Cryostat Status and LHC schedules

1. Cryostat Status and LHC schedules FP420 meeting 19-20 June 2009 K. Potter , D. Swoboda

2. The New Connection CryostatNCC • The conceptual design is complete - only construction drawings remain to be made. • The design has been unofficially accepted by all LHC technical groups, but formal approval needs the NCC to be adopted as a CERN project by the LHCC & Research Board • The manufacture of 4 NCC’s by the CERN Mechanical Engineering group was the subject of a Workpackage document (EDMS 823322) in Feb. 2007 - cost ~ 3 MCHF • The construction schedule and installation schedule have also been studied. K. Potter , D. Swoboda

3. Re: Costs • As explained in the workpackage document 3MCHF covers only the construction costs and does not include all the ‘standard’ LHC components which hopefully can be taken from spares or be provided at no cost by CERN • The manufacturing cost estimate includes a lot of once only ‘tooling-type’ costs which are independent of the number of NCC’s needed. • This led to great confusion in the discussions with the ATLAS referees who were told by the authors of the workpackage that 1 NCC would cost 1.65 MCHF. This is correct and agrees with the 2007 estimate to within 10%, but who wants only one!!! • Hence the cost to experiments ATLAS and CMS depends on them both wanting two NCC’s and requires an agreement with CERN management on the charging policy for LHC components and how to share ‘tooling-type’ costs. (The design was paid by the UK) • I believe there is still hope that the LHC machine can be persuaded to share some costs because the NCC could be used elsewhere in the machine in the future. K. Potter , D. Swoboda

4. Cryostat Design and Manufacturing Effort • Lead time of nearly one year is required before the 1st cryostat can be installed. • No account of delays for procurement of specific components like bus-bars, vacuum sector valves, etc. • The LHC is currently renewing many contracts with suppliers to replenish stocks of spares depleted by the repair. It is a pity we are not yet in a position to ask them to include our requirements K. Potter , D. Swoboda 5

5. Exchange of connection cryostat Time required for cryostat replacement: ~ 5 months • Warm up 1 month • Replace CC ~ 8 weeks • Dismantle interconnect 5 days • Recondition interconnect 5 days • Install new cryostat 5 days • Interconnect cryostat 5 days • Internal leak test before 1 week • El. Test, alignment 5 days • Global leak test, pressure test 3 weeks • Bake out 3 weeks • Cool down 1 month • Cold test 1 week K. Potter , D. Swoboda 6

6. Resources Meeting 27/02/09 organised by Detlef Swoboda Extrapolating from the present status of the NCC design a complement of 18 months is still required to produce the 1st cryostat ready for installation in the LHC machine. In order to ensure timely availability it is mandatory to reserve and where necessary order standard parts (cold feet, B-Bars, etc.). At present orders for spare parts are being prepared. Consequently, it would be strongly recommended to include the components for the 4 NCC in these purchases. This can, however, only be envisaged with the approval of the director of accelerators (S. Myers). The new management has however clearly defined the priorities and guidelines. This results in the necessity for a formal recognition of the AFP/FP420 proposal before any further study involving CERN resources can be expected. My suggestion is therefore to look for at least some official recommendation from ATLAS/CMS. K. Potter , D. Swoboda 7

7. LHC Schedules • Still on official schedule - start-up in Autumn 2009 followed by continuous running at Eb 5 TeV until October 2010. • A shutdown of at least 5 months will then be required • It is then likely that the usual CERN pattern of annual shutdowns starting in December will return • LHC shutdowns are always likely to be at least 5 months • The longer shutdown (6 mnths) needed to install the new Low-beta quads is now end 2013 • Installing 4 NCC’s in the same shutdown requires half the LHC to be warmed up and will require a great deal of manpower and is therefore unlikely. • A phased installation over two or more years is far more likely • A moving beampipe at either 220 m or 420 m (after the NCC is installed) is a two month affair and will still require an annual shutdown but will be less difficult to negotiate as no warm-up is required. • Note that the previous constraint of only warming half the LHC at a time has been removed. K. Potter , D. Swoboda

8. Summary A full design of the new connection cryostat (NCC) which shall replace the present ‘empty’ cryostat has been produced by EN-MME. The design has been validated by the relevant groups in the accelerator department. A final design effort of 6 month is required to produce all manufacturing drawings and get a full approval by the LHC. The manufacturing time for 4 cryostats is estimated to 1 year. Preliminary installation scenarios have been discussed with the LHC transport and installation responsible and an overall cryostat and room temperature beam sector installation plan has been drawn up. The installation and commissioning of the detectors and services does not interfere with the modification of the LHC cryostat and creation of the RT beam sector.  This activity can be planned during scheduled LHC shutdown periods. A considerable amount of cabling between the detector location and the experimental area is needed for the vacuum and beam monitoring instrumentation as well as for the detector services.  This activity could ideally be carried out before the installation of the cryostat K. Potter , D. Swoboda 9