Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12...

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Report dal Technical Coordinator Anna Colaleo

Transcript of Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12...

Page 1: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Report dal Technical Coordinator

Anna Colaleo

Page 2: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Detector Status: gas leak problem

W+ 1, W+2, W-1 : 12 chambers with gas leak replacedW0 one chamber has a serious leak we will try to operate in open mode.

Gas leak tests redone on W0, W+1, W+2 (Claudio Viviani) (in 1.5 months!)

Several connections re-done.2 new chambers with gas leak: RB4 settore 1 W+1 (SISTEMATO provvisoriamente) RB4 settore 8 W+2 (?)

W+ 1, W+2, W-1 : 12 chambers with gas leak replacedW0 one chamber has a serious leak we will try to operate in open mode.

Gas leak tests redone on W0, W+1, W+2 (Claudio Viviani) (in 1.5 months!)

Several connections re-done.2 new chambers with gas leak: RB4 settore 1 W+1 (SISTEMATO provvisoriamente) RB4 settore 8 W+2 (?)

A.ColaleoA.Colaleo

Page 3: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Wheel station   sector leak (ml/h) P(0) mbar P(end) mbar Dt (min) leak(mbar/min)W+2 RB3   S03 400 6 3 19 0.158  RB2 In+out S11 3300 6 3 2 1.500  RB3   S11 >14000       n.a.  RB4   S11 >14000       n.a.                 W+1 RB3   S05 >14000       n.a.  RB1 out S09 >14000       n.a.  RB1 in S10 200 6.5 3.5 39 0.077  RB4 D S10 5300 6.5 1.7 2 2.400  RB2 in S11 >14000       n.a.                 W0 RB1 out S01 350 4.03 3.5 10 0.050  RB3   S02 1400 4 2 8 0.250  RB3   S08 >14000        n.a                 W-1 RB2 in S10 >14000       n.a.  RB3   S10 >14000       n.a.                 

W-2

All chambers ok              

Chambers with problems

System cannot handle the red cases (chamber does not keep any pressure).For the black cases it is possible to compensate the leak with the higher flow.

A.ColaleoA.Colaleo

Page 4: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

To equalize the gas flow between two gaps we use polycarbonate T and L junctions with flow reducers. Tygon tubes connect T and L connectors to the gas inlets.

Gas circuitGas circuit

T and L connectors with Steel 316L Micro-cylinder inside

A

B

C

D

A –L connector B- T connector C- Gas inletD- gap frame

Gas inlet

Gas inlet

Forward Double gap

Backward Double gap

Gas inlet

A.ColaleoA.Colaleo

Page 5: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

W+1We found the following problems:

1) In one chamber we found a broken gas inlet (polycarbonate, glued on chamber) in the gas input circuit of the forward gap. Chamber repaired.

2) In one chamber we found a broken "L" connector (connecting two external pipes) . The connector was in gas input circuit of the backward gap . Chamber repaired.

3) In one chamber we found a broken "L" connector (connecting two external pipes) . The connector was in input circuit of the backward gap . We also found a broken “T” connector in the gas output circuit . Chamber repaired.

4) In the two chambers with small leaks we found that the frame of the gap (polycarbonate glued on the gap) presented a small leak, that we could only localize by the gas sniffer. We could recover the second double gap in both chambers (we keep them as spares).

Page 6: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Polyetilene pipe

CH 47 (W+1 RB1 out/9)CH 47 (W+1 RB1 out/9)

Forward Double gap

Backward Double gap

Service block

Broken "L" connector (connecting tygon and polyetilene pipes). The connector was in gas input circuit of the backward gap . Chamber repaired.

Page 7: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Polyetilene pipe

CH 206 W+1 RB3/5CH 206 W+1 RB3/5

Backward Double gap

Forward Double gap

Service block

A) Broken "L" connector (connecting tygon and polyetilene pipes). The connector was in gas input circuit of the backward gap .

B) Broken “T” connector in the gas output circuit.Chamber repaired. .

A

B

Page 8: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Polyetilene pipe

CH 92 (W+1 RB2 in/11)CH 92 (W+1 RB2 in/11)

One gas inlet (polycarbonate, glued on chamber) in input to the forward gap was broken. Chamber repaired.

