|
Step
|
Activity
|
Who |
Priority
|
|
A.6.1
|
Preparation
(single beam, one beam at a time, B1 first) |
OP |
1
|
|
A.6.1.1 |
Preparation of sequencer:
injection for both beams |
|
|
|
A.6.1.2 |
Bucket selection |
|
|
|
A.6.1.3 |
Verify that beam is injected into
bucket 1 |
|
|
|
A.6.1.4 |
Verify that radial offset is similar
in both rings |
|
|
|
A.6.2 |
Optimize
correctors settings |
OP |
1 |
|
A.6.2.1 |
Inject first beam: zero or minimize common corrector
settings |
|
|
|
A.6.2.2 |
Dump beam, inject the second beam
with same common corrector settings |
|
|
|
|
If the other beam does not survive
(if settings of the common correctors have to be different for
the two beams): |
|
|
|
A.6.2.3.1 |
Longitudinally separate the
beams |
|
|
|
A.6.2.3.2 |
Inject both beams and do a
common correction over the insertions |
|
|
|
A.6.3
|
IR set up:
separation bumps, SIS limits (I)
|
ABP/OP |
1
|
|
A.6.3.1 |
Single beam set up of separation bumps:
base bump (base bumps are not orthogonal and will have effect on
both
beams) |
|
|
|
A.6.3.2 |
Inject beam 1 on base bump and
correct orbit without common correctors, dump beam |
|
|
|
A.6.3.4 |
Base bump setting
for other beam (common correctors settings: same as
first beam) |
|
|
|
A.6.3.5 |
Inject the second beam |
|
|
|
A.6.3.6 |
Correct orbit without common
correctors |
|
|
|
A.6.3.7 |
Dump beam, inject both beams |
|
|
|
A.6.3.8 |
Fine tune the separation
with the orthogonal bumps on top of base bumps |
|
|
|
A.6.3.9 |
Dump beam 1, check that BPM and
BLM readings for beam 2 don't change |
|
|
|
A.6.3.10 |
Dump beam 2 |
|
|
|
A.6.3.11 |
Inject both beams |
|
|
|
A.6.3.12 |
Dump beam 2, check that BPM and
BLM readings for beam 1 don't change |
|
|
|
A.6.3.13
|
Dump beam 1
|
|
|
|
A.6.4 |
IR set up:
aperture measurements with separation on |
Coll/ABP/BT |
1 |
|
A.6.4.1 |
Single beam, one IR at a time |
|
|
|
A.6.4.2 |
Verify aperture in the TDI for
non-collimated beam (IR2 and 8) |
|
|
|
A.6.4.3 |
Determine aperture [hence n1]
with closed orbit bumps |
|
|
|
A.6.4.4 |
Fine tune separation with orthogonal
bumps to reach required n1 in triplet |
|
|
|
A.6.4.5 |
Beam dump, repeat with other beam |
|
|
|
A.6.4.6 |
Measure failure scenario with safe
beam (pilot): 7 TeV separation bump for 450 GeV; acquire BLM
profile in insertion, verify protection with BLMs |
|
|
|
A.6.5
|
IR set up:
separation bumps, SIS limits (II)
|
|
|
|
A.6.5.1 |
Inject both beams |
|
|
|
A.6.5.2 |
Verify separation bumps with both
beams stored |
|
|
|
A.6.5.3 |
Measure dispersion with
radial steering and compare to the model |
|
|
|
A.6.5.4 |
Define separation bump reference |
|
|
|
A.6.5.5 |
Set SIS limits on correctors for
injection |
|
|
|
A.6.6 |
Verify beam dump with
two beams |
BT |
1 |
|
A.6.6.1 |
Dump beams
together and check |
|
|
|
A.6.6.2 |
Request planned dump of one beam without the
other and check |
|
|
|
A.6.6.3 |
Verification of BIS loop unlinking |
|
|
|
A.6.6.4 |
Verify PM suppression |
|
|
|
A.6.6.5 |
Verify dump timing and ring |
|
|
