APEX Report April 28-29, 2009 May 4, 2009
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Transcript of APEX Report April 28-29, 2009 May 4, 2009
APEX Report
April 28-29, 2009May 4, 2009
Fulvia Pilat
Time Meeting, May 12 2009
APEX Schedule April 28-29 2009
5am9pm7pm 11:30pm
Injection
08-29, 08-10Polarimeter studyHuang, Zelenski+team
2am
RampsBBQ
09-26DA measurementwith AC dipoleBaiPilat
7am
InjectionBBQ106turn BPMAC dipole
07-19, 07-20Noise fromMain PSSchultheissMinty
09-05D0-DX studyMacKaySatogata
08-08Long Rangebeam-beamFischer+team
StoreBBQ
Injection
APEX Schedule May 4th 2009
9am noon
Injection
3pm
RampsBBQ
4pm
07-19, 07-20Noise fromMain PSSchultheissWilinsky
09-05D0-DX studyMacKaySatogata
RHIC/AGS Polarimeter Study
• 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.
Huang, Zelenski+team
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.
PS beam noise - summary
Four ramps were executed with different configurations of the electrostatic shield and a capacitor across the grounding resistors.
Ramp Number
Blue Dipole Ramp Electrostatic Shield
Yellow Dipole Ramp Electrostatic Shield
Capacitor in Yellow Dipole Ramp OCC
1 Floating Switched In and Out Not Installed 2 Floating Grounded Installed for
Entire Ramp 3 Grounded Grounded Switched In and Out 4 Floating Floating Not Installed
Schultheiss, Minty
Ramp 1 Results
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.
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
FischerRobert-DemolaizeCalaga
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 ?
MacKay, Satogata
APEX Schedule May 12-13 2009
5am10pm7pm 1am
InjectionHigh intensity
3am
09-17Space charge andBeam-beam
Fedotov + team
7am
09-06Off-momentumbeta-beat
CalagaGlenn
08-08Long Rangebeam-beam
FischerDemolaize+team
StoreBBQ
InjectionInjectionInjectionHigh intensityGamma-TNo snakes
09-21Bunch lengthlimit
Ptitsyn+ team
09-07Impedance
Calaga