Forward Double gap

Backward Double gap

Service block

Page 9: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

CH125 (W+1 RB4-2500/10 ) DG Back GAP UP CH125 (W+1 RB4-2500/10 ) DG Back GAP UP

Backward Double gap

Forward Double gap

Two chambers had a small leak in both cases in the frame of the gap (polycarbonate frame glued on the gap) . The leaks were localized with a gas sniffer.We could recover the second double gap in both cases (we keep them as a spares)

CH 235 (W+1 RB1in/10 ) DG forw GAP UP

Leak here

Service block

Page 10: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

W+2

We found the following problems:

5 chambers with big leaks in the frame of the gap (polycarbonate glued on the gap) always about 20-30 cm from the gas inlet.

One of them presented also gap deformations and broken gas inlet

Page 11: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

CH134 (W+2 RB4-2000/11 left )CH 118 (W+2 RB3/11 left)

CH134 (W+2 RB4-2000/11 left )CH 118 (W+2 RB3/11 left)

Backward Double gap

Forward Double gap

Big leak in the frame of gap Back UP

Page 12: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Backward Double gap

Forward Double gap

CH114 (W+2 RB3/3 left ) CH114 (W+2 RB3/3 left )

Big leak in the frame of Forward GAP UP

Page 13: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

CH 65 (W+2 RB2/3-11 out right )CH 65 (W+2 RB2/3-11 out right )

Backward Double gap

Forward Double gap

Service block

Big leak in the frame of Forward GAP UP

Page 14: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

CH 82 RB2IN left / 11CH 82 RB2IN left / 11

Backward Double gap

Service block

Several problems:1) Found Double gap back deformed and up gap detached from down gap in both sides

15 cm

15 cm

Forward Double gap

Page 15: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

2cm

Page 16: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Backward Double gap

Service block

2) Two big leaks in backward double gap3) Broken gas inlet in forward down gap

One gas inlet (polycarbonate, glued on chamber) in input to the forward gap was broken.

Big leak in the frame of backward up gap

Backward Double gap

Forward Double gap

Big leak in the frame backward down gap

Page 17: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

W-1

We found:

Two chamber with broken “T" connector (connecting two external pipes) . The connectors are in input circuit of the forward gap .

Chamber repaired.

Page 18: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Polyetilene pipe

CH 7 (W-1 RB3)CH 352 (W-1 RB2/3)

CH 7 (W-1 RB3)CH 352 (W-1 RB2/3)

Forward Double gap

Backward Double gap

Service block

Broken “T" connector (connecting tygon and polyetilene pipes). The connector was in gas input circuit of the forward gap . Chambers repaired.

Page 19: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Flow cell readout for W+2 rb3 settore 11

NOTE:Leak tests have been performed in all chambers during construction phase, at ISR, after coupling, before and after installation.

A difference between input flow and output flow in some flow cells in the gas racks was observed already during MTCC. But the instability of calibration of flow cell system in the gas racks prevented us to rely on the flow cell readout. Also the good performances of the chambers during MTCC, local commissioning and Global Runs did not help to discover the problem.

NOTE:Leak tests have been performed in all chambers during construction phase, at ISR, after coupling, before and after installation.

A difference between input flow and output flow in some flow cells in the gas racks was observed already during MTCC. But the instability of calibration of flow cell system in the gas racks prevented us to rely on the flow cell readout. Also the good performances of the chambers during MTCC, local commissioning and Global Runs did not help to discover the problem.

MTCCMTCCsx5sx5 UXCUXC

A.ColaleoA.Colaleo

Input flow

output flow

Page 20: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Planning per l’ISR

•Necessario assemblare le doppie gap buone in modo da avere camere spare pronte

•Sistemare il materiale di recupero (elettronica, capton , meccanica)

•Mettere in ordine l’ISR.

