Trickle Injection Overview Background Injection is necessary to refill beam “buckets” which have lost charge. A particular bucket is targeted for each injection shot. MCC operators limit the maximum trickle rate – typically 20Hz total. The machine is capable of 30Hz injection. The amount of charge in an injected bunch, the “quanta”, is selectable per injection shot. The “BIC” is capable of requesting any of 4 quanta, but typically only 2 are setup for use (one 20% the charge of the other). Trickle is done with the smaller quanta. Different quanta require different tuning in the injection line. M. WeaverMDI Meeting Feb 23, 2007

Monitoring BaBar is signalled before each injection shot to allow monitoring. Injection quality is monitored in two ways: SVT exposure per injection shot Triggers generated by each injection shot Triggers dropped (“deadtime”) M. WeaverMDI Meeting Feb 23, 2007

PulseNoise+BGPulseNoise+BG SVTRAD Injection Monitoring Logic 1.Receive Injection Pulse Signal 2.Integrate Pulse 3.Integrate Noise + Stable Beam BackGround 4.Dose = Pulse – (Noise + BG) 5.EPICS Variables: Max Dose : Avg Dose : # Injection Pulses (Max Dose Over 2 Seconds, Average Dose Over 2 Seconds) HER/LER Injection Pulse Signal from PEP End Injection Pulse / Begin Noise + BG End Noise + BG Time  Rad Variable Width Pulse/Noise+BG Windows (Limited by Injection Rate) S. Curry 4

SVT:FE:BG:MID_AVGINJDOSEPEP SVT:FE:BG:MID_MAXINJDOSE (FE:FW / TOP:MID:BTM) EPICS Variables: Max Dose and Avg Dose every 2 seconds S. Curry 15

LER Injection Monitoring Summary Yellow – Max Inj Dose above 1 mRad Red – Max Inj Dose above 5 mRad Black – Max Inj Dose above 50 mRad (SVT Configuration Losses) S. Curry 13

Injection- & trickle- background history Monitor by integrating SVTRAD diode signals over 12 ms after each injection SVT electronics are sometimes “upset” by exposures greater than 50 mrad / injection. HER injection-quality monitor LER LER injection-quality monitor Average Dose/Injection (mrad) M. WeaverMDI Meeting Feb 23, 2007

Most often see backgrounds extending out this side Triggers Generated Per Injection Shot

HER Trickle Quality “1M” Triggers / HER Injection typically large dose data quality (Hint of ~360 Hz structure) May 31, 2006 Stored beam background level Large long-time component Longitudinal Frequency (energy ↔ time) May 31, 2006 M. WeaverMDI Meeting Feb 23, 2007

Monitor using triggers gated around the passing of the injected bunch (1  s x 15 ms) Injection contaminates the BaBar physics data sample if backgrounds endure too long HER injection-quality monitor LER LER injection-quality monitor Injection- & trickle- background history Triggers/Injection M. WeaverMDI Meeting Feb 23, 2007

Deadtime associated with HER injection JAS Plots L1 inhibit windows chosen to maximize livetime. Optimal when deadtime ~ 12% at end of inhibit window (3.75ms) All recorded triggers Shows L1 inhibit window and “sampling” triggers. Verifies that L1 hardware is working. M. WeaverMDI Meeting Feb 23, 2007

Some numbers: Hardware filter window (maintain DAQ livetime) 0.54 ms / inj = 0.054% * r (Hz) Physics filter window (maintain DQ) 2.79 ms / inj = 0.28% * r (Hz) HER ms / inj = 0.19% * r (Hz) LER Calibration filter window 30 ms / inj = 3.0% * r (Hz) Injection rates are typically 5-10 Hz. Occasional periods of 15 Hz PEP needed 20 Hz LER to explore 10**34 lumi Machine is capable of injecting at 30 Hz Administrative limit is 20 Hz M. WeaverMDI Meeting Feb 23, 2007