CNGS ISSUES - THAT COULD DISTURB A SMOOTH OPERATION IN 2009 Thanks to colleagues who contributed to...
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Transcript of CNGS ISSUES - THAT COULD DISTURB A SMOOTH OPERATION IN 2009 Thanks to colleagues who contributed to...
CNGS ISSUES - THAT COULD DISTURB A SMOOTH OPERATION IN 2009
Thanks to colleagues who contributed to the slides:E. Gschwendtner, A. Pardons, H. Vincke, S. Girod, D. Autiero, R. Losito
ATOP DaysCERN March 6, 2009
Outline
• CNGS run in 2008 – overview
• 2008 shutdown – major works• Horn/reflector cooling system• Waste water handling
• Prospects for the 2009 run
I. Efthymiopoulos, EN/MEF
CNGS Run in 2008
Smooth running, excellent performance of the facility No radiation problems/effects in the electronics
No problems with the major elements of the secondary beam: target, horn/reflector
OPERA Experiment 10’100 on-time events 1’700 candidate
interactions in the bricks
I.Efthymiopoulos, EN/MEF
2
ATOP Days, March 2009
Performance
Average rate
Reference sample:
Long tracks (>5 TT planes × 20)
CNGS on time events
3
CNGS Run in 2008
I.Efthymiopoulos, EN/MEF
Primary beam
48s supercycle : FT + 3 CNGS + LHC + MD 37.5% CNGS duty cycle
50.4s supercycle : 7 CNGS + LHC 83% CNGS duty cycle
Integrated efficiency: 60.94%
ATOP Days, March 2009
Physics run in 2008
I.Efthymiopoulos, EN/MEF
Beam statistics4
18kV cable repair
MD
PS magnet exchange, septum bakeout
MD
SPS timing fault:vacuum leak & magnet exchange
CNGS maintenance:Horn water filter exchange,Hadron stop sump emptying
SPS extraction line: Magnet ground fault
1.78E19 pot on November 3rd
Integrated protons on CNGS target
1.4E19
4.0E18
8.0E18
6.0E18
1.0E18
2.0E18
18-June July 2008 August 2008 September 2008 October 2008
MD
CNGS maintenance:Horn water filter exchange
1.0E19
1.2E19
1.6E19
November2008
ATOP Days, March 2009
Protons on Target per DayBeam to CNGS, North Area, LHC Beam to CNGS only
0.0E+00
4.0E+16
8.0E+16
1.2E+17
1.6E+17
2.0E+17
2.4E+17
2.8E+17
3.2E+17
3.6E+17
4.0E+17
16-J
un
21-J
un
26-J
un
1-J
ul
6-J
ul
11-J
ul
16-J
ul
21-J
ul
26-J
ul
31-J
ul
5-A
ug
10-A
ug
15-A
ug
20-A
ug
25-A
ug
30-A
ug
4-S
ep
9-S
ep
14-S
ep
19-S
ep
24-S
ep
29-S
ep
4-O
ct
9-O
ct
14-O
ct
19-O
ct
24-O
ct
29-O
ct
3-N
ov
8-N
ov
po
t/d
ay
0.0E+00
4.0E+18
8.0E+18
1.2E+19
1.6E+19
2.0E+19
2.4E+19
2.8E+19
3.2E+19
3.6E+19
4.0E+19
inte
gra
ted
po
t
CNGS duty cycle: 37.5%, 54% 37.5%, 43% 37.5%,45%,54%
56%-83%
3.5E17
CNGS Facility – Performance 2008
E. Gschwendtner – AB Seminar Nov’08
Target Beam Position• Excellent position stability; ~50microns over entire run.• No active position feedback is necessary
– 1-2 small steerings/week only
CNGS Facility – Performance 2008
Horizontal beam position on the last BPM in front of the target
E. Gschwendtner – AB Seminar Nov’08
Beam Stability seen on Muon Monitors• Position stability of muon beam in pit 2 is ~3cm rms• Beam position correlated to beam position on target.
– Parallel displacement of primary beam on T40
Horizontal centroid pit 2 Vertical centroid pit 2
CNGS Facility – Performance 2008
E. Gschwendtner – AB Seminar Nov’08
8
Muon MonitorsVery sensitive to any beam changes !