Page 21: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

UXC Hardware BARREL Status W Detect-

tower cables(HV-LV-DCS cables)

LBoxes LinkBoards

LV easy crates

LV modules

RBC Tower cables

MAO

W+2 ok ok ok ok ok ok Ok March

W+1 ok ok ok ok ok ok Ok ok

W0 ok ok ok ok ok ok Ok ok

W-1 ok ok ok ok ok ok ok ok

W-2 ok ok ok ok 50% ok ok March

A.ColaleoA.Colaleo

Missing LV modules and 4 MAO expected in March. Now we move MAO from tower to tower in order complete the commissioning

Page 22: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

W HV cables –patch panel

HV Easy HV distrib.

EASY – majiste SY1527 local cable

HV multicond. Cable test

Trigger cables from UXC-USC

W+2 ok ok ok ok ok ok

W+1 ok ok ok ok ok ok

W0 ok ok ok ok ok ok

W-1 ok ok ok ok ok ok

W-2 ok ok ok ok ok ok

USC55 hardware BARREL Status

HV modules not all in place! We move from one easy crates to the other in order to test the chambers. All modules will be at CERN in March

A.ColaleoA.Colaleo

Page 23: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Example: WB+1

RPC cables in all Wheels have bad path because the connector in MAO is in opposite side with respect to the power distribution box . Solution: remake the cabling passing the cable under the rack.Material ordered.

Front side Back side

Tower Cabling for MAO and EASY CRATES

Ricablaggio sulle torri e sistemazione dei cavi di HV in S1 entro Marzo (tecnici Napoli)

Page 24: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Link system installation

Maciek Kudla, CERN, CMS week, CMS Joint RPC/Trigger Meeting 27.02.2008 24

•YB+2,+1, 0 - commissioned from USC;•YB-1,-2 - all LBBs with boards installed, all cabled;•YB-1 - commissioned now;•YB-2 - to be commissioned;

•YE+3,+1 - LBBs installed and cabled, no boards installed;•YE-1,-3 - LBBs installed, no boards installed, cabling started:

• YE-3 to YE-1 mini chain cabling done,• LBB LV cabling done,• Control, Trigger, TTC cabling to be made.

Enough modules for barrel and endcap installation, BUT lack of spare modules - need to fix broken modules or small production!

Page 25: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Trigger installation (1)

Maciek Kudla, CERN, CMS week, CMS Joint RPC/Trigger Meeting 27.02.2008

252525

• UX-US cables (YE+3,+1,YB+2,+1, 0, YB-1,-2) installed;• UX-US cables (YE-1,-3) - waiting for installation;• USC trigger cabling -

• TTC, GMT, DCs, Slink cables - done;

• TC(11), TC(9), TC(1) - installed and cabled,

• TC(10), TC(2), TC(0) - will be installed without TBs this week,

• the rest of TCs and TBs will be installed in April,

• DCC cables (TBs to DCC_PP and DCC_PP to DCCs) - installed,

• Splitter cables delivered CERN, cabling in April;

Fully cabled TC

Page 26: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Trigger installation (2)

Maciek Kudla, CERN, CMS week, CMS Joint RPC/Trigger Meeting 27.02.2008 26

• Trigger Boards (TB):• 17 installed in USC;

• 105 delivered to Warsaw + 5 waits for missing components in factory),

• 8 - tested,

• 69 – ready to be tested,

• 16 optics to be installed in UW lab;

• last 7 will be delivered to Warsaw this week;

• mid of April - delivery of TBs to CERN.

• Trigger Crates (TC):• 3 - installed now in USC,

• 3 - will be installed in USC during this week;

• one TC send to Wiener to be repaired;

• the last 6 will be installed and cabled in USC staring mid of April.

Page 27: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Tower Test

• Detector performance procedure, using the final RPC-Trigger system:

1) Connectivity Test Strip Connectivity Test – dead strips FEB – LB Connectivity Test – swapped cables Noisy FEB

2) Threshold Scan Noise rate as a function of HV and threshold.

