• Goals of the Workshop
• Future requirements of the damping rings
• Recent performance of the rings

• Divided into five sessions
• Reliability and Engineering Issues (M.Munro)
• Operational Aspects (D. Schultz)
• Accelerator Physics and Beam Dynamics Issues (P. Krejcik)
• RF Systems (J. Frisch)
• Diagnostics (M. Ross)
• Transparencies + abstract collected for a Workshop Proceedings
• Session chairman should make a one page summary.

Workshop Goals ...

• State the future requirements of the Damping Rings
• In each session we will try and address:
• what needs to be preserved
• what changes need to be made in the way we run things
• what upgrades are necessary
• what new enhancements and avenues can we explore

• Routine PEP II injection (J. Seeman 2/11/98)
• Use of stable, low emittance SLAC linac beams at currents which are low with respect to typical SLC operations
• 0%-l00% fills in 6+3 minutes with 60 Hz interlaced operation
• Injected Current at Septum (1 €10¹⁰ e+- per PULSE)
• Normal Filling Time (includes 3 min for detector state changes)
• Topping off (80-100%) (min) 6
• Filling time (0-100%) 9
• Linac Repetition Rate (pps) 120 (sector 0-10) & 60 (sector 1 1 - 1 9)
• Intensity (at HER/LER Septum) 1*10¹⁰ ppb.
• TIME TO FILL
• Need 5 Linac bunches per bucket for top-off
• 1746 -5% = 1658buckets per ring
• 60 Hz per ring
• 2 rings per PEP-11 THUS 5xl658'x2
• Time to fill = 5x1658x2/2x60Hz = 2.3 minutes
• Add 3 minutes to make ring adjustments and call it:
• 6 minutes to top off and 9 minutes to fill empty rings
• Injected Vertical Emittance
• HER (m-rad) l0xl0-5
• LER I.5x10-5
• Injected Horizontal Emittance
• HER l0xl0-5
• LER 5xl0-5
• Invariant Beam Emittance (Ex/Ey)
• HER (m.rad) 85/3.3 x10-5
• LER 39/1.6 x10-5
• Injection Reliability Improvements (JTS)
• Run linac at reduced rate (60 or 30) to save power and last longer?
• Why not run the damping rings at a reduced energy? (Say, 900 MeV) Easier on the kickers [less voltage and radiation], only need one RF cavity, reduced voltage in that cavity, We would have one spare RF station in Sector 1. Makes pulsed PBH for ESA easier. Lower emittance too! maintain capability (for now) to inject 2 bunches per pulse (may make 30 Hz acceptable)

Future Performance Requirements ...

• Possible future SLC operation
• End Station A experiments with with similar requirements to SLC
• Interlaced operation of End Station A and PEP II injection
• Test bed for damping rings in future Linear Colliders

• Intensities, Emittances, Reliability
• e^- 4-4.2€10¹⁰ ppb extracted from the ring
• e⁺ 3.4-4€10¹⁰ ppb
• throughput an issue

• e^- e_{x ~ 3.2-3.6 10^-5} e_{y ~ 0.3-0.5 10^-5}
• _e⁺ e_{x ~ 3.7-4.5 10^-5} e_{y ~ 0.15-0.3 10^-5}

• Improvements in RTL emittances. Cumulative benefits of:
• septum alignment
• RTL quadrupole multipoles
• RTL optics with larger R₅₆ (lower V_comp, lower DE)
• SRTL bellows sleeving
• RF Cavities
• pump HOMs shielded
• window failures (Cavity 590 only)
• klystron magnet failures
• Kickers
• still waiting for LIC style ceramic chambers
• kicker magnet radiation dose
• vacuum chamber alignment