK • 15:09 Dump ramp 2 of collimation quench test due to interlock from collimators when moving to relaxed settings • Several source, open TCDQ energy threshold • Access for installing scope Q6 quench test at injection • Took down the sector, not foreseen by some • Pre-cycle etc. • 20:21 Dump ramp 3 of DS quench test, 144 bunches, about 500 kW losses, dumped by BLMs without quench • Increase BLM limits LHC 8:30 meeting

5. First ‘real’ DS test ramp with 144 bunches Blue - excitation strength Green - intensity Red - excitation running The beam was dumped 3 seconds before the excitation strength started to increase to provide constant loss rate. LHC 8:30 meeting

6. By the collimation team: • In more detail • dumped on the RS10 for the BLMQI.09L7.B2I10_MQ; for this magnet the MF was still at 0.1. • We achieved a peak loss rate of 8-8.5e11p/s over about 2 s (exceeding what was achieved in 2011). • Other faster RS's achieved up to 85% of dump levels (TCPs, TCLAs). • We achieved (without quenching) losses up to 1.5 times larger than the assumed quench limit (first time for proton losses). • We decided to proceed as it follows: • Increase MF on a selection of DS magnets to 0.5. • Change the master thresholds by a factor 2.5 for the collimators that are close to dump limit for fast RS. • In the meantime, deploy the firmware change for the ADT to allow excitation on 2 trains. LHC 8:30 meeting

7. Continue DS quench test 00:07 Dump again on BLMs (no quench) LHC 8:30 meeting

8. Summary of second attempt to quench. • Achieved peak loss rates of 640 kW, corresponding to up to 1e12p/s. • Dumped on RS10 on the BLMQI.08L7.B2I10_MQ. We reached 3 times the quench limit in RS10, without quenching. • This monitor has MF=1 so we can go above that levels only by changing the MT. • Next attempt: • Increase the intensity by a factor ~1.5 (144+72b) • changing the limiting Q8 monitor by a factor 2.5 by changing the MT (in RS09 and above). • Other changes MF's in the DS, listed LHC 8:30 meeting

9. DS quench test with B2 (144+72 bunches) • Dump at 3:15 • We achieved peak losses up to 1MW without quenching. Peak loss rate: about 1.65e12p/s • This time we dumped on a TCLA collimators (thresholds were at the electronics maximum) • RS08 • The Q8 reached for RS09 a factor 3.4 above the assumed quench limit. • The primary collimators experienced a temperature increase up to 10 deg. LHC 8:30 meeting

10. Quench test at injection Q6.L8 • 05:46 It did quench • As we know we can with injecting beam • TCLIB closed • Some iteration on current and injected intensity • Quenched on • RQ6.L8 at 2500 A • One shot at 6.54E10 • However, not sure if it really quenches or just triggered the QPS • “RQ6.L8 trip analysis...it looks a bit quick to be a quench” • Presently • Access for scope installation ADT fast losses quench test • Access for IPQ threshold adjustment LHC 8:30 meeting

11. The Plan LHC 8:30 meeting