1. Run period of summer 2012 Zoltán Fodor
Wigner Research Centre for Physics,
Hungarian Academy of Sciences

2. History of the period
The original plan was deranged because of faults of our magnets.
The original plan:
Test beam: June
Hadron beam : 27. June – 21. August
Be (Pb) beam : 22. August – 8. October
The modified one:
Started test beam at 18. June without magnet
Hadron beam until 8. October
Be (Pb) beam December and 14. January – 11. February 2014

3. Goals: PSD calibration Test measurement for USNA61
This point was not effected by the magnet faults
Test measurement for USNA61
Originally was planed together with PSD calibration, but it was not possible because of the VTX1 and VTX2 late readiness
After the VTX1 accident, we used only the VTX2 reduced field, could be analyzed after the new field calculations
Crosscheck of the p-+C total cross-section
For the total cross-section the field not really needed but would be nice to have it.
Some data was taken with the same field as p+C 120 GeV
Some data was taken with K-+C systems
High statistics for p+Pb collisions
The data taking was started later and was interrupted by the magnet fault.
After the magnet reparation it was continued

4. Magnet story(1)
The electronics on the cryogenics system was obsolete, had to be changed. The CRIO group would be busy during LS1, therefore must be done in this year.
VTX1 turned down after some operation in the preparation time:
He pump seriously damaged, have to produce a new element inside pump.
At that time the VTX2 was ready to use, but because it is similar system to avoid the serious damage they decided to do the same modification as on VTX1, must be warmed up the cryogenic part, do the modification and cool down again.
Water valve was opened at not used part /very probably from the VTX2 accident in 1998/ and this tube was not connected to anywhere and was not closed, but the water was flushed the VTX2 electronics.
==> The magnet was ready to use only at 3 of July
The S4 counter was not fixed strongly enough, moved at certain current and produced some spike in the monitor signal of the voltages drops on the coil, stopped ramp up the magnets and with fast discharge ramped down. The critical value was depend on the current in the VTX2.
After modification of the software, we were gone over this problem for 10.July, until that time we measured with only 30 GeV field. /VTX1 and VTX2/

5. Magnet story(2)
At 19.July Morning vacuum leak developed on the thermal screen in the downstairs bobbin of VTX1, the quench system forced to ramp down. At that time was known, one of the He circuit was broken.
Increasing the pumping power we anticipated the too fast warm up producing condensations and ice in the VTPC hut.
Warmed up the magnet with current in the coil
Opened the vacuum chambers of the magnets
Localized the leak,
The first cast was not successful.
Produced a new piece and welded it, checked with pressure and hit stress.
Closed the vacuum chamber
Started cool down with monitoring the He in the Vacuum
At the first ramp up we get some high, but not critical quench signal, but the second times was very smooth. After the warm up the coils had taken his position, the mechanical movement induced the signals at first ramp up.
The magnet was ready to use at 15. of July when started a long MD
Restarted data taking p+Pb 158GeV

6. New piece

7. Additional measurements
Used only VTX2 magnet we measured the p+C reaction at 120 GeV protons with the current in the VTX2 3500A.
The limitations came from the limit of the voltage drops on the injections to the magnets at 4000A
The signal of the S4 counter is dropped dramatically in the asymmetric field, with increased voltage and amplifier we could go until 3500 A.
Measured the cross sections of the p-+C at 350 GeV beam for the cross check of the 2009 data.
Using the opportunity we took some data with 350 GeV K- beam

8. p+Pb data 30 GeV field configuration Normal magnet settings
10. July – 19. July
21.September – 8. October

9. p+Pb second part
MD and SPS problems
After restart MD

10. 11
Magnet
date
Run
event
Target in
Target out
PSD calibration
158 GeV p+Pb
30 GeV field
30.06 – 02.07
15717
15795
0.80M
0.02M
158 GeV field
10.07 – 19.07
15852
16057
4.13M
0.41M
120 GeV p+C
Only VTX2
26.07 – 31.07
16063
16226
2.60M
0.27M
158 GeV h-+C
31.07 – 03.08
16229
16348
0.93M
0.35M
158 GeV K-+C
31.08 – 06.08
16349
16485
0.95M
0.19M
21.09 – 08.10
16542
17005
9.40M
Krypton VTX1
15554
15634
4.26M
Krypton GTPC
15669
15693
1.43M
Krypton LMPD
27.06 – 28.06
15637
15666
1.59M

11. Problems during data taking
At the beginning the DAQ crashed because of the PSD readout
The TOF readout has instability, the connection between the VME and FASTBUS system, could be looks like running correctly but the BOSbank missing
1 TPC motherboard has to be changed
Several low voltage power supply on TPC has trouble
The temperature control of the TPC huts updated but not working as before /less stable, higher gradient as before/
The pressure regulator on the MTPC-R gas-system is leaking
BPD1 lost signals , Oscar fixed it, there was a broken soldering on supply cart

12. Problems during data taking
At the beginning the DAQ crashed because of the PSD readout
The TOF readout has instability, the connection between the VME and FASTBUS system, could be looks like running correctly but the TOF BOSbank were missing
1 TPC motherboard has to be changed
Several low voltage power supply on TPC has trouble
The temperature control of the TPC huts updated but not working as before /less stable, higher gradient as before/
The pressure regulator on the MTPC-R gas-system is leaking
BPD2 continue the features of last year, decreasing amplitude
BPD1 lost signals , Oscar fixed it, there was a broken soldering on supply cart

15. To be improve One of the shifters must be experienced
Proposition to have 2 kind of shifters:
Shift leader and shifter
The new shifters has to take a learning shift in advance
It was decided 2 years ago!!!!!
The expert has to be careful enough switching on/of voltages /when we switched of the TPC high voltage, we realized the strip voltage was not switched on./

16. The full system must be ready for 3.Dec. evening
Preparation for Be run
Installation of the quadrupole magnets between the S1 and S2, to be ready for usage if we could improve the beam quality /Ilias/
Gas start 25.Nov to be ready for 3.Dec /Antony/
Installation of Cherenkov counters
Replacement of the BPD2
Installation of target holder, and alignment by geometers
No action on the magnet
One of the He flow control could not get the nominal current, but it would be enough for the low field, therefore decided not change it before the Be run /must be the full magnet warmed up and cool down/
The full system must be ready for 3.Dec. evening