NuMI –Sep 2 - 8 ’05

1. NuMI –Sep 2 - 8 ’05 • Continued running with He backpressure containing Target water leak • Plan a target scan today • Spare target ready in ~ 2 weeks • Evaluate next week for going to 6 batches in NuMI only • Smooth operation, very few NuMI system downtimes • 4.23E19 POT • Running at 5 batches, mostly 11 turns, 2.05-2.25E13 ppp • ~ 32 beam permit trips during operation [25 were from MI-RF] • MI/RF studies for more robust performance during bunch rotation can benefit NuMI considerably • Peter Lucas will be NuMI Coordinator from Sep.9 to Oct.3.

2. Weekly Integrated POT 2nd best week – 4.23E18 POT Total protons 5.2E19

3. NuMI Beam Permit System • The combination of very intense NuMI beam, plus constraints on beam cleanliness to preclude ground water irradiation lead to use of a comprehensive beam permit system • 3-5 off normal pulses [<10 seconds] can destroy a magnet vacuum chamber • Wayward beam can also damage target cooling / horns • Baffle protection exists, but not failsafe • Radiation monitor (Hobbit door scarecrow) trips beam at DC fractional loss of few x10-5 of beam; plus ES&H administrative limits for allowable accidental beam loss – trip here at several x10-4 fractional loss. • NuMI beam permit system includes ~ 250 inputs. Included is monitoring of power supply status, limits, MI beam quality before extraction, NuMI beam loss, targeting position, status for target, horn, absorber. • How well does all of this work??

4. NuMI BPS Daily Trips since Aug.01from ALL causes Typically ~ 28k beam pulses/day

5. BPS Trip Duration (sec)Aug.01 – Sep. 07Data Logger computerized search Significant part of overflow is trips during no beam periods Preliminary! Still addressing the exceptions Time between $23 pulses after BPS trip D. Jensen

6. NuMI Weekly Beam Permit System Trips since Aug 1:~ 200k pulses/wk(from MCR & NuMI e-Logs)

7. Impact of BPS trips on timeline(fraction of downtime) • If we simply take ALL trips x <ave. trip duration >, have a time loss of ~ 6 hr 30 min since Aug.01. • For 140 hr operation/week, would be 0.8% loss • Significantly less still for the most recent month • Clearly there is some impact of the NuMI permit system on Pbar operation, as there is for use of the Pbar permit system on NuMI operation. But these are relatively quite small. • NuMI generates more trips, due to having BLM’s in the permit system • But significant NuMI downtimes have also been generated from Pbar permit control • From previous chart of trip causes – if include everything BUT Pbar induced as due to NuMI, then a differential beam loss time would be: • 410 – 98 = 312 NuMI trips x <46 sec> = 4 hrs since Aug .01 • In context, there was also 10 hrs of lost beam (NuMI & Pbar) on Aug. 16 from not having BLM”s in Pbar permit

8. A total of 11 NuMI Rad detector (Scarecrow) trips have occurred since Aug.01 8 from MI RF 3 from Slip Stacking/Booster Operating conditions have been changed to permit Ops turn on afterward except for large beam loss (>5 loss monitors tripped). NuMI Rad Monitor Trips We have had 4 very large beam loss pulses in NuMI line since early June. Two occurred night of Sep 1-2, with 1E13 lost each time – MI RF problems Refinement of BPS inputs continues to abort these prior to extraction