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LAr sLHC Engineering – March 01 st , 2010

LAr sLHC Engineering – March 01 st , 2010. Follow up of the action list. Prepared by Michel RAYMOND. Main comments and new actions (1/2). Opening of the cryostat To study what the cutting off has to be inside the Inner tube, to check the possible conflict with the mandrel (Mircea)

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LAr sLHC Engineering – March 01 st , 2010

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  1. LAr sLHC Engineering – March 01st, 2010 Follow up of the action list Prepared by Michel RAYMOND

  2. Main comments and new actions (1/2) • Opening of the cryostat • To study what the cutting off has to be inside the Inner tube, to check the possible conflict with the mandrel (Mircea) • Spare parts must be foreseen for all parts that may be damaged : seals, Permaglide rails, bolts, rings for welding • Risk analysis to be performed - Need to involve somebody on this task. • Organization of forthcoming engineering meetings • Organization of the meeting is changed • Detector and Engineering meetings are merged (3 hours on Monday afternoon) • One meeting at every LAr week • In between, topical meetings will be organized when necessary. • To identify what topical meeting we can have ? • Is it really suitable to place it in between Lar week ?

  3. Main comments and new actions (2/2) • Super T6 specifications • Super T6 movement can be done thanks to rollers or air pads. The second is mainly suitable if ST6 has to be moved when it is loaded : probably to be avoided. • Some PBS boards will be difficult to access • Detailed specifications required for the interface with the FCal tooling • Mini-FCal insertion tooling • The insertion will be easier if the Cryostat is horizontal. This is a general comment for all Detector extractions and insertions • Load capacity of the Minivans ? They have been calculated for 1.5 ton, but can probably withstand a higher load : to be checked. • FCal Summing board issues • Is there enough spare parts to replace the feedthrough ? Roy will ask Paul what is available and what they can do. • A step by step procedure is needed • Feedback expected by John and Ruben • A topical meeting will be planned, that should address the point of the opening (or not) of the large cold cover. Somebody from the cryostat may be needed.

  4. Follow up of the action list

  5. Follow up of the action list (2)

  6. Follow up of the action list (3)

  7. Reminder (long term actions) • Tilt of the cryostat during the operations : parallel to the beam or horizontal ? • The decision can affect services, cryogenics, Tile calorimeters ( + ?...) • Atlas Movement System can manage this movement to horizontal • Consequences for services or cryogenics to be studied • Is it mandatory to warm up the cryostat in case of MiniFCal installation ? • Not sure if the current warm tube is kept. • The current copper MiniFCal is much lighter than Tungsten one, the current warm tube may be resistant enough indeed. The calculation done on last April will be updated. • The most critical will be the supports of the tube. It is worth to plan a load test using dummy parts. • Drawings of the bearing parts are lost – Research unsuccessful until now • Until serious results the baseline is still to warm up the cryostat • Is a radiation workshop necessary to protect people and environment, • During cutting of the welds ? (dust of material, chips, smoke…) • During the access inside the cryostat ? (Argon contamination) • During welding ? (smoke)

  8. Reminder (long term actions) Cryogenics A second test is foreseen using a different heat power in order to be able to extrapolate the results. A heat of 100 W is suitable, however a proposal from G. Oakham to use the heaters on the inner tube is interesting too. The power is limited to 60 W but it would allow a correlation with simulation. • Engineering coordination • The dose rate calculation will be mainly calculated by RP experts, based on the detailed procedure supplied by the various project engineers. In order to make easier and more consistent the work of the RP experts, it is required to use the template supplied by Fernando to describe the procedures. • For each new equipment, need analysis and technical specification have to be written in order to define a clear basis on which technical options will be discussed. • Neutron moderator • According the information that Roy got from V. Hedberg, the current polyboron material use for the JM shielding will resist up to 1013 n/cm2, but has a clear limit before 1016 n/cm2 • The ageing of this component might be a problem, independent of the decision to install or not a Mini-Fcal. To be discussed with Atlas TC (Michel)

  9. Reminder (long term actions) • HEC wheels extraction • The MPI is not willing to take the responsibility on the HEC wheels extraction and insertion, the MPI’s proposal is to act only as a permanent assistance. This significant operation was previously under LAL responsibility. It has to be covered by the Liquid Argon community. • Experts have to be identified on every sub-system (EMEC, Temperature probes, Purity probes, HV…). The best would be to reproduce the expertise as it was during the integration. • The various actors have to be contacted, probably through the current Lar organization. • It seems really interesting to merge in the same work package the supply of Super T6 and push/pull device. This is to be discussed with our Canadian colleagues : agreed • About details on the procedure and also the way the cables could be arranged, it is agreed that it will be difficult to have reliable results before tests and trials will be done on a mock-up.

  10. Reminder (long term actions) • Feedback on HEC procedure : ALARA oriented • Fernando proposed to use a common template to describe the various process • The first columns have to be fulfilled by the people who are technically in charge of the operation, then RPE will perform the related calculation. • The location of the operator is mandatory in the table, the operator’s position is defined by is body (stomach,…) even if it is not the most exposed part of himself. It is reminded that exposure limits are actually different for hands, feet, etc… But this will intervene (when necessary) in future detailed analysis. • 3 main activities will cause a high level of exposure which are not acceptable actually. • As it is difficult for MPI team to be more accurate in the procedure right now, and regarding that this activity is concentrated in a few days, the optimization of the procedure would not decrease the dose enough. • However, this optimization is part of the process and has to be done carefully. • 1st specification for radiation workshop • This study is starting currently, only preliminary guidelines are given. • If some requirements are not achievable, compensatory measures will have to be implemented • A main difficulty will be to know if there is or not a risk of contamination with Argon • Some requirements seems to be incompatible with some other technical requirements, for instance the tent is supposed to be under pressured when for cleanness reasons we wish to be over pressured • … To be continued

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