APEX Report April 28-29, 2009 May 4, 2009

1. APEX ReportApril 28-29, 2009May 4, 2009 Fulvia Pilat Time Meeting, May 12 2009

2. APEX Schedule April 28-29 2009 Injection Injection BBQ 106turn BPM AC dipole Ramps BBQ Injection Store BBQ 09-26 DA measurement with AC dipole Bai Pilat 08-29, 08-10 Polarimeter study Huang, Zelenski +team 09-05 D0-DX study MacKay Satogata 08-08 Long Range beam-beam Fischer +team 07-19, 07-20 Noise from Main PS Schultheiss Minty 7pm 9pm 11:30pm 2am 5am 7am

3. APEX Schedule May 4th 2009 Injection Ramps BBQ 07-19, 07-20 Noise from Main PS Schultheiss Wilinsky 09-05 D0-DX study MacKay Satogata 9am noon 3pm 4pm

4. RHIC/AGS Polarimeter Study Huang, Zelenski+team • Fixed target polarization for two intensities (1.4 and 1.6*1011) with 12 bunches in both rings with two polarimeters. AGS measurements were done with similar intensity. • Polarization profile measurements were done with both rings and both planes with 56 bunches. AGS horizontal and vertical profiles were taken the same time. • Sweep and fixed target measurements were done with 56 bunches for comparison. • Note: Keith tuned emittance down for AGS before the study, we did not see much change on AGS IPM or CNI target scan, but the polarization profiles measured in AGS is flatter than before.

5. Polarization Profiles of RHIC and AGS Ring Horizontal P0 sigma Vertical P0 sigma AGS 60.453+-3.341 3.981+-1.909 60.979+-2.374 3.994+-1.491 Blue 55.915+-2.623 3.462+-1.258 60.089+-1.860 4.804+-2.294 Blue 64.523+-1.631 3.386+-0.427 Yellow 58.923+-1.162 3.732+-0.500 57.904+-1.661 3.482+-0.447 • The profiles are consistent between AGS and RHIC with the statistics. • The  actually is P / I. These numbers from last year at 100GeV are averaged 2.5, this year is about 3(average of many fills). Given the large error bars, I can’t say there is profiles developed in RHIC ramp.

6. PS beam noise - summary Schultheiss, Minty • Four ramps were executed with different configurations of the electrostatic shield and a capacitor across the grounding resistors.

7. Ramp 1 Results

8. Conclusions • Floating the Electrostatic Shields in the Dipole Ramp PM reduced the noise during the ramp. Yellow showed more reduction than Blue. • The Capacitor had a less dramatic reduction in the noise. • The present configuration is with the shields floating and no capacitor.

9. Plan for the experiment Use pattern BBLR_34x34 (28x28 + 6 non-colliding bunches), 2e11/bunch, accelerate and collide, will not ramp up the RF voltage CNI emittance measurement=> emittances measured around 35 (Blue) and 22 (Yellow) mm.mrad : BBQ was left one during the ramp 5A, position scan in Blue and Yellow, orbit and BTF measurements Retract, CNI emittance measurement => around 50 (Blue) and 22 (Yellow) mm.mrad 50A, position scan in Blue and Yellow, orbit and BTF measurements Retract, CNI emittance measurement Time permitting, change chromaticity, repeat one scan Fischer Robert-Demolaize Calaga

11. Conclusion Plan executed: distance scans with both 5A and 50A scans in both beams, including head-on beam-beam. Suffered from larger than usual emittance (about 30 mm.mrad); BBQ should be off next time. Additional beam time to study in details the behavior of non-colliding bunches + chromaticity changes ?

12. MacKay, Satogata

15. APEX Schedule May 12-13 2009 Injection High intensity Injection High intensity Gamma-T No snakes Injection Injection Store BBQ 09-17 Space charge and Beam-beam Fedotov + team 09-21 Bunch length limit Ptitsyn+ team 09-06 Off-momentum beta-beat Calaga Glenn 08-08 Long Range beam-beam Fischer Demolaize +team 09-07 Impedance Calaga 7pm 10pm 1am 3am 5am 7am