Summary of 7th WP meeting 16/08/2006
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Wednesday 16 August
West Coast East Coast W.Europe Japan
07.00 10.00 16.00 23.00
Present:
Klaus Desch
Madhu Dixit
Michael Hauschild
Katsumasa Ikematsu
Leif Jonsson
Alexander Kaukher
Dean Karlen
Martin Killenberg
Dan Peterson
Peter Schade
Oliver Schaefer
Ron Settles
Akira Sugiyama
Jan Timmermans
Michael Weber
AGENDA
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See the agendafoils
http://www.mppmu.mpg.de/~settles/tpc/lp/wpmtg/wp7thmeeting16august2006r.ppt
-1.News
-Formation of the LCTPC/LP Collaboration
-WWS-R&D-panel tracking review at Beijing
-2.WP meeting
-LCTPC/LP goals (Ron)
-LP electronics connectors (Leif)
-LP endplate (Dan)
-3.Future meetings
-4.AOB
1. News
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1a. Status of the LCTPC/LP collaboration (foils#3-4)
The names for Collaboration-Board (CB) representatives from three more
groups have been identified (one at this phonemeeting); very few are
missing (the non-checked groups on foil#4). RS will send around the
CB list to everybody this week, and the next round of discussion on the
organization of the collaboration between the spokespersons, technical
board and collaboration board can start.
1b. WWS-R&D-panel tracking review at Beijing (foil#5).
As announced at the VLSW06, the WWS-R&D Panel is starting regular reviews
of the different R&D projects for the LC detector at the regional
meetings. Chris Damerell has sent an announcement but it has not yet
been approved by the WWSOC since there are several open questions about
the procedure (therefore the mail cannot yet be circulated). The idea is
to start by reviewing tracking (TPC and Silicon) at Beijing, then other
subsystems at subsequent workshops. We would have to update the report
every 4/3 years if this procedure is adopted.
2. WP Meeting
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2a.Purpose of the LP/SP (RS) (foil#6)
A short update to the rather lengthy discussion last week: gating with Gem
is something we should test first with small prototypes before it can be
implemented on a LP endplate. Exchanges of ideas on how to do this
a.s.a.p. have started (Fabio Sauli, Akira Sugiyama, Martin Killenberg,
RS); anyone interested is invited to join (send RS an email).
2b.More on the LP electronics (Leif)(foil#7)
Leif sent around a note on the connectors that was written following the
January Amsterdam meeting on Eudet tracking:
http://mppmu.mpg.de/~settles/tpc/lp/wpmtg/lpconnectorarr.pdf
The connectors+frontend boards match (via a multilayer board)
a padsize of 1mmx4mm and can be adapted to any pad geometry via flexible
cables or pins between pad and connectors. In the note, several options are
described (miniFEC, dualminiFEC, midiFEC). Leif said there had
thinking as to whether the preamp/shaper should be integrated with or
separated from the ALTRO digitizer; after the discussion at the 02082006 WP
meeting, where a different philosophy for the preamp/shaper was proposed,
it may be better to separate the two. Madhu asked about the number of bits in
Altro; Leif replied 8.5 bits at 40MHz and 10 bits at 25MHz. There was a
discussion about the padsize, padpitch; the alternatives are 1) to keep
the pitch the same in all padrows and have raged edges at the end of a
panel/sector or 2) to change the pitch slightly from row to row so that
pads line up at the edge of a panel/sector. Opinions were divided so that
no final conclusion was drawn and the debate will continue next
meeting(s).
2c.LP endplate (Dan)(foils#8,9,10)
Dan showed the latest iteration which includes connectors on a panels:
http://w4.lns.cornell.edu/~dpp/linear_collider/LargePrototype.html
(second row shows connector details.)
Several details were discussed; here is Dan?s description of the
alternatives:
In one basic configuration, there must be an intermediate
signal path from the "pad board" on the inside of the chamber to
the "connector board" on the outside of the chamber. This is
the configuration that Dan shows in the drawing available on the link.
Ron envisions many small coax cables soldered between the
boards; Dan envisions a "bed-of-nails"; Leif at the end of his note (2b above)
mentions possibility of a kapton flexible-circuit. But these are details.
In these ideas, the setup is more complicated since an extra layer
is needed to hold the connectors. This configuration has
the benefit that it allows for the heat-isolating air space between
the boards.
In the other basic configuration, the connectors are mounted
directly onto the pad board. The pad-to-connector paths are contained
in a multi-layer board. This is what Leif is describes in the note above (2c).
This is mechanically simpler, but there is no straightforward
way to provide the heat-isolating air space.
(Note by added RS:The cooling will be a major issue for the LCTPC -
though not so critical for the LP - so we should be thinking about it now.
The flexible cables or bed of nails to provide the space for blowing
air between the pads and preamps is an important feature. Since a sandwich
structure is the logical solution for providing adequate stiffness to the endplate,
the pads would be on the outside of one layer of the sandwich and the connectors on
the outside of the second layer. Inside the sandwich structure would be the cable or
nails. The cable or nail will provide more length for the temperature drop
and will be cooled directly by the forced air. Putting the connector/preamps directly
on the pad plane would make it more difficult to prevent the preamp-heat
from being conducted into the TPC volume since the distance between the
heat source and the pad would be shorter (less length for the heat drop) and
the traces less accessible to the cooling.)
Due to 1h time limit for our phonemeeting, the
discussion had to be stopped and will also be continued next time.
4. Future meetings (foil#11)
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-The next phonemeeting will be in two weeks, on the 30th of August.
-Paul/Akira are organizing the 'endcap meeting' in Paris 12-15 September;
first details have been sent to everybody. Reservation of hotel rooms
will be explained in more detail soon.
-The annual Eudet meeting will be in Munich 18-20 October,
-the European LC workshop in Valencia 6-10 November, and
-the Asan LC workshop in Beijing 4-7 February 2007.
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