UK-CMS ECAL Meeting - RAL 1 April 1998 - Summary minutes
Present:
G.Heath, H.Heath, A.Presland, V.Smith, R.Tapper (Bristol), D.Imrie (Brunel), G.Barber, D.Britton, G.Davies (ICSTM), H.Ali, K.Bell, R.Brown, D.Cockerill, J.Connolly, L.Denton, P.Jeffreys, B.Kennedy, T.Lodge, G.Patrick, M.Torbet, B.Smith, R.Stephenson (RAL)
RMB gave details of the deliverables written into the MoU. The costings are based on "pure guesses". Several items ahave had to be excluded:
The total UK financial commitment for deliverables was £1102k, under the assumption that we would provide 50% of the alveolars.
The financial breakdown of the endcap project is given in the MoU as follows, based on the guesstimates in Cost Book 9.
| Regional Centre | 400kSf |
| VPTs | 950kSf |
| Mechanics | 800kSf |
| Assembly/installation | 550kSf |
| Total | 2700kSf |
A realistic justification of this figure is:
| Deliverables (w/o alveolars) | £952k |
| R Centre/tooling | £203k |
| Total | £1155k (= 2.68MSf @ 2.32Sf/£) |
Thus, the deliverables saturate the 2.7MSf from the MoU, without allowing for Regional Centre manpower.
With inflation, this £1155k becomes £1250k in "£ of the year". This is to be compared with the £1303k which is available for construction, not counting hired manpower (£1218k), and allowing £100k for prototyping.
RMB summarised the 1998/99 allocation for CMS.
Requsition:
| Common Fund | £148k |
| Tracker | £209k |
| ECAL | £123k |
| Total | £480k |
1998/99 requisition bid
Travel:
DB mentioned some apparent discrepancies between FAMIS and his own estimate for IC travel - the figure of £116.71k may increase by £5-6k because of this.
Quadrant model should be ready for RAL open day (1 June). ICSTM agreed to supply 5 supercrystals and support plates/spacers for this date. Some assistance from RAL in measuring spacers would be useful. LD will fix the SCs, spacers etc to the (already existing) back plate.
BS summarised the status of the minisupercrystal:
Attempts to fit the 9 crystals into the 3x3 alveolar have shown that both crystals and alveolar are outside their spec, and the crystals therefore do not fit properly. Crystal lengths range from 219-221mm - none being close to 220mm. Most are too large in the front dimension (spec is 23.7 ± 0.1mm). At the rear, only 1 is within the tolerance (24.9-25.0mm). Agreed that gauges will be needed during production for fast rejection of outsize crystals.
GH described the state of production in Bristol. Richard Head will be away for some time - in his absence, Vince Smith is the contact person. Production of spacer plates and front stops is in progress and on schedule. If necessary, existing plastic front stops could be used if the new ones were delayed.
DCI reported the status of VPT testing.
VPTs in hand:
Results shown at 0 field (all ET and Hamamatsu) and 400mT (sample of ET and Hamamatsu). For all tubes, best results with 600-800V on anode, and dynode at 100V less than anode. Typically, gain at 400mT about 20% less than that at 0 field. Excess noise factors in range 1.5-2.
DCI will endeavour to test ET tubes at B=0 at Brunel before Easter, and RIE after Easter. Best 9 should then be tested at high B (at RAL). Some discussion of screening VPTs - decided to apply screening foil to all VPTs for the 3x3 tests; JFC requested tubes 1 week earlier than previous plan to allow for this work. For endcap production, JFC estimated 2.5 person-years to screen all VPTs.
MT described the electronics design for the miniSC. Because of the limited space on the miniSC, the electronics assembly has been moved outside the backplate, with only a patch panel inside. Should be ready by 24 April. Frank Jacob will provide the low-voltage power supply.
GB showed the current design - to be finalised by 3 April. A copper cooling plate will be needed to fit onto the back plate. Space must be left at the front of the SC for the 2cm+ ferrules and the fibre beding radius for the blue LEDs.
KWB reported on bahalf of Frank Jacob:
DJAC has LED + electronics + fibres. Vasily Katchanov will fax instructions for powering system. At least 2cm of space must be available at the front of the supercrystal to allow for mounting and the bending radius of the fibres.
GD reported on a meeting at Saclay 30/3/98.
Saclay expect to provide (by 20 April):
After discussion, agreed that 50cm fibres are too short; GD will ask them to supply longer (1m?) fibres instead. Saclay system should go inside the box. Will ask Saclay to make 2 shaping amps, rather than 1.
For the beam tests, the red laser cannot be triggered independently by H2 and H4, so if both beams run in parallel only one can trigger, while the other is a passive receiver of laser pulses.
KWB set out a testing scheme for the 3x3 miniSC before and during assembly:
1. Components:
2. Assembly Phase:
DB reported results from IC on simulation of light collection. His conclusions were:
Decision: no grinding or reflector for first H2 cycle. (Nb: H2 ends July 15, H4 available Aug 12-31).
DB also raised the problem of pinholes in the alveolar walls - this could lead to optical cross-talk in the absence of wrapping.
Everything should be ready to start assembly by 20 April. The assembled minisupercrystal will go to CERN on 18 May. The Saclay laser should also be installed at CERN on 18 May.
After some discussion, it was decided that the assembled minisupercrystal, demounted from the back plate, would be robust enough for careful road transport to CERN.
The next meeting was proposed for 6 May 10.30-17.30, at RAL. DJAC will circulate details later.
Minutes: B W Kennedy, 6 April 1998