Sector Test Meeting 08.05.2014
LHC Sector Test 2014 web page:
Meetings and minutes:
https://lhcsectortest2014.web.cern.ch
http://indico.cern.ch/event/316394/
Agenda:
1. Collimation Configuration for sector tests and beam measurements. Belen
Salvachua
2. Beam transfer - sector test plan and measurement requests. Wolfgang
Bartmann
1. Collimation Configuration for sector tests and beam measurements
Belen started the presentation with an overview of the collimator system in
2014 and the current status of the installation phase. 32 new collimators will be
installed or moved during LS1:
 16+2 collimators with beam position monitors:
o TCTPH.4R1, TCTPV.4R1, TCTPH.4L1, TCTPV.4L1,
o TCTPH.4R2, TCTPV.4R2, TCTPH.4L2, TCTPV.4L2,
o TCTPH.4R5, TCTPV.4R5, TCTPH.4L5, TCTPV.4L5,
o TCTPH.4R8, TCTPV.4R8, TCTPH.4L8, TCTPV.4L8,
o TCSP.A4R6, TCSP.A4L6
 4+4 physics debris:
o TCL.4R1, TCL.6R1, TCL.4L1, TCL.6L1
o TCL.4R5, TCL.6R5, TCL.4L5, TCL.6L5
 1 TCP (primary collimator):
o TCP.B6R7
 3 TCPs moved due to ventilation work in IR7:
o TCP.B6L7, TCP.C6L7, TCP.D6L7
 2 new passive absorbers in IR3:
o TCAPD.A5L3.B1 TCAPD.A5R3.B2
Currently IR3, IR6 and IR7 are completed; those are the collimators relevant for
the Sector Tests.
The installation of the TCTPs (and TCL6 if possible) will last until July 2014.
Commissioning in the tunnel has started and remote commissioning from CCC
will start as soon the collimators are available after individual system test. By the
time of the Sector Tests all the collimators will be commissioned.
The pilot bunches at the Sector Tests will be stopped with the same technique
used already in previous sector tests called OVERSHOOT:
 Place collimators with the minimum possible gap between jaws on anticollision switches (to avoid the jaws touch each other)  0.5 mm
 Move the collimator position 5 mm aside from the reference orbit to
assure the beam doesn’t have any chance to go through the jaws gap, but
it impacts fully on one of the jaws.
 If required, the collimator can be tilted to leave no clearance.
Belen showed that Tungsten collimators (like TCLAs) are the most effective to
stop the beam; after 1 m of W collimator only around 0.005% of the beam is left.
On the contrary, Carbon collimators are less efficient, since after 1 m of C
collimators, 10% of the beam remains still.
Belen review the collimators used during the injection tests in 2008; those are
summarized in Table 1. Open settings means the collimator is fully retracted to
let the beam go through. Intermediate settings correspond to gaps of the order of
+/-10 and +/-12 mm depending on the collimator.
Beam 1 stopped at LEFT of IR3
Beam 1
Beam 1 stopped at RIGHT of IR3
Beam 1
Beam 2 stopped at RIGHT of IR7
All IR7 collimators closed with
overshoot technique
TCLA.A6L7 (W collimator) overshoot
Beam 2 stopped at LEFT of IR7
Beam 2 dumped in IR6
Beam 2
Table 1: Summary of collimators used for the different injection tests in 2008
with the corresponding type of settings. The arrows indicate the direction of the
beam.
Assuming the same beam conditions as in 2008, single pilot bunches of <= 5 109
protons/bunch, and the same optics, we can use the same collimator
configuration to stop the beams during the 2014 Sector Tests.
Discussion:
During Belen presentation it was mention a specific test to measure the BLM
response in IR3. This required different collimator configurations in IR3 in order
to trigger the beam dump by different BLMs and measure the BLM response and
the latency between the BLM dump request and the LBDS dump. The latency
data can be extracted from the Post Mortem data of both systems. Although is
quite a simple test to do with circulating beam, it was agreed on that it could
already be done, as in 2008, during the Sector Tests. This time will be done with
both beams. Beam 1 will no reach the beam dump system, but it can trigger,
nevertheless, the beam dump. Christos Zamantzas asked if it is possible to have
for each collimator configuration for the BLM latency test, the list of collimators
and their settings recommended by the collimator team well in advance.
Reyes asked if specific tests with the BPM collimators in IP2, IP8 and IR6 can be
done during the Sector Tests. Belen replied she needs to check.
Actions:
1. Collimator team should provide with a list of collimators settings for the
BLM latency tests.
2. The BLM latency test has to be added to the measurement list.
2. Beam transfer - sector test plan and measurement requests
Wolfgang started the presentation specifying the scope of the BT tests for sector
tests:
1. Realignment of relevant machine elements
2. Many systems have been modified (MKI coating, TMR, MKD generators,
…) so magnet settings as from RUN I might not be applicable.
3. We can test the functionality of such a crucial equipment and software
before beam commissioning
4. We can scan kicker waveforms, test TL stability and set up the kicker
timing.
5. SPS extraction channel aperture can be measured, but for optimum
settings for kicker and bumps INDIV is needed.
6. Pilot trajectories and intensities are not suitable for the alignment of
collimators or TDI, again, INDIVs and circulating beam, respectively, is
needed.
The installation and commissioning plan for the injection kickers was presented
as well and it is summarized in the following table:
Activity
IP2 (Week)
IP8 (Week)
Installation
21
35(1)
Bake-out interconnects
22-26
36-40
Controls commissioning
27-28
41-42
Hardware tests
29-30
43-44
Tests from CCC
31-43
45-46
Sector Test
44
47(2)
(1) This date is driven by the fact that there is no access possible before that due to other
shutdown activities.