– Offset of beam vs target at 0.05mm level
CNGS Facility – Performance 2008
Muon Profiles Pit 1
Muon Profiles Pit 2
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
10
/29
0:0
0
10
/29
0:2
8
10
/29
0:5
7
10
/29
1:2
6
10
/29
1:5
5
10
/29
2:2
4
10
/29
2:5
2
10
/29
3:2
1
10
/29
3:5
0
10
/29
4:1
9
10
/29
4:4
8
10
/29
5:1
6
10
/29
5:4
5
10
/29
6:1
4
10
/29
6:4
3
cm
5cm shift of muon profile centroid
~80mm parallel beam shift
Centroid of horizontal profile pit2
– Offset of target vs horn at 0.1mm level• Target table motorized• Horn and reflector tables not
E. Gschwendtner – AB Seminar Nov’08
ATOP Days, March 2009
9
CNGS Run in 2008
I.Efthymiopoulos, EN/MEF
Very interesting experience to stress the facility duty cycle : up to 83% (1-2 days only), with ~75-80% of designed pulse intensity Note:
CNGS design of equipment and RP considerations for 2×2.4×1013 protons/6s, 100% duty cycle Target design with ×2 safety for “ultimate” intensity of 2×3.5×1013 protons/6s, 100% duty cycle
Observations: No unexpected temperature rise in horn/reflector and electrical circuit
Several temperature probes (mainly around the target station) died Expected, due to integrated intensity Action : nothing to do!
Increased temperature at the first He-tank window Action : not an issue, should be kept in mind for future (upgrades?)
Lifetime of horn/reflector cooling circuit filters Understood, due to integrated intensity but shorter than expected No degradation of horn/reflector itself Action : work during 2008/09 shutdown
High-duty cycle operation
10
CNGS duty cycle: 37.5%, 54% 37.5%, 43% 37.5%,45%,54%
56%-83%
Helium Tube Entrance Window TemperatureCNGS Facility – Experience of Operating a 500kW Facility
E. Gschwendtner – AB Seminar Nov’08
Helium Tube Entrance WindowTemperature
Measurements
– 0.3mm thick– 0.8m inner
diameter– Clamped with seal
between flanges
shielding
shielding
horn
ionization chamber
ionization chamber
targetTBIDcollimator
BPM
beamHelium tube
Ti-
win
do
w
Temperature Measurement
Clampingbolt
Entrance window
SealTitanium Grade (Ti-6Al-4V)– Ultimate stress:
– @20°C: >900MPa– @100°C: >870MPa– @150°C: >850MPa
From calculations:- When ventilation vs. beam is such that temp. at flange = 66°C:
Window: Temp. <100°C & Stress <250MPa Safety factor 3 ensured.
From temperature measurements during operation (extrapolate):- If temp. measured < 85°C
Window: Temp. <150°C & Stress <300MPa Safety factor 2.5 ensured.
CNGS Facility – Experience of Operating a 500kW Facility
Courtesy of A. Pardons
ATOP Days, March 2009
12
CNGS Run in 2008
I.Efthymiopoulos, EN/MEF
Helium Tube Entrance Window
Horn
Beam
He window
CNGS Run in 2008
TBID detector broke down on July 19, only after 1.2×1018 pot) the ionization chambers can be used for setting up reduced handle to verify target integrity and beam steering
I.Efthymiopoulos, EN/MEF
13 TBID Detector
0
2
4
6
8
10
12
14
16
18
20
7/19
0:0
0
7/19
1:0
5
7/19
2:1
1
7/19
3:1
6
7/19
4:2
2
7/19
5:2
7
7/19
6:3
3
7/19
7:3
8
7/19
8:4
4
7/19
9:4
9
7/19
10:
55
7/19
12:
00
7/19
13:
06
7/19
14:
11
date
mu
ltip
licit
y
1.0E-01
1.2E-01
1.4E-01
1.6E-01
1.8E-01
2.0E-01
2.2E-01
2.4E-01
ch
arg
es
/po
t
TBID signal
Ionization Chamber
ATOP Days, March 2009
Origin of the problem Short circuit in the
isolation bias of the screens
Could be either in the cable, the connectors, or in the device itself
ATOP Days, March 2009
14
CNGS Run in 2008
I.Efthymiopoulos, EN/MEF
TBID Detector
TBID
TargetHorn
Beam
Possibility to repair? Radiation levels are rather high
~27mSv/h at floor level Difficult to remove it due to
cables No spare available Review again with BE/BI & RP
before startup if something can be done, also in view of other operations…
Major shutdown activities Repair of the ventilation unit in TCV4
Modifications to the horn/reflector cooling system to improve the filter lifetime
Evacuation and handling of the CNGS sumps water
Inspection of target unit
CNGS Preparation for 2009
I.Efthymiopoulos, EN/MEF
15
ATOP Days, March 2009
TCV4 Ventilation repair
Leak of chilled water in one of the TCV4 units(1st floor) small leak, triggered no alarm, but still ~2.5m3
of water in the floor and on top of equipment
no damages except in one of the cameras
the water became radioactive as it washed the nearby filters of the ventilation unit
Repair ongoing along with standard maintenance of all ventilation units work next to the filters, had to wait for cool-
down
I.Efthymiopoulos, EN/MEF
16
Solutions Difficult to install detection system for such small leaks; small fraction of total water flow in
the CNGS area
Install additional cameras to monitor the TCV4 cavern !!ATOP Days, March 2009
Cooling system for the horns
