Lumi run: 16 mA e+, 99 mA p.
CJC1 and 2 at full HV.
H1 lumi photon spot at y = +1.7 cm.
Lower with vertical asymmetric lumi bump 56-27-27-56:
Watch BTS6.2 rate:
The CJC currents did not change during this excercise!
TDC spectra: 96 ns window, 1 ns binning.
Triggered by H1 ep data, look for random coincidence in BTS:
At base rate, from p and e background:
Clean spectra, showing p and e peaks 40 ns apart, as expected at 6 m.
At 300 kHz in BTS6.2:
The BTS6.2 counter develops a tail behind the e peak.
The late peak is 4-5 ns after the e peak.
If it is due to backscattered synchrotron radiation, the scatter
happens about 70 cm right of BTS6.2, which is inside the GI2 magnet.
At 2 MHz in BTS6.2:
Repeat the same with the shorter asymmetric vertical bump 27-2-2-27:
The TDC spectrum at 2 MHz shows the same 3rd peak:
Study horizontal effect:
1. photon spot lowered to 0.4 cm => 350 kHz.
2. move photon spot horizontally inwards to +0.6cm => 1.3 MHz!
3. move photon spot horizontally outwards to -1cm => 120 kHz.