(2) MKI8 seems to have a tight schedule.
Concerning (2) Verena said that we should take into account that MKI for B1
would have been commissioned before so all the possible common issues, the
software, the control from CCC will be debugged and the two allocated weeks for
CCC tests should be more than enough to have the system ready for week 47.
Wolfgang presented a comprehensive list (Table 2) of tests with beam to be done
for transfer lines, injection and dump systems during the Sector Tests.
Test category
SPS extraction
Description
1.
2.
Establish downstream 1.
2.
TL trajectory
Injection
3.
4.
5.
6.
1.
2.
3.
4.
5.
6.
7.
8.
Beam dump
1.
2.
3.
4.
5.
6.
MKE waveform scan
Rough aperture check if not yet done
Screens matching
Check BPM/corrector polarities (and optics) with kick
response
Measure TL dispersion
Set TCDI
Check automatic setup application
Trajectory stability
Threading through injection region onto closed TDI
Set TDI, TCLI
Aperture in injection region
Orthogonal steering
MKI waveform scan (screen conductors have been
change and there is the issue of TMR aging)
MKI synchronization
AGK synchronization
IQC injection oscillation interlock (needs circulating
beam)
Synchronization
Rough check of extraction channel aperture
BTVD/BTVDD image
Test 14/15 MKD knob
MKB waveform (check with ~ 5 pilots)
MKD waveform (never tested before, need to setup a
procedure)
Table 2: Test with beam to be performed during the Sector Tests.
Without beam
The pre-requisites for those tests to be possible are summarized in Table 3.
Equipment
MKI
Magnet systems
BI systems
Optics
Test description
1.
2.
3.
1.
2.
3.
1.
2.
3.
Open valves, conditioning to 55 kV, softstart
Check BETSim input, SMP energy transmitted
Check MKI waveform logging in OASIS, IQC
Heat run
Pulsing full line
Switch powering
Movements, acquisition, logging, fixed displays
Screens, BPM, BCT, BLM
SPS extraction region (new monitors), TL and LHC
injection/extraction region
1. Check settings for SPS extraction, TL and LHC
injection/extraction systems
2. Beam position on injection/dump region screens
3. TCDI and MKI validation knobs, 14/15 MKD
Protection devices:
TCDI, TDI, TCLI,
TCDQ, TCSP
Interlock
Radiation
monitoring
Quality checks:
IQC, IPOC
BIS loop
closed(2)
1. Downstream TED master BIC, injection permit TT40
2. Inhibit of MKE in case of MKI erratic
Radmons, Ramses in injection/extraction region, logging
TSU - BIS
1. Data reception and logging
2. Element strengths and limits (thresholds to be
updated later)
3. Element updates, new BLMs in injection regions
4. New BETS interlock on MSI, TDI(1)
1. Arming sequence with global BIS
2. LBDS settings and MCS (generators have changed)
3. BETSsim (Q4, MSD input)
4. XPOC:
a. Waveforms, VAC, BTVDD, BPMD (need a
beam dumped event)
b. BLMs (new BLMs and filters)
c. BETS interlock TCDQ
Test of new TSU to BIS link
Sequence
Inject and dump
SPS extraction to
upstream TED
1. Setup extraction bump without extensive aperture
scan
2. Steer through extraction channel
3. Check beam on screens
4. Kicker (MKE) timing in OASIS  need BCT+MKE(3)
Beam dump
With
beam(3)
extraction knobs
4. Aperture bumps at MSI, TCDIM, MKI, Q5, D2 and
TCDQ
5. Screens matching application
Movement, function/range
Table 3: Required preparation for the sector tests.
Discussion:
(1) New BETS interlock on MSI, TDI:
A new BETS interlock on MSI and TDI has been created for RUN II. It is a
MASKABLE BIS input. For changing the HW limits access to UA while MSI is
powered in needed. Detailed discussions are still needed in order to come out
with a procedure for HW limits changed because the MSI is one of the EIS
(Element Important de Securite) and once it is in the access chain, access to LHC
with the MSI powered is not possible.
(2) BIS loop closed:
Wolfgang asked if we foresee time before the sector test with the BIS loop closed.
Stephan Gabourin replied that by September the BIS team will have all installed
and they are flexible to close the loop whenever we schedule the time to test it.
(3) Preparation test with beam:
Wolfgang asked if the TL can be tested until the downstream TED before the
sector test. Reyes replied that this will imply that we have to close the LHC
machine in IP2 and the two adjacent sectors putting on hold any other shutdown
activity in those areas. There are already three slots for Sector Tests in the
planning, so seems difficult to request another one. Verena added that
nevertheless, the first sector test includes time for TI2 and TI8 setup, and beam
to upstream TED in those lines is already foreseen before that, although no date
is still fixed. In case problems are found that compromise the sector tests, there
is the reserved weekend of week 50 to revisit the failed tests.
Actions:
1 Transfer line team has to define a procedure for changing the HW limits
once the MSI is on access chain, may be in coordination with access team.
2 LHCb requested 5 to 6 hours of shots on TDI to do the BCM calibration 
to be included in the measurement program.
3 ALICE requested few shots in TDI to do cross-calibration of the new BLMs
and BCM to be included in the measurement program.
4 We have to add task to select the RF bucket to be injected in the Inject and
Dump sequence.
5 To be checked by TL team if there will be a heat run of the TL magnets.
6 TL team should provide the Sector Test team with a draft program of the
beam measurements that includes when, how long, who is responsible.
7 Sector Test team should add explicitly on the agenda dates for testing
closure of the BIS loop, at least the part needed for the sector tests. This
will allow performing the tests (TSU-BIS link and Inject and dump
sequence) needed for BT.