Check TPC High Voltage for dE/dx

The function TCHKHV, from the ALEPHLIB, is used to check the TPC high voltage before using the dE/dx information from the TPC. It checks the data base bank TDBS to find whether any sectors were being intentionally operated at reduced voltage during the run in question. If so, then only the normal TPC HV bit is checked. Otherwise, the ``dE/dx'' HV bit is checked.

Input arguments:

KRUN

ALEPH run number.

KEVT

ALEPH event number.

Output arguments:

IFLG

What kind of test was made?

• =0: test was made on dE/dx HV bit.
• =1: test was made on TPC tracking HV bit.
• =2: no test was made (banks not found). TCHKHV=.FALSE.
TCHKHV
= .TRUE. if HV is on; .FALSE. otherwise.