AGS Cold Commissioning Plan

January 13, 2006RSC meeting

Haixin Huang

Hardware Status

• Cold snake is cold. The quench test has been done for 3T to leave the door open for stronger cold snake.

• Compensation quads and dipoles are added for warm snake during the shutdown.

• The testing of compensation quads and dipoles for both snakes is close to the end.

• AGS IPM HV has been restored to 40kV and tested. • AGS CNI polarimeter has been installed.

AGS Polarimeter Status•45 degree Si detectors have been added. The polarimeter will provide radial polarization information. •Electronics have been installed and tested.•A new (faster) DAQ system has been developed (Kin/Igor). •Vertical targets have been installed.•The new polarimeter application is ready to use(Kin/Seth).•DAQ documentation is also underway(Jeff).•The goal is to have the polarimeter running with 90 degree detectors in the first week, and 45 degree detectors will be added in the second week.•E880 polarimeter targets have been installed.

Lower AGS Extraction Energy (W. MacKay)

5.9% wsnk only

15% csnk+5.9% wsnk

•The strong cold snake changes the stable spin direction at the AGS extraction. AtR line involves both horizontal and vertical bending. As a result, the spin transfer efficiency is different.•We will lower the AGS extraction energy to get the efficiency back.•Increase the energy is not an option since it means crossing more weak resonances in the AGS.•A B-field scan around G=45.5 will be done first to confirm polarization level there.

Spin Transfer Efficiency (W. MacKay)

AGS Preparation•Main magnet functions have been built. It has 120 ms front porch and 1.4 sec flattop for polarization measurement. The rep rate would be 2.63s initially and reduced to a shorter one later for RHIC injection (~1.4 sec). •Optical functions to match this magnet cycle have been built.•Spin sign sequence coping with the setup is under development.•AGS user1 will be assigned to clod snake development (with longer flattop) and user 4 will be for RHIC injection. The other two will be for injection field and other energies (G=7.5, 12.5).•Orbit bump for the cold snake and warm snake are almost ready.

AGS Injection Lattice (run05) (N. Tsoupas)

AGS Injection Lattice (run06) (N. Tsoupas)

AGS Run Plan•AGS will start pp setup three weeks before RHIC run starts– Jan. 16. •First a few days will be setup without cold snake: establish beam; measure lattice functions; check injection polarization; snake bumps; polarimeter setup.•Turn on both snakes and establish beam at injection.•Ramp energy and push vertical tune to the desired tune window.•Field scan at Ggamma=44.5-46.5 to make sure 45.5 is a good spot for polarization.•Polarization development (vertical tune scan around 36+, vertical tune scan in early part of the ramp…..)•Extraction setup.•RF development to get smaller longitudinal emittance. •The goal is to reach 1.4*10^11/bunch with 65% polarization. •The main focus is to increase bunch intensity while maintain the polarization.

AGS SPINK Tracking

87% pol. survived

(Alfredo)

Toward Higher Intensity and Polarization•For higher intensity:

•Less beta wave around the machine. •Dispersion function stays same sign throughout the ring. •Set horizontal tune at 8.70.

•For higher polarization: •push vertical tune higher at 36+ to avoid high order snake resonance.•Keep vertical tune high during the measuring period.•Push tune higher in the early part of the ramp. •Set vertical chromaticity close to zero to reduce vertical tune spread. •Maintain emittance in the Booster and AGS.

AGS Injection Lattice (run05 CSNK only)

(N. Tsoupas)