4/ 5 Wheel tested. W-2 to be tested next week

A.DimitrovA.Dimitrov

Page 28: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

RPC Technical Trigger Status

• Installation of RBC boards on the detector towers: done

• Cabling of negative wheels: this week

• Installation of TTU boards in USC55: 1 out of 3 (can cover up to 2 wheels)

• The installation will be completed as soon as full production of Trigger Boards (Warsaw) will be delivered

• TTU is under testing BUT:

• always in conflict with RPC Trigger activities and Tower test

• since July 2007, TTU could use the system for few days only

• DCC problems prevent to validate the implemented algorithms

We succeeded to take data yesterday evening. Data are been analyzing

F. LoddoF. Loddo

Page 29: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

To be done:

• Validate the implemented algorithm using any readout

1. At sector level

2. Tower level

3. Wheel level

• Study the timing calibration for cosmic muons

• Xcheck with DT trigger

• Coupling with Global Trigger

• Provide Trigger for any cosmic run, May Global Run and CMS startup

F. LoddoF. Loddo

Need automatic data analysis and DQM ready (at the moment only 2-3 people can see the data)

Page 30: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Awaiting full commissioning

Readiness of final UXC RPC gas system Installation and connection of end cap Link Boards Borrow AC/DC, HV, LV PS from barrel (CAEN delivery late) Finalize missing cables (power and DCS) inter racks and crates Finalize connectors on HV umbilical cables in USC Control PC Manpower Other tasks: HV distribution boxes Assembly, test and installation of 6 high eta RE1/1 (see S.Park) Finalize the FW specific software

FIRST COMPLETE BARREL COMMISSIONING

In sequence : 60 degree sector on YE+1 (i.e. 6 RE1/2 & 6 RE1/3) then rotate

60 degree sector on + end cap (i.e. 36 RPC on YE+1 & YE+3)

Prerequisites :

Page 31: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

W HV testUXC-USC

LV , DCS test Tower test RBC-TTU(cosmic test)

Access to the wheel

W+2 ok ok ok April

W+1 ok ok ok March no

W0 ok ok ok March + no- No from 7 march

W-1 ok ok ok April No from 14 march

W-2 ok March March May

Commissioning status and plan

We are using the final LV power system from S4 on W+2, W+1, W0, W-1

A.ColaleoA.Colaleo

Page 32: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Local commissioning

Item /responsabilie

Minidaq (Cimmino)

TTU test (Baesso)

Tower test(forward )

chamber monitor (viviani)

Equal. flow cell

Gas system setup

mese

W0 100% fill mode

50% run mode

Marzo

aprile

W+1 Temporary sys

100% fill mode

50% run mode

Marzo

Aprile

Maggio

W+2 100% fill mode50% run mode

AprileMaggio

W-1 100% fill mode50% run mode

Aprile Maggio

W-2 Temporary sys100% fill mode50% run mode

MarzoMaggioGiugno

Necessari turni su questi item : fornite per favore la vostra disponibilita’

Essendo legati alle trigger board installate possiamo iniziare con i 4 settori delle torri near (settori 2-3-10-11). Studio efficienze, correnti, cluster size, noise rate, noise profile con TTU trigger .

Page 33: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Schedule for completion - update Schedule for completion - update StatusSupplier: okMixer: okHumidifier: okPurifiers: commissioned, at the moment not in use Pre-distribution and pump: okFinal distribution: ok (back-up system to be adjusted)

Pressure Transmitter on the detector: only negative Endcap missing

StatusSupplier: okMixer: okHumidifier: okPurifiers: commissioned, at the moment not in use Pre-distribution and pump: okFinal distribution: ok (back-up system to be adjusted)

Pressure Transmitter on the detector: only negative Endcap missing

Commissioning statusPositive end (W0 included) completely commissioned. Final distributors connected to the final system. Some fine tuning has to be done on the back-up and purge lines.

Infrared analyzer installed and operationalThen we are ready to use the final mixture.

Commissioning statusPositive end (W0 included) completely commissioned. Final distributors connected to the final system. Some fine tuning has to be done on the back-up and purge lines.

Infrared analyzer installed and operationalThen we are ready to use the final mixture.

