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


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%


Physics run in 2008


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


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


Horizontal beam position on the last BPM in front of the target


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



8

Muon MonitorsVery sensitive to any beam changes !

– Offset of beam vs target at 0.05mm level


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



9

CNGS Run in 2008


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


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


12

CNGS Run in 2008


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


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


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


14

CNGS Run in 2008


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


15


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


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




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




19 Filter lifetime - reflectorFilter

exchange

Filter exchange at 1.15E19 pot 4 filter exchanges/y @ (4.5×1019 pot) !




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




21 Horn/reflector cooling system – modifications shutdown 2009

draf

t des

ign


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


22 Layout


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


23


Summary

CNGS water handling


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


CNGS water handling


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)


TARGET inspection


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


27


CNGS target magazine during assembly

TARGET inspection


28 TCC4 inspection – outside the shielding


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


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


Pb screens

CNGS Preparation for 2009


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


LNGS News


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


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


34


cngs issues - that could disturb a smooth operation in 2009 thanks to colleagues who contributed to...

Documents

cngs target

cngs shutdown

outline cngs

cngs duty cycle50

horizontal beam position

cngs lhc md37

cngs design of equipment

beam changes