From settles@mppmu.mpg.de Thu Jan 18 12:13:24 2007 Date: Thu, 18 Jan 2007 12:11:08 +0100 (CET) From: Ronald Dean Settles To: LC-TPC@desy.de Cc: LCTPC CB/TB combined list -- 'Keisuke FUJII' , A.F.Buzulutskov@inp.nsk.su, alexander.kaukher@desy.de, Anatoliy Krivchitch , Ariane Frey , bamberg@physik.uni-freiburg.de, Dan Peterson , David Nygren , Dean Karlen , desch@physik.uni-bonn.de, Harry van der Graaf , henning.schroeder@physik.uni-rostock.de, Ivor Fleck , jan.timmermans@nikhef.nl, Joachim.Mnich@cern.ch, jpmartin@lps.umontreal.ca, Leif Jonsson , lepeltier@lal.in2p3.fr, Luciano.Musa@cern.ch, Lucie.Linssen@cern.ch, Madhu Dixit , Michael.Hauschild@cern.ch, Paul.Colas@cea.fr, Peter Schade , Peter Wienemann , rickv@fnal.gov, sawyer@phys.latech.edu, Stefan.Roth , Sugiyama Akira , Takeshi Matsuda , ties.behnke@desy.de, Y Gao , rolf-dieter.heuer@desy.de Subject: Summary of WP#2 Discussion 16/01/2007 Dear friends, As you know, we had an electronics meeting on Tuesday. So that everyone knows what's going on, here is the info and Leif's summary of the meeting... Best greetings, Ron Summary WP#2 Discussion 16/01/2007 -------------------------------------------- Present: --David Attie --Paul Colas --Klaus Dehmelt --Klaus Desch --Madhu Dixit --Leif Joensson+Lund group members --Alexander Kaukher --Jean-Pierre Martin --Takeshi Matsuda --Luciano Musa --Dan Peterson --Oliver Schaefer --Ron Settles --Akira Sugiyama ...anyone forgotten? Agenda and Summary: -------------------- 1. Discussion on the evolution in number electronic channels for LP1. For reference: -Leif's overview at the October Eudet meeting in Munich: http://mppmu.mpg.de/~settles/tpc/lp/wpmtg/leifeudetmpi.pdf -A note sent by Leif on options for the DAQ: http://mppmu.mpg.de/~settles/tpc/lp/wpmtg/tpclpwp2_eth.pdf -Luciano's LP/LCTPC electronics report to the WP#16 on Dec.6: http://mppmu.mpg.de/~settles/tpc/lp/wpmtg/wpmtg16summary06122006r.txt 2. Leif's summary of the discussion: Dear friends, I will not try to summarize the partly quite involved discussion during our meeting but rather try to write down the tasks which were distributed. The ALICE r/o electronics: The big advantage with this system compared to other ideas is that it has gone through a careful development phase and has been extensively tested with respect to its performance. For the EUDET project this is the system, which we at this moment can expect to have ready and working till the end of 2007. The ongoing development concerns a new charge amplifier, which exists in its first version. The tests of this have shown a performance better than specifications. The second version will be submitted soon and will be available for tests in the summer. The ALTRO chip exists in its 40 MHz version in a number sufficient to equip about 2000 channels. For additional channels we have to decide as soon as possible if we need 40 MHz, which would be quite expensive, or if we can do with 25 MHz, which is a cheaper choice and the sampling rate should be enough.. One possible problem is that the physical dimension of the boards does not match the smallest pad dimensions that we want to consider. This means that we in any case can not connect the boards directly to the end-plate but have to use cables with a maximum length allowed by the noise level. For 16 boards (corresponding to about 2000 channels) we assume that this will be ok but for the around 80 boards which are necessary for 10.000 channels it is less obvious that there will be no problems. If it turns out that there is a solution to this problem, then the boards have to be redesigned only with respect to the smaller connectors we have to use. However, if we find that the cable lengths become unreasonably long then we have to consider a complete redesign of the board. DECISIONS: 1) Lund will make drawings for a couple of scenarios to get a more firm estimate of the cable lengths we are talking about. 2) Everybody should keep their eyes open for suitable cables, which are compatible with 0.5 mm pitch, have a high degree of flexibility in all directions and have a capacitance that is compatible with that of the preamplifier. 3) CERN should send the pin assignment for the new preamp to Lund as soon as possible, so that the redesign of the board can start in order to accommodate the new connectors. Other options: Jean-Pierre and Mahdu announced the recent development of an alternative, which at some stage may include the new preamp developed at CERN but for the rest is based on commercial components. To my understanding the first version is ready for tests. DECISION: Information on this system should be distributed to all the participants by Jean-Pierre and Mahdu Additional read-out systems were mentioned but not discussed in detail. The DAQ system: With only 2000 channels it would be straight forward to use the U2F card and a USB interface as was done for the tests of the ALICE electronics. For a significantly larger amount of channels this is not an ideal system. Luciano proposed instead to use the DAQ system, which has been developed for the ALICE experiment. This system requires a common back-plane, which would not meet the flexibility requirements we have, and would therefore need a redesign. There is another alternative, which has been mentioned by the Lund group and is based on read-out with Ethernet, where the boards are read out independently. Since it turned out that not everyone had seen this note, it can be gotten from the above website DECISION: Luciano should provide the link to the web site where we can learn more about the ALICE DAQ system. It was finally decided to have the next meeting on the read-out electronics on the 31st of January. During that meeting we should also prepare for a more detailed discussion on the DAQ system.