R. GuidaR. Guida

Page 34: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

A new ELOG entry has been submitted:

Logbook : RPCAuthor : Roberto GUIDA , mailto:[email protected] : OtherSubject : CMS-RPC YB+2 under gas with final gas system

Logbook URL : https://cmsdaq.cern.ch/elog/RPC/671

=================================

Dear all,

all the RPC on YB+2 are connected to the final gas system since yesterday late afternoon.The system is in fill mode and the total flow from the mixer is about 450 l/h.Mixture composition (R134a 96.2%, iC4H10 3.5 %, SF6 0.3 %).Humidifier On, but not stable.Exhaust module forced in run mode with YIC5003 forced closed (in order to use also the MFC).

The pressure in the chambers is:rack 78 (YB+2 top part) +0.2 mbarrack 73 (YB+2 bottom part) +0.2 mbar

Alarm for chamber pressure are HH 0.7 mbar, LL -0.7 mbar.

Cheers,

Mar, Andrea, Roberto

Status

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Page 35: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

RPCs on final gas system:4 sectors on W0 will be connected to the final gas system .These sectors will operate in fill mode (i.e. open mode) for at least one month in order to verify the RPCs performance :- noise rate and noise profile (every 2 hours) -Efficiency -Currents and working point take data continuously

During that test also the performance of the Purifier modules will be checked working with the exhausted mixture.Once we will be confident with the system (gas mixture, humidity stability and purifier performance) we will switch to run mode (closed loop mode) with some high percentage of fresh gas (starting from ~50%). Same procedures for data taking

RPCs on final gas system:4 sectors on W0 will be connected to the final gas system .These sectors will operate in fill mode (i.e. open mode) for at least one month in order to verify the RPCs performance :- noise rate and noise profile (every 2 hours) -Efficiency -Currents and working point take data continuously

During that test also the performance of the Purifier modules will be checked working with the exhausted mixture.Once we will be confident with the system (gas mixture, humidity stability and purifier performance) we will switch to run mode (closed loop mode) with some high percentage of fresh gas (starting from ~50%). Same procedures for data taking

Gas parameter monitoring in DCSWe are preparing the software in order to have all the information about the gas system in the RPC-DCS together with the information about the detector performances. For the moment we are reading the gas parameter from the PVSS of the gas system (Claudio, Roberto, Giovanni)

DSS interlock to the detector high voltage in case of gas system stop.It is foreseen an hardware signal generated in each gas control rack in case of problem with the gas system. This signal has to be configured and connected to the CMS-RPC high voltage system. Most probably it will be ready in one month

Page 36: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Pending problems:Flow-cells issue. In the final distribution, the supply and the return flow per each channel is read-out by means of flow-cells. The flow measurement was expected with a precision at the level of few %, while we have some channels with input-output difference at the level of 30 %.

We are trying to evaluate the problem (we just finished the commissioning of the positive end).

One example:

In order to start we will adjust the reading taking into account the measured difference.

Pending problems:Flow-cells issue. In the final distribution, the supply and the return flow per each channel is read-out by means of flow-cells. The flow measurement was expected with a precision at the level of few %, while we have some channels with input-output difference at the level of 30 %.

We are trying to evaluate the problem (we just finished the commissioning of the positive end).

One example:

In order to start we will adjust the reading taking into account the measured difference.

R. GuidaR. Guida

Page 37: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

From the end of 2006 a dedicated test has been set-up for the re-circulation study

However, many problems appear:

1. pump failure (Jan07)

2. Bad quality of the R134a cylinders after a change in the supplier (Mar-Sept07)All the R134a cylinders analyzed since June 07 with the Gas Chromatograph:

6 cylinders < 500 ppm vol “air” 3 cylinders ~ 4000 ppm vol “air”4 cylinders >> 30000 ppm vol “air” (plus unknown component/s)

Since September all the cylinders arrive with an “air” concentration < 1000 ppm

3. Saturation of the purifiers followed by more than one month of operation in open mode in order to recover the detectors (Nov07-Jan08)

4. Abnormal amount of air in the closed loop after the Christmas shutdown (Jan-Feb08). Found several weak points due to old o-ring. The problem has been fixed last week.

