User name LeRose
Log entry time 10:33:18 on June12,2002
Entry number 85936
keyword=Right Dipole Tests
In response to problems encountered in the night I tested the controls on the right dipole. The plot shows the current in the magnet (black), the field in the magnet (blue), and the lead voltages.
I started by typing P0=3.0 GeV/c. The magnet ramped up correctly and started to regulate. This is the 1st plateau in the blue curve.
Next I typed P0=3.1 GeV/c. Again the magnet ramped up, this time limited by the software current limit of 1140 amps. The maximum of the black curve. Here I only waited long enough to see the regulation start to work, see the little dip in the black curve after it 1st reaches the maximum.
Then I typed in P0=5.0 GeV/c. The controls software, as it is supposed, to refused this input and returned the correct maximum P0 set of 3.16 GeV/c. The power supply was again set to the maximum (1140 amps, really Iset=1140 amps but the achieved current is about 1144 amps, well below the hardware limit of 1200 amps). When the magnetic field reached the correct value for P0=3.16 GeV/c the regulation started again and the field was stablized.
During the test I also monitored the He level in the magnet, the lead flows, and the coil
Everything worked exactly as it was supposed to. It is very unlikely that whatever problems were encountered last night had anything to do with the controls.
Ed Folts and Co. are investigating other possibilities.
Presently ramping down to zero so they can jumper out the UPS that keeps blowing fuses.