1. A.Kulikov SLAC MAC review October 2003
Electron Cloud Issues
A.Kulikov
SLAC
MAC review October 2003

2. Electron multipacting in the LER straight sections.
Feb A
Feb A
Current, mA
Current, mA
Oct A
Oct A
Current, mA
Current, mA

3. Electrons in the HER. All HER holding vac. pumps
HER distributed ion pumps

4. Electrons in the LER arcs
VP _29_03
Elec
VP4031 (6-8)-Jul-01
Solenoid OFF
VP Aug-01
Solenoid ON 14-Aug-01

6. Electron multipacting and luminosity
July 2000
29 sections ON
2-May-2000
Before 17:00: 10 sections of solenoids ON (Str. 12)
After 18:15: 23 sections ON (Str. 12, Str. 4, Str. 8)
The last section in the straights was energized 16-Mar-01 (54 total)
Solenoids in the LER arcs: the first - 23-Apr-01, the last - 9-Feb-02

7. Positron beam sizes driven by the electron cloud effect
31-Jul-2000

8. Str. 12 solenoids effect on the beam sizes
Str.12 solenoids effect on the beam sizes. All other solenoids in the ring are ON, single ring.
Lifetime
Horizontal beam size
Vertical beam size ON
OFF
1.46 A
450 mA
28-Aug-01

9. Solenoids Arc-3 effect on the beam sizes
Solenoids Arc-3 effect on the beam sizes. All other solenoids are ON, single beam.
Lifetime
Horizontal beam size
Vertical beam size
1.5 A ON
OFF
0.5 A
28-Aug-01

10. Solenoid field scan (Bmax = 30Gauss) 4” round SS chamber, colliding beams Bunch pattern - by 3 LER current - ( ) A Number of bunches

11. Summer 2003 improvements:
Additional 50 Gauss solenoids for all straight sections
drift chambers.
Double the field at pumping T-s, transitions and small
drift chambers for all LER straight sections.
Additional solenoids for “no sexstupole” girders in
all LER arcs.

12. 50 Gauss solenoid section

13. Pumping T

14. Double the field at the pumping T-s

15. “No sextupole” chamber