1. Interpretation and use of BLM Data
B. Dehning
LTC, B.Dehning

2. Location of Monitors (overview)IR
TAS or
BPM Q1
TRIPLET two beam
TRIPLET abs
TAN
(1+5)
D2 (2+8)
TCL 1
TCL 2
XRP 4 locations
MSI one side
TDI one side
TCD
D one side
TCL i one side
MSD
TCD Q
TCD S Q5
Collimator
DIS MB 8 prot
DIS
MB 11 prot
DIS MB 9 ion
DIS MB 10
cap ion 1
ISU
2 * IU IU
1 * IU 2
---
2 * ISU 3
all ISU 4 5
4 * IU 6 7 8
LTC, B.Dehning

3. Location of Loss Detectors at IP8
left
right
At the listed elements up to 8 detectors
mounted on:
Cryostat
Single support
Detectors:
Ionisation chambers
Secondary emission
Detectors could be:
non mask able
mask able
LTC, B.Dehning

4. Loss Distribution in the IP 7 Dispersion Suppressor
Team R. Assmann
Losses of off momentum particles (first and second dispersion increase)
Concentration of losses at the beginning of MQ
BLM on MB foreseen
Beam
LTC, B.Dehning

5. Loss Distribution in the ARC 7 to 8
Increase of losses approaching a MQ
Peak in bin just before MQ
End of loss at the centre of the MQ
Basic assumption: transient losses will have same signature
More simulation are needed to get better evidence (higher populated tertiary halo)
Only beam 1 simulated yet
May automatic online loss characterization possible (location, cause, beam I+II)
Team R. Assmann
Beam
LTC, B.Dehning

6. Change of Aperture at MQ
Losses enhanced at beginning of quadrupole, due to:
Beta function maximums
Dispersion function maximums
Misalignments (location of bellows
Beam kinks (quadrupole + cor. dipole location)
Change in aperture
Beam I
Beam II
LTC, B.Dehning

7. Shower development in the Cryostat
L. Ponce
Impact position varied along the MQ
Highest signal from loss at the beginning of the MQ
Position of detectors optimized
to catch losses:
Transition between MB – MQ
Middle of MQ
Transition between MQ – MB
to minimize uncertainty of ratio of energy deposition in coil and detector
Beam I – II discrimination
Beam
LTC, B.Dehning

8. Simulated BLM Signals at Collimators
Simulation of BLM signal and crosstalk at IP3
Equivalent Simulation for IP7 started (team: A. Ferrari)
signal
signal
crosstalk
LTC, B.Dehning

9. BLM Signal from Upstream Collimator
Igor A. Kurochkin
BLM3 (close to TCS2) – only 57.4% “Good” signal
BLM2 – 4%
BLM4 – 9%
BLM5 – 5%
BLM6 – 4%
BLM7 – 1%
TCP1 - major contributor to background
BLM2 – 96%
BLM7 – 20%
7 TeV
TCP 1
TCS 1
LTC, B.Dehning

10.
LTC, B.Dehning

11. Transversal Variation of Monitor Location
TCS1
Igor A. Kurochkin
Best signal to cross talk at position near to the beam
Foreseen detector position to be changed if simulation indicate unacceptable signal to crosstalk ratio
Detector pos.
beam
LTC, B.Dehning

12. Available Beam Loss Information's
Used threshold values (change with energy)
Loss signals:
Max values of integration intervals between 40 us and 1s updated every 1 s
Several average values between 1s and 60 s updated every second
Long term averages
Post Mortem values
LTC, B.Dehning

13. Beam Dump at HERA Aim of setup LHC measurement setup BLM system test
Verification of Geant simulation
Beam losses dynamic observations
LHC measurement setup
6 chambers in top of internal dump
1 before and 1 after the dump
LTC, B.Dehning

14. Dose Measurements at the HERA Beam Dump
Protons:
1 1013
E = 920 GeV
Peak corresponds to 1.5 Gy
No gain switch
Over 7 orders foreseen
LTC, B.Dehning

15. Dose Measurements at the HERA Beam Dump, zoom
LTC, B.Dehning

16. Reserve Slides
LTC, B.Dehning

17. HERA DUMP Signal
LTC, B.Dehning

18.
LTC, B.Dehning