|
A.6.6.6 |
XPOC |
|
|
|
A.6.7 |
IR set up:
triplet alignment checks (k modulation) |
ABP/OP |
2 |
|
A.6.7.1 |
Leave separation on |
|
|
|
A.6.7.2 |
Both beams: manual or
pre-programmed k-modulation |
|
|
|
A.6.7.3 |
Define difference of offsets for
the two beams |
|
|
|
A.6.7.4 |
Re-align triplet if necessary |
|
|
|
A.6.7.5 |
Adjust if necessary the
separation bumps accordingly with orthogonal knobs |
|
|
|
A.6.8 |
Fine tune RF phase to guarantee
collisions at IP |
ABP/OP/RF |
1 |
|
A.6.8.1 |
Oscilloscope for time
difference measurements: adjust RF phase such that the difference of
time differences between the two Q1 BPMs sum signals for the two
beams goes to zero |
|
|
|
A.6.8.2 |
Collapse separation bumps → first
collisions (if not, do not insist) |
|
|
|
A.6.9 |
Set up of two beam
collimators (TCTVB, TCLIA) |
Coll/BT |
1 |
|
A.6.9.1 |
Validation of injection protection with 2
beam settings and separation bumps, see A.5.1 and link to
detailed procedure therein (A.5.1.6) |
|
|
|
A.6.9.2 |
Close the jaws with the two beams
circulating, looking at direction of the showers |
|
|
|
A.6.9.3 |
If necessary, adjust in the
horizontal plane to leave the non collimated beam unperturbed
|
|
|
|
A.6.9.4 |
Fine tune the vertical gap (beam
based alignment) |
|
|
|
A.6.9.5 |
Repeat for the next IRs, one IR at a
time |
|
|
|
A.6.9.6 |
dump beams,
re-inject both
beams - verify |
|
|
|
A.6.10 |
Equalize beam
characteristics |
|
|
|
A.6.10.1 |
Measure intensity and lifetime
differences |
|
|
|
A.6.10.2 |
Verify the optics with both beams |
|
|
|
A.6.10.3 |
Equalize beam characteristics acting
on physics parameters (orbit, dispersion, coupling, Q, Q',
collimation, etc) |
|
|
|
|
Completion of
PHASE A.5 is a PRE-CONDITION for the next steps |
|
|
|
A.6.11-12 |
Multi-bunch
operation: initially 12 bunches |
ABP/OP/BT |
1 |
|
A.6.11 |
Equalize beam
characteristics |
|
|
|
A.6.11.1 |
Prepare injectors for interleaved
injections. Either: |
|
|
|
A.6.11.2-a |
2 LHC cycles in the
SPS (no destination) |
|
|
|
A.6.11.2-b |
Or: 1 LHC cycle in the
SPS supercycle (with destination ) |
|
|
|
A.6.11.3 |
Injection matching |
|
|
|
A.6.11.4 |
Verify two beam collimator settings
(TCTVB and TCLI) |
|
|
|
A.6.11.5 |
Measure intensity and lifetime
differences |
|
|
|
A.6.11.6 |
Equalize beam characteristics acting
on physics parameters (orbit, dispersion, coupling, Q, Q',
collimation, etc) as in step A.6.9 |
|
|
|
A.6.11.7 |
Intensity difference before dump:
< 20 % |
|
|
|
A.6.11.8 |
Emittance difference < 40 % |
|
|
|
A.6.12 |
Increase number
of bunches, 43 on 43, then 156 on 156 |
ABP/Coll/BT |
1 |
|
A.6.12.1 |
Verify two beam collimators at each
intensity step |
|
|
|
A.6.12.2 |
Equalize beams and verify optics at each intensity
step |
|
|
|
A.6.12.3 |
check functioning of feedbacks at each intensity
step |
|
|
|
A.6.12.4 |
check beam induced cross talk or noise at each intensity
step (by dumping one beam as in A.6.3.9 |
|
|
|
A.6.12.5 |
Repeat A.6.6
at each intensity
step (verify dump) |
|
|