1 PAST ESTIMATIONS ON THE ROLE OF PASSIVE ABSORBERS Francesco Cerutti for the team 2012 June 4th.
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Transcript of 1 PAST ESTIMATIONS ON THE ROLE OF PASSIVE ABSORBERS Francesco Cerutti for the team 2012 June 4th.
1
PAST ESTIMATIONSON THE ROLE OF PASSIVE
ABSORBERSFrancesco Cerutti
for the team
2012 June 4th
2012 June 4th F. Cerutti CWG#142 2
• warm magnets and passive absorbers
• IR7 betatron cleaning
• IR3 combined cleaning
• considerations for IR3 momentum cleaning
OUTLINE
2012 June 4th F. Cerutti CWG#142 3
IP7TCP.D C B 6L7.B1
v h ss
MBW
MQW
TCAPA
beam 1
2012 June 4th F. Cerutti CWG#142 4
[M. Karppinen quoted
by M. Brugger
@CWG#89]
for the MQW
IN IR7
2012 June 4th F. Cerutti CWG#142 5
IR7 BETATRON CLEANING
F. Cerutti @CWG#108 for intermediate collimator
settings
BEAM PIPE
HEATING
beam 1 horizontal
halo
COIL
DETERIORATION
for 1.15 1016
lost protons per beam
peak dose
TCAPA B
CTCAPA B
C
with 3 passive absorbers per
beam
2012 June 4th F. Cerutti CWG#142 6
IR7 BETATRON CLEANING
actual layout with metallic collimator
element peak [MGy] stat. err. [%] peak [MGy] stat. err. [%]
MQWA.E5L7 0.9 10 0.3 20
MQWA.D5L7 0.5 10 0.1 15
SLAC
prototype
[L. Lari]
with an additional metallic collimator
for 1.15 1016 lost protons per beam at 7 TeV (beam 1 horizontal halo)
F. Cerutti Conceptual Design Review Phase II Collimation April
2009
2012 June 4th F. Cerutti CWG#142
hv
hv
with 1 passive absorber per beam
and additional vertical collimators
7
IR3 COMBINED CLEANING
M. Mauri R2E Meeting July 17th
2008
for 1016 lost protons per beam at 7 TeV (beam 1 horizontal halo)
beam 1
2012 June 4th F. Cerutti CWG#142 8
IR3 COMBINED CLEANING
TCP. 6 MBW.C B A 6TCAP
A
MQWA.E D
5
TCAP
C
TCAP
B
MQWA.C
5
IP3TCSG. 5
vh vh
with two additional passive absorbers per beam:
L. Lari CERN-ATS-2001-117 (IPAC
2011)
peak dose [MGy]no additional
TCAPswith additional
TCAPs
element\beam energy
7 TeV 3.5 TeV 7 TeV 3.5 TeV
MQWA.E5L3 7.6 2.8 5.1 1.2
MQWA.D5L3 3.8 1.6 3.1 1.4
MQWA.C5L3 4.8 1.6 2.9 1.0
for 1016 lost protons per beam (beam 1 vertical halo)
high peak also on MQWA.E4R3, just downstream of a pair of (h-v)
collimators
2012 June 4th F. Cerutti CWG#142 9
how many losses? [see Mike’s talk]
Over 2011, the TCP BLM in P3 gives almost a factor of 2 difference between beam 1 and
beam 2
Looking at the P3/P7 sharing, wrt to the first TCP BLM in P7 (vertical collimator quite
doubtful assumption), one gets a factor of 3.5 for beam 1 and a factor of 1.15 for beam 2
FLUKA geometry of IR3 rapidly available, thanks to the new FLUKA Element DataBase and
LineBuilder
which loss maps? (and corresponding collimator settings)
readings of passive dosimeters installed 4 months ago in the locations suggested on purpose
(attached to the beam pipe and the MBW external coils, being not accessible the concerned
internal MQW coils), are expected to provide during LS1 relevant data and related
benchmarking opportunities
IR3 MOMENTUM CLEANING
[data kindly extracted by P. Mala and M.
Calviani]
2012 June 4th F. Cerutti CWG#142 10
CONCLUSIONS
Guessed peak dose values in the MQWA.E-C5 L3.B1/R3.B2 (and possibly MQWA.E4
R3.B1/L3.B2) are not reassuring
Dedicated shower calculations for the standard IR3 momentum cleaning scenario
were not performed, and can in principle – after clarifying loss maps and
normalization assumptions - be launched (manpower shortage will be overcome by
the autumn)
Dedicated measurements have been put in place (with Pierre Thonet, Davide
Tommasini, Julia Trummer) and dosimeter reading could be carried out at LS1
The activation of the area (see Stefan’s talk) challenges a late TCAP installation