1. Francesco Gonnella NA62 Collaboration meeting Washington DC, U.S.A.
KTAG status report
Francesco Gonnella
NA62 Collaboration meeting Washington DC, U.S.A.
29 August 2017

2. Hardware developments
Second WIENER crate installed to ease TEL62 maintenance
3 TEL splitters per crate
The boards can now safely be removed from the crate
Modification for H2 operation:
N2 flushing for CEDAR diaphragm motor installed
Intrinsic safety barrier protecting CEDAR diaphragm limit switches installed
H2 safety testing
Mock H2 filling/emptying performed
New flame retardant shroud installed
ADCs monitor Wiener crate 2 voltages
No under voltage was observed during ktag 4 tel62 reset
Francesco Gonnella - University of Birmingham
29 August 2017

3. TEL62 firmware reload Board reloads
Many board reloads of KTAG TELs in 2017
A metal shield put in front of crate
The number of reloads did not change significantly
Francesco Gonnella - University of Birmingham
29 August 2017

4. Hardware status High voltage
Some PMTs voltage above threshold (~905 V)
Affected boards are not always the same
The first 8 channels of the board are involved
Power-cycling the HV crate always solves the problem
Saleve-side low voltage PSU Ethernet port broken
No longer remotely controllable
Broken y-position sensor
CERN experts replaced it
Dead and noisy channels are reported on the right
2 noisy channels
4 dead channels
Francesco Gonnella - University of Birmingham
29 August 2017

5. Radiation at the KTAG station
A straw radiation monitoring was installed in KTAG area
Cosmic rate (CR) is 0.4 Hz per straw
At KTAG station, rate with no beam is ~3Hz (6 times CR)
During interspill the rate goes up to ~20 Hz (50 times CR)
Position
Value (with 18E11 on T10)
Interspill
Lower KTAG Crate
~45 kHz
~0.38 kHz
Upper KTAG Crate
Upstream concrete
~70 kHz
KTAG box
~430 kHz
~50 KHz
Francesco Gonnella - University of Birmingham
29 August 2017

6. Pressure scan 2017 Run number 7391 Beam Intensity on T10 = 17.6E11
Diaphragm = 1.5 mm
Pressure scan from 1.8 bar to 1.7 bar (around kaon peak)
Francesco Gonnella - University of Birmingham
29 August 2017

7. Pressure scan 2015 Run number 3143
Full Pressure scan from 1.6 bar to 2 bar
Diaphragm = 1.5 mm
peak: ~1.75 bar
Francesco Gonnella - University of Birmingham
29 August 2017

8. Pressure scan: 2015 vs 2017
Pressure value set for Kaons: bar
Kaon rate = 22.5 MHz (from computations in NA62Reco)
Better K/p separation at 1.5 mm Diaphragm
2015
2017
Francesco Gonnella - University of Birmingham
29 August 2017

9. Saleve-Jura Asymmetry
2017 spatial alignment
After Pressure scan the diaphragm aperture was reduced down to ~1.3 mm, while keeping the alignment
The final CEDAR vessel reference positions are reported in tab
X [mm]
Y [mm]
Diaphragm [mm]
Up-Down Asymmetry
Saleve-Jura Asymmetry
Number of hits
-0.232
-0.756
1.529
-0.052
-0.021
20.25
-0.233
-0.758
1.292
-0.054
-0.023
20.20
Francesco Gonnella - University of Birmingham
29 August 2017

10. KTAG efficiency MB 29 August 2017
Francesco Gonnella - University of Birmingham
29 August 2017

11. KTAG time resolution MB 29 August 2017
Francesco Gonnella - University of Birmingham
29 August 2017

12. Francesco Gonnella - University of Birmingham
TDCB errors
Stoyan
Francesco Gonnella - University of Birmingham
29 August 2017

13. Conclusions and future plans
Hardware is good
KTAG is up and running according to specs
Efficiency is bla better than 2015
Time resolution is blabla
Short-term plans for board reload
To see if thermal neutrons are causing them, a Cd foil shield can be put around crates
Radiation monitors can be used to find suitable position for crates:
On a platform few meters above their current position
At the same height but farther downstream in TCC8:
to GTK3
to LAV5
What else?
Francesco Gonnella - University of Birmingham
29 August 2017