5. New closed loop cycle started on 25/2/2008

From the end of 2006 a dedicated test has been set-up for the re-circulation study

However, many problems appear:

1. pump failure (Jan07)

2. Bad quality of the R134a cylinders after a change in the supplier (Mar-Sept07)All the R134a cylinders analyzed since June 07 with the Gas Chromatograph:

6 cylinders < 500 ppm vol “air” 3 cylinders ~ 4000 ppm vol “air”4 cylinders >> 30000 ppm vol “air” (plus unknown component/s)

Since September all the cylinders arrive with an “air” concentration < 1000 ppm

3. Saturation of the purifiers followed by more than one month of operation in open mode in order to recover the detectors (Nov07-Jan08)

4. Abnormal amount of air in the closed loop after the Christmas shutdown (Jan-Feb08). Found several weak points due to old o-ring. The problem has been fixed last week.

5. New closed loop cycle started on 25/2/2008

Closed loop at ISR: historyClosed loop at ISR: historyR. GuidaR. Guida

Page 38: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Master Planning for closed loop ISR• 25/2 Closed Loop running with saturated filters• 3/3 Currents start increasing

– stop CL– regenerate filters, take samples of used filters– restart CL,– check air-tightness of 3 gas gain monitoring gaps, connect 3 gas gain

monitoring gaps to closed loop• 24/3 Currents start increasing

– stop CL– take samples of used filters, install new filters,– install sampling flasks, install F- specific electrodes– restart CL, start gas sampling

• 15/4 Currents start increasing– Stop CL– Take samples of used filters, regenerate filters, resume sampling

• May – Start Gas and filters sampling with individual purifiers

R. Guida-S.BiancoR. Guida-S.Bianco

We are already not on schedule and this plan does not take in account the chamber recovering time

3 cyc

les in

2 m

onth

s?

Page 39: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

USC5UXC5

C2H

2F 4

/SF 6

/i-

C4H

10 /

H2O

Slow CtrlGC, p/T/RH/Ph

CMS

VENT

PU

RIF

IER

S

SGX Bldg

RPC TRIG2RPC TRIG1

RPC TRIG4RPC TRIG3

RPC PAD REF2RPC PAD REF1

RPC PAD MON6RPC PAD MON5

REFERENCE half wheel lines

VENT

VENT

RPC PAD MON4

RPC PAD MON3RPC PAD MON2RPC PAD MON1MONITOR

VENT

Gas Gain Monitor (conceptual design)

VENT

S. BiancoS. Bianco

Page 40: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Gas Gain Monitoring System tests

• System operational at ISR, working on integration with DCS

• Tests on sensitivity of charge and avalanche/streamer ratios for working point changes

• Good sensitivity in avalanche-to-streamer transition regions

• Run with (0% SF6) --> (0.3% SF6) last week, analysing results

Time schedules for the tests ?

S. BiancoS. Bianco

Page 41: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Equipment management database

All elements (chambers, racks, Easy crates, modules etc) must be integrated in the official CMS database (CMS labels, bar code).

Construction database must include references to all internal elements (ex. FEB, Control boards) .Need to update the information as soon as possible.

Construction databases must be: either

1) Linked to the CMS official database (Stephane Bally) and we have to guarantee the maintenance of it for CMS like (RPC responsible for that)

Or

2) integrated in the CMS database (no need to maintain in the future).

Need to take a decision about those possible solutions. RPC responsibles for the construction database should contact Stephane Bally in order to implement one of this solution.

Page 42: Report dal Technical Coordinator Anna Colaleo. Detector Status: gas leak problem W+ 1, W+2, W-1 : 12 chambers with gas leak replaced W0 one chamber has.

Conclusions and comments• Barrel installation almost completed and local commissioning ongoing: since May07 4/5 wheels commissioned

• Final gas system ready in PT5, but we have to work only with safe procedures (DCS, DSS).

• We can start new commissioning phase to check the chamber performance with TTU trigger . TTU trigger not fully operational since readout problems prevent to validate the implemented algorithms : first good data took 10 days ago. Intensive program to fully validate the system in next 10 days maximum.

Need automatic data analysis and DQM ready (at the moment only 2-3 people can see the data).

• We have to define the standard operation procedure and start to apply them in order to be ready for data taking during Global Run.

• ISR and GIF tests for the closed loop system: need realistic schedule