[r. alemany] [cern ab/op] [engineer in charge of lhc ] lectures at nikhef (12.12.2008)
DESCRIPTION
[R. Alemany] [CERN AB/OP] [Engineer In Charge of LHC ] Lectures at NIKHEF (12.12.2008). The Large Hadron Collider Contents: 1. The machine II. The beam III. The interaction regions IV. First LHC beam. III. First LHC beam. Contents: Injection test 1 Injection test II Injection test III - PowerPoint PPT PresentationTRANSCRIPT
The Large Hadron ColliderContents:
1. The machineII. The beam
III. The interaction regionsIV. First LHC beam
[R. Alemany][CERN AB/OP]
[Engineer In Charge of LHC]Lectures at NIKHEF (12.12.2008)
III. First LHC beamContents:I. Injection test 1II. Injection test IIIII.Injection test IIIIV.10th September
IV.1. Injection Test 1
8 to 10.08.2008
IV.I. Injection Test 1 Achieved
Synchronization SPS – LHC Beam 1 injected IP2 Through to collimators in IP3 first shot Trajectory correction Kick-response measurements Off-energy measurements (dispersion) Explored the aperture First beam induced quench
Discovered Aperture restriction in the injection line
Traced to misaligned vacuum pump Optics problem IP3
Polarity convention QTL
IV.II. Injection Test 2
22-24.08.2008
IV.II. Injection Test 2 Achieved
Beam 2 injected IP8 Through to collimators in IP7 first shot Trajectory correction Kick-response measurements Off-energy measurements (dispersion) Explored the aperture Beam 1 injected IP2 Through to collimators in IP3 Aperture in injection region OK Polarity correction confirmed Interleaved injection
Discovered Optics problem at the end of the TI8 line
I.I. Basic layout of the machine: quadrupole corrector magnets
LHC TDR
Fo
Do
MSCB
MCBM (dipole):Nominal main field strength = 2.93 TInominal = 55 A, 1.9 K, L=78.5 cm, ~143 kg
MSM (sextupole):Nominal main field strength = 4430 T/m2
Inominal = 550 A, 1.9 K, L=45.5 cm, ~83 kg
ChromaticityOrbit
Explore a range of particle angles (=kick strength) with one corrector dipole, then go to the next one
IV.II. Injection Test 2Beam 1 injected IP2Through to collimators in IP3Aperture in injection region OKPolarity correction confirmedInterleaved injection
DiscoveredOptics problem at the end of the
TI8 line
IV.III. Injection Test 3
5 – 7.09.2008
IV.III. Injection Test 3 Achieved
Beam 2 injected IP8 Threaded to dump in IP6 Steered then inject and dump Beam 1 injected IP2 Threaded through to coll in IP5
Discovered Optics problem in IP7
Polarity convention on Q6 Optics problem in IP4
Polarity convention
IV.IV. 10th of September
10.09.2008
IV.IV. 10th of SeptemberAchieved
Beam 1 injected IP2Threaded around the machine in 1hTrajectory steering gave 2 or 3 turns
Beam 2 injected IP8Threaded around the machine in 1h30Trajectory steering gave 2 or 3 turnsQ and Q’ trims gave a few hundred turns
IV.IV. 10th of SeptemberBeam 1 – First turn
trajectory
Each point is a BPM (Beam Position Measurement)
49 mm apertureARC BPMs
Betatron oscillation
IV.IV. 10th of September Beam 1 on TDI screen – 1st and 2nd
turns
ALIC
E
IV.IV. 10th of September Beam 2 – First turn
trajectory
Horizontal position (mm)
Vertical position (mm)
IV.IV. 10th of September Beam 2 – first turn dispersion
measurement
ppsDx x
)(
RF
IV.IV. 10th of September Beam 2: Longitudinal Bunch Profile
~ 200 turns
IV.IV. 10th of September Beam 2 closed orbit
IV.IV. 10th of September Beam 2 beta measurement
QF
QD
IV.IV. 10th of September Beam 2 beta measurement
Reminder from BH lectures
IV.IV. 10th of September Beam 2 integer tunes
Qx = 64
Qy = 59
IV.IV. 10th of September Beam 2 tunes
Qx = .279Qy = .310
BPM pos FFT tune
IV.IV. 10th of September Beam 2 fast BCT (Beam Current Transformer)
FBCT
Inte
nsity
~ 3 109
IV.IV. 10th of September Beam dilution on dump block
~ 8 m
concrete shielding
Beam Dump Block (graphite)
IV.IV. 10th of September Beam 2 captured – mountain range
display
Now RF ON
Bunch length
Turn
num
ber
IV.IV. 10th of September Fast start 10, 11 and 12
All done in 3 days Made possible by
Meticulous preparation Magnetic model data Sophisticated settings generation Dry runs Injection tests
Powerful control system (LSA) Powerful instrumentation working very quickly Logging a multitude of parameters
Allowed early look at several machine parameters systematic check of orbit system
IV.IV. 10th of September