Resin filters are used to maintain a low conductivity level in the circuit Two reasons:
avoid short-circuit inside the horn limit long-term corrosion effects
About 1/3 of the flow goes through the filters Required level: [0.1,10.0]mS/cm
Two filters in place (active + spare) equipped with quick connectors Filters get activated – temporarily stored in TSG4 for
initial cool-down
Main issues: Filter lifetime before saturation
wished to be one year, but really unknown 2008 run showed they saturate much sooner !! long access (>20h stop) each time to replace them
(10min) The filters used have plastic pieces (tubes) inside; not a
real issue but better to avoid The filters are radioactive waste, their use must be
optimizedI.Efthymiopoulos, EN/MEF
17 Filters
ATOP Days, March 2009
Cooling system for the horns
I.Efthymiopoulos, EN/MEF
18 Filter lifetime - horn
Filter exchange
Filter exchange
Limit for safe operation : 10mS/cm
7.5E18 pot
45 days
This would imply ~6 filter exchanges for a nominal CNGS year (4.5×1019 pot) !
Water conductivity
Inte
grat
ed p
ot
ATOP Days, March 2009
Cooling system for the horns
I.Efthymiopoulos, EN/MEF
19 Filter lifetime - reflectorFilter
exchange
Filter exchange at 1.15E19 pot 4 filter exchanges/y @ (4.5×1019 pot) !
ATOP Days, March 2009
Cooling system for the horns
I.Efthymiopoulos, EN/MEF
20
Increase the filter capacity of the system use 2 × 50(100) lt filters instead of single 40lt today × 2.5 gain, survive a full nominal year with only one exchange
New optimized filter container design allow easier manipulation (installation/removal) of the filters maintain the quick connectors possibility to empty the resin and re-use the container less
radioactive waste
design to be validated by safety and RP
Modifications for 2009
ATOP Days, March 2009
Cooling system for the horns
I.Efthymiopoulos, EN/MEF
21 Horn/reflector cooling system – modifications shutdown 2009
draf
t des
ign
ATOP Days, March 2009
New chassis to add to existing one Enough space for 2(3) cartridges of
50(100) lt
Additional metallic filter to capture resin debris in case of an accident
CNGS sumps
I.Efthymiopoulos, EN/MEF
22 Layout
ATOP Days, March 2009
CNGS water handling
1. Sumps TNM41 – TNM42 infiltrations along the decay tube (1-1.5lt/h) – nothing can be easily
done to reduce it Requires access to TI8 line – foreseen during the injector MD periods
2. Sumps in TSG4 water inflow from condensation in the ventilation system : 1 evacuation
during operation, ~4 during shutdown
3. Horn/reflector cooling water 2× 600 lt ; highly radioactive (up to
80 MBq/lt) Yearly exchange
4. Hadron stop cooling water ~2000 lt, highly radioactive
I.Efthymiopoulos, EN/MEF
23
ATOP Days, March 2009
Summary
CNGS water handling
I.Efthymiopoulos, EN/MEF
24
Evacuate the water from the different areas Special equipment for TI8/hadron stop available
Can pass under the vacuum pipe in TI8 tunnel
Transfer the water in special containers for storage
Accumulate the water for one operational year
Elimination path(s) Via CEA Marcoule
A complete chemical analysis needs to be done each time before they can accept the water
Evaporator NUMI uses a such a system for their tritiated alkaline water
can treat 85gallons(320lt)/day of 90’000pCi/ml (3.4MBq/lt) H3 contained water of PH 12-13
Discussions ongoing in a working group with A&T safety and RP colleagues
Plan for 2009
ATOP Days, March 2009
CNGS water handling
I.Efthymiopoulos, EN/MEF
25 Transient water storage in BA4
Retention bag connected to L3 alarm
Foreseen space for 18 containers (18m3)
Isolation against freezing if needed (cost an issue)
ATOP Days, March 2009
TARGET inspection
I.Efthymiopoulos, EN/MEF
26
During the standard maintenance, a problem appeared in the motorization for the target rotation
From investigations so far it seems the torque needed to turn the target unit exceeds the capacity of the motor and the torque limiter
Proposed plan: Open the target shielding to view the status of the target unit with the crane
camera Install a test stand upstream in TCC4 and bring the target unit for further
observations with cameras and if possible prepare tooling to do rotation tests. The EN/STI experts are already working on the spare unit to optimize the
manipulations in CNGS
More news in the coming weeks…ATOP Days, March 2009
TARGET inspection
I.Efthymiopoulos, EN/MEF
27
ATOP Days, March 2009
CNGS target magazine during assembly
TARGET inspection
I.Efthymiopoulos, EN/MEF
28 TCC4 inspection – outside the shielding
ATOP Days, March 2009
Signs of rust are observed in parts of the motorizations and limit switches
Could be the origin of the torque increase To be investigated once the target is out from
its shielding.
