1. Installation, storage and removal of the TAN detectors during the LHC operation
A.-L. Perrot, TS/LEA-int
LEMIC
A.L. Perrot – TS/LEA/int
LEMIC
20/03/2007

2. Installation – e.g. LHCf on 15 January 2007
Holding of the detector towards the TAN slot
Insertion inside the slot ( guide lines)
Insertion inside the slot
Removal of the threaded rod
A.-L. Perrot, TS/LEA-int
LEMIC

3. Installation – e.g. BRAN housing on 22 January 2007
Holding of the detector towards the TAN slot
Removal of the
threaded rod
Insertion inside the slot
A.-L. Perrot, TS/LEA-int
LEMIC

4. Comments of Radioprotection team
- SC/RP agreed use of forklift for start-up installation and low luminosity run (L<1030 cm-2 s-1)
- for higher doses rates => - study to optimise the intervention
- remote procedure study
Contact with TS/IC/IS (K.Kershaw) in charge of the remote handling for the LHC element
120
A.-L. Perrot, TS/LEA-int
LEMIC

5. Installation of the detectors - run scenario
Point 1
LHCf :
Phase-1: Parasitic running during LHC commissioning at L< 1030 cm-2 s-1
(radiation hardness => LHCf removed when L=1030 cm-2 s-1)
Phase 2: Parasitic running with TOTEM (L=10 28 cm-2 s-1)
(radiation hardness => LHCf removed at the end of the run)
BRAN: Installation before LHC closure - run during all LHC lifetime
ATLAS ZDC: Low L pp runs (“removed for pp run at L>1033 cm-2 s-1 “) + heavy ions runs
Point 5
CMS ZDC: Low L pp runs (1033 cm-2 s-1) + heavy ions runs
LHCf, ATLAS ZDC, CMS ZDC => installs./removals during LHC runs BRAN= always in the TANs
A.-L. Perrot, TS/LEA-int
LEMIC

6. Parameter evolution and rates
All values for nominal emittance, 7TeV and 10m * in points 2 and 8
Parameters
Beam levels
Rates in 1 and 5
Rates in 2 (and 8) kb N
* 1,5
(m)
Ibeam
proton
Ebeam
(MJ)
Luminosity
(cm-2s-1)
Events/
crossing 43
4 1010 11 2
<< 1
0.15
0.76
156 7
9 1010 16
3.9
0.77
936 42
0.73
6 1010 63
1.6
0.34 1 94
2808
126
0.72
5 1010
157
2.1
0.24
0.55
3.6
A.-L. Perrot, TS/LEA-int
LEMIC
R. Bailey talk at the ‘joint LHC Machine – Experiments workshop on very forward detectors’, CERN, 25/01/2007

7. LHC run scenarios considered in our studies
(conservative scenarios from the point of view of the radiation environment)
First year (scenario 1)
Lpeak=2.9x1032 cm-2 s-1 (b*=2m, 75ns operation, Np/bunch=6x1010);
133 days of collisions
e for physics =40% (LEP data)
If everything is going well: 25 ns operation, b*=1m and Np/bunch=5x1010
=> Lmax = 1.1x1033 cm-2 s-1 at the end of the run
2nd year (scenario 2)
Lpeak=1.9x1033 cm-2 s-1 ( (b*=0.55m, 25ns operation, Np/bunch=5x1010);
160 days of collisions
e for physics =40%
After the collimators phase II and the completion of the dump syst.
(scenario 3)
Lpeak= Lnominal= 1034 cm-2 s-1
=> 53 days of physics
=> 64 days of physics
=> 64 days of physics
A.-L. Perrot, TS/LEA-int
LEMIC

8. Detectors removal/insertion from the TAN
- Radiation hardness:
ATLAS and CMS : confirmation that ZDCs can stand the 2nd year scenario for pp and HI
=>ZDCs not removed until we switch to scenario 3
- Bake-out: for all detectors removal / storage underground?
- LHC machine at nominal conditions:
At ~ L=1033 cm-2 s-1, removal of ZDCs => Cu bars in for runs at L≥1033 cm-2 s-1
Heavy ions runs: ZDCs inserted inside TAN => removal of Cu bars
- Obviously: if any problem happens with the ZDC it will have to be removed.
A.-L. Perrot, TS/LEA-int
LEMIC

9. Radiation environment - Detectors average residual dose vs time
Averaged over tungsten
LHCf
Simulations by N. Mokhov
100days
100days
ZDC
L=1030 cm-2 s-1
L=1033 cm-2 s-1
mSv/h
mSv/h!!
A.-L. Perrot, TS/LEA-int
LEMIC

10. Radiation environment at the TAN during LHC runs
Averaged over copper bars
mSv/h!!
100 days
30 days
A.-L. Perrot, TS/LEA-int
LEMIC

11. Installation foreseen with CERN forklift
Point 1 (RI132-RI171)
- Access by Pt1:
Shielding between UJ13-UJ14, and between
UJ16-UJ17 => forklift too large to pass
- Access by Pt 2 and Pt8:
=>Travel underground until TANS (study by O. Choisnet TS/MME)
Courtesy of O. Choisnet (TS/MME)
Pt5 (UJ53 –R571)
- Access by Pt5:
only a ‘normal persons’ lift => forklift too large to pass
- Access by Pt4 and Pt6:
=>Travel underground until TANS
Forklift
Detectors: via PMs?
A.-L. Perrot, TS/LEA-int
LEMIC

12. Summary and open issues
- ZDCs & Cu bars need to be installed and removed
- Dose rates according to operational scenarios : up to mSv/h
=> remote handling needed to reduce the dose to the personnel.
Logistic:
- installation foreseen with a forklift
(at Pt1 lowering via pit =possible; at Pt5 not such a possibility)
- long travel along cold machine and in radioactive environment
- storage of detectors / Cu bars underground (where, how long time)?
- possible storage of dedicated forklift in UJs/ access with detectors by Pt1 &5?
A.-L. Perrot, TS/LEA-int
LEMIC