E01-017(g6c) Running Condition
ASYNC TRG
The photon range of interest for E01-017 is for photon energy greater than 4.8 GeV. We will thus keep only the first 12 T-counters (up to 0.84xE_beam) of the tagger into the MOR. All others will be disconnected from the MOR (and need to be terminated with 50 Ohms). We will nevertheless keep HV on all T's, to have them in the scalers (and read all E/T in the DAQ). (tagging range: 0.84 to 0.95 of E. Running a 5.734 GeV electron beam will produce a photon beam in the energy range [4.8, 5.45] GeV. No prescale will be used.
Two ASYNC will be set:
ASYNC 1 ------> MOR(1-12)*ST(2/3) initial values MOR 200MeV (thr.) 10ns (width) ST 200MeV (thr.) 15ns (width)
ASYNC 2 ------> MOR(1-12)*ST(1/3)
they differ only on the ST coinc.The production trigger will be determined on commissioning. Initial delays: MOR (2ns) and ST(14ns) from last run.g6c production trigger (at high current) two_sectors_async(1or2) -> bit 1 , no prescale. There are two files from last g6b run
g6_TWOSECTOR_ASYNC2
g6_TWOSECTOR_60_ASYNC2
both make coincidence with async2. the sencond uses only TOF paddles in the 60 degree forward direction (without 6 last TOF counters) there are also g6_open (unbias)2x10^-4 or 3x10^-4
10^-5
1/2 B_max
I_torus= 1688 A
2.8 mm
WE WILL STRIVE FOR THE MAX PHOTON FLUX
The desired photon flux is of 1.5-2.0x10^7 ph/sec in the tagging range [0.85,0.95]*5.734 GeV. This requires a 60nA electron beam flux. We will run at the max DAQ rate (4000Hz) and dead times of about 80%Level 2: Need to load right configuration. We are requiring any two sectors. We will need to have a Level 2 that provide "one DC track" in any of two (or some other combination: talk to Dave or Elliot)
Same as g8 procedureBernhard Mecking's notes
LH2 target, 18x3 cm cylindrical cell (same as g8), pulled back upstram by 100cm from the center of CLAS.