TARGET inspection
I.Efthymiopoulos, EN/MEF
29 Target magazine inspection in TCC4
Work in the area to be defined and discussed in collaboration with SC/RP
Lab tests with the spare unit would allow to optimize the time needed in agreement with the ALARA principle
Target magazine in its transport
chassis
Camera locations
ATOP Days, March 2009
Pb screens
CNGS Preparation for 2009
I.Efthymiopoulos, EN/MEF
30
Floor rectification for the traveling of the PPP-TSG41 plug Make new solid flat surface for the big plug to roll
Consolidation/preventive maintenance of horn/reflector power supplies Small consolidation project for 2009/2010
preventive maintenance to replace thyristor capacitance charges cross-check all bus-bars connections and screws to avoid similar incident as last year
Improvements in the irradiation test installation – CNRAD test area Complete installation of all four stations, correct powering problems Support stands for irradiation samples (not laying everything on the floor) Complete RADMON installation and define reference positions Finalize access and material handling procedures
… and
Standard maintenance of various systems
2008/2009 Shutdown activities
ATOP Days, March 2009
LNGS News
I.Efthymiopoulos, EN/MEF
31
OPERA is advancing with the analysis of the 2008 data They accumulated in 2008 about 10000 on time events, mostly interaction
in the rock, among which 1700 neutrino interactions in the bricks They aim in completing the analysis of 2008 data by the start of 2009 run
OPERA looks forward to a smooth run in 2009 with integrated intensity as close as possible to the nominal value of 4.5 1019 pot
They transmit their thanks to all the accelerator teams for their
continuing efforts to support the beam line and the LNGS physics
ATOP Days, March 2009
OPERA Event Gallery
I.Efthymiopoulos, EN/MEFATOP Days, March 2009
32
Charm mesons produced in um interactions 2.1 expected charm events during 2007-2008 Seen: 2 charm-like topologies
Event analysis - preliminary
0
2E+18
4E+18
6E+18
8E+18
1E+19
1.2E+19
1.4E+19
1.6E+19
1.8E+19
18-J
un
28-J
un
8-J
ul
18-J
ul
28-J
ul
7-A
ug
17-A
ug
27-A
ug
6-S
ep
16-S
ep
26-S
ep
6-O
ct
16-O
ct
26-O
ct
5-N
ov
inte
gra
ted
po
t
CNGS – prospects for 200933
33
Beam to CNGS, LHC, FT, MD
Beam to CNGS, LHC, FT
Beam to CNGS, MD
2009 : 175 days with beam
2.80×1019 pot for 2.0×1013 prot/extr
3.36×1019 pot for2.4×1013 prot/extr (MTE)
3.70×1019 pot with 2.0×1013 prot/extr
4.44×1019 pot with 2.4×1013 prot/extr (MTE)
4.80×1019 pot with 2.0×1013 prot/extr
5.76×1019 pot with 2.0×1013 prot/extr (MTE)
I.Efthymiopoulos, EN/MEFATOP Days, March 2009
2008 was a very good year for CNGS Many thanks to those who worked hard during last year’s shutdown, and the operations teams for providing the beam to the facility and
the experiments
2009 shutdown work is advancing well, getting ready for the startup
but still some last minute surprises like with the target
Looking forward for a smooth and efficient run in 2009
Summary
I.Efthymiopoulos, EN/MEF
34
ATOP Days, March 2009