Si3 PLAN FOR DETECTOR
COMPLETION
(A DISCUSSION
DOCUMENT)
PURDUE GROUP
- The earliest possible date for installation of
Si3 into CLEO/CESR is early February 2000.
- When does Si3 need to be in Ithaca to be ready
for a February installation?
- It takes about one month to assemble Si3 around
the beam-pipe. A further month should be allowed for testing and
debugging by the local team. (discuss)
- Down time over the Holiday Season should be
realistically taken into account (2 weeks?)
- The above three points imply we should aim to
have the detector in Ithaca by Thanksgiving, (allows a month for
testing excluding Holidays) and certainly no later than early
December (allows a month for testing if work through
Holidays)
- Can we complete the detector on this
time-scale?
- The following is our current best estimate of the
schedule for completion of the detector.
- New layer 2 starters arrived safely yesterday,
plan to build replacement for FL208 starting before the weekend.
Once FL208 is mounted and tested we will reconstruct FL202. (This
is the cautious approach). If all goes well the
2nd clamshell
will be complete by the end of October.
- Once
2nd clamshell
is complete it will be shipped to Cornell by Purdue plane. We have
booked the first available date Nov. 11, with a request for an
earlier date if one becomes available. (Other options including
non-Purdue planes etc. could also be explored, comments
please)
- Layer 3 currently has two known problem parts
FL311 and HL324 (in-recovery). There are two ladders to build and
8 ladders to mount.
- If all goes well Layer 3 can be complete as early
as the end of October.
- Since L4's can be installed at Cornell, should
the detector be shipped as soon as L3 is complete? Our view is no,
we believe it is important to gain experience in L4 mounting and
learn if there any problems. Purdue is the best place for that: 3
people with mounting experience, back-up coverage, rapid fixture
modification capabilities etc.
- However if there are L4 problem parts
(stragglers), the optimum scenario for completing the detector is
unlikely to be that all L4's are mounted at Purdue
- We propose as soon as layer 3 mounting is
complete layer 4 mounting will commence.
- If it becomes clear that layer 3 will not be
ready by end of October we propose to commence mounting layer 4,
without waiting to finish layer 3 (this idea should be discussed
again in about a week).
- We are not yet sure how quickly we will be able
to proceed with layer 4 mounting, somewhere between 1 and 2
ladders per day is likely.
- We propose Layer 4 mounting to commence on
November 1, and barring unforeseen problems, mounting at 1 L4
ladder/day è ship December 8, at 2 L4 ladders/day è
ship Thanksgiving week. A date in between these two limits is
likely (December 2)
- Since L4's can be installed at Cornell, once the
supply of layer 4 ladders awaiting mounting at Purdue is
exhausted, we propose the L3/4 assembly will be shipped to Cornell
by plane. We will not wait for L4 stragglers, IN THIS WAY WE CAN
LOCK-IN A DATE NOW!
- The Purdue plane is available on November 24 and
December 2, we have booked the latter date.
- Comments on labor: the above time estimates are
for current staffing levels 4 FTE (mech: Jim and Tom)
(elec: Jik and Jun +IPS), Kirk is away until
11/15
Note: until August we had 9FTE.
- We would still welcome additional help (see
several Sept e-mail requests), but there is little time for
training.