LHC Status

Lyndon R. Evans

LHC 2003 / 4th International Symposium on LHC: Physics and detectors

FNAL, 1-3 May 2003

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Civil Engineering at Point 1

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Civil Engineering at Point 5

L.R. Evans, CERN EDMS Document No. 382362

LHC status

• All excavation finished.

• Caverns will be delivered on schedule:

ATLAS 15th April 2003

CMS 1st July 2004

• LHC machine – all CE finished by summer 2003.

Civil Engineering

L.R. Evans, CERN EDMS Document No. 382362

LHC status

• Dipole production is ramping up according to plan.

• CERN-provided components are being stockpiled at a number

of sites.

• Cable production is now at nominal rate after the commissioning

of the new cabling machine.

Dipole Production

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Cable

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Cable

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Dipole

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Dipole

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Dipoles

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Dipoles

Histogram of the number of quenches to reach 8.33 Tesla for the first 28 LHC preseries dipoles

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

0 1 2 3 4 5 6 7 8 notreached

Number of quenches to reach 8.33T

Nu

mb

er

of

ma

gn

ets

01 02 03

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Dynamic Aperture and Field Quality

-15

-10

-5

0

5

10

15

0 10 20 30 40 50 60 70 80 90Magnet number

b3 s

trai

ght pa

rt (un

its)

Firm 1

Firm 2

Firm 3

Collared coil

upper limit for systematic

lower limit for systematic

average

AT-MAS & MTM

L.R. Evans, CERN EDMS Document No. 382362

LHC status

• Saclay-CERN collaboration.

• Two quadrupoles tested, excellent results.

• Quadrupole #11 finished.

• One complete cold mass delivered, second in pressure test,

#3 and #4 under construction.

• Main bottleneck is delivery of correctors, in particular MSCB.

Main Quadrupoles

L.R. Evans, CERN EDMS Document No. 382362

LHC status

• US and Japanese insertion quadrupoles are now well into

production and give excellent results.

• Integration into the inner triplet assemblies at FNAL. Some

delays in CERN-supplied correctors.

• The first beam separation dipole has arrived from BNL.

Insertion Magnets

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Beam Stability

after

before

after

before

after

before

after

before

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Electron Cloud Effect

• Electrons, from synchrotron radiation or ionisation, can be accelerated in the potential well of the bunches, creating secondaries on impact with the beam screen.

• For 25 nsec bunch separation, this can result in an exponential build-up and is a source of heat input into the cryogenic system.

• Electron bombardment has a “scrubbing” effect, reducing the SEY and increasing the threshold. This has clearly been observed in the SPS.

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Electron Cloud Effect

1 .E -22

1 .E -21

1 .E -20

1 .E -19

1 .E -18

1 .E -17

0 24 48 72 96 120 144 168 192 216 240 264 288

Cum ul. tim e (hours)

P /

I ba

tch

0

3

6

9

12

15

I Bu

nc

h (1

010 p

)

50060 (D ipole fie ld)51833 (F ie ld free)Bunch Intensity (x 1E10)

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Electron Cloud Effect

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

2.1

2.3

2.5

0 500 1000 1500 2000 2500 3000

Energy (eV)

SE

Y

4 h

10 h

21 h

63 h

90 h

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Electron Cloud Effect

• Simulations (Zimmermann et al.) now predict many features that can be verified experimentally.

• In the warm regions, the chamber will be coated with a new getter materail, TiZrV (Benvenuti) that activates at much lower temperature (200° C) than conventional getters.

• Once activated, the SEY is low enough to avoid e-cloud build-up.

L.R. Evans, CERN EDMS Document No. 382362

LHC status

Electron Cloud Effect

L.R. Evans, CERN EDMS Document No. 382362

LHC status

• AL 18 kW plants at points 4 and I8 commissioned and accepted.

Linde plants at points 6 and 8 ready for commissioning.

• IHI/Linde 1.8 K compressors in production (four units).

AL prototype under final acceptance.

• QRL (distribution line) on schedule to start installation

16th June.

• Cryogenic feedboxes for magnet test stations, delivery of

3rd and 4th units mid-April.

Cryogenics

L.R. Evans, CERN EDMS Document No. 382362

LHC status

TT40 Transfer Line Installation

L.R. Evans, CERN EDMS Document No. 382362

LHC status

L.R. Evans, CERN EDMS Document No. 382362

LHC status

• The experimental areas and infrastructures will be delivered

on time.

• The LHC machine construction is on schedule for start-up with

beam in April 2007.

Conclusion