1 / 8

Thursday 15.7

Thursday 15.7. 04:20 Stable beams 13_8_8_8 Peak luminosity around 1.2E30 cm-2s-1. Dampers on. Intensity and luminosity lifetimes not as good as previous fill. 06:00 TOTEM RPs at 25 sigma vertical plane, 30 sigma hor. plane. Problems with the TOTEM RP FESA server…

jaunie
Download Presentation

Thursday 15.7

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Thursday 15.7 • 04:20 Stable beams 13_8_8_8 • Peak luminosity around 1.2E30 cm-2s-1. • Dampers on. • Intensity and luminosity lifetimes not as good as previous fill. • 06:00 TOTEM RPs at 25 sigma vertical plane, 30 sigma hor. plane. • Problems with the TOTEM RP FESA server… • 12:00 Damper off, lifetime of beam2 increases by a factor 2-3. Beam2 damper settings not yet fully optimized. • 13:00 Dump beam. • 15:30 Injection – Hump hunting. • Test effects of the GSM. No effect seen on the hump. 8:30 meeting

  2. Lifetime damper ON - OFF 8:30 meeting

  3. Hump vs. GSM signal in the tunnel • Circulating beam (single nominal bunch) available at ~16:25 Started to switch OFF GSM network in the tunnel in the following order: • Sector 12 + TI2 Sector 23 Sector 34 sector 45 Sector 56 Sector 67 Sector 78 Sector 81 + TI8 + UX15 • By 17:24 all GSM transmitters in the tunnel were OFF No significant modification on the hump amplitudeBy 18:00 the GSM network was re-established (for a total interruption of 1.5 h) This test was possible thanks to the contribution of IT/CS (A. Pascal, F. Chapron). G. Arduini et al.

  4. Hump vs. GSM signal in the tunnel • No significant change in amplitude • Typical slow drift in frequency as observed in other occasions. GSM OFF – B2H GSM ON – B2H GSM ON – B2V GSM OFF – B2V

  5. Thursday 15.7 • 18:00 : Prepare for 13 + ½ nominal bunch configuration (LHCf) • LBDS beam position interlocks reconfigured. • Damper noise improvements for beam2. • 20:00 Quench heater of MB in sector 45 discharging. To be fixed before the week-end. • 22:00 CMS reporting overpressure problem in their cavern. • 23:00 Access for CMS • LBDS beam position interlocks reverted to initial situation. Give up on 13 + ½ bunch scheme. • QPS reset on S67. Not pre-cycled. 8:30 meeting

  6. Friday 16.7 • 00:30 Injection • Beams dumped twice by FMCM on RQ5.LR3. M. Zerlauth confirmed that the problem seems to be internal to the FMCM + voltage divider system. • Beam losses at injection, suspected scraping in the SPS, RF loops, energy offsets… • Abnormal bunch length increase in the LHC. Injection losses due to un-bunched beam in the LHC. Large synchro loop errors. • 04:00 RF work at injection. • One explanation : the field in the LHC is off by around 0.3%, but not seen on the trajectories. Still investigating… • SPS : vacuum leak developing in sextant 4 since yesterday evening. 8:30 meeting

  7. Bunch length and losses 8:30 meeting

  8. Friday 16.7 • Restore injection. • Multi-bunch injection. • Access for quench heater PS in S45. • Over the week-end: • Physics • Possibly short loss map measurements at injection. 8:30 meeting

More Related