Dear James, Neville and Phil,
I am writing to you in your roles as heads of various PPARC committees
to alert you to the existence of a group which has just formed to look
into electromagnetic calorimeter (ECAL)studies for a future linear
collider (LC). The LC is, of course, already on the PPARC Roadmap so 
the important physics case is well known. Also, there is already UK
involvement in other aspects of the detector, most notably the LCFI
group. This new ECAL group has joined the already-existing effort within
the UK.

The possibility of this new effort was first raised earlier this year and
indeed a statement that there may be some UK interest interest in this was
flagged in the "Blair Report". Over the summer, we have been forming a
group and making contact with the effort going on in other countries in 
this area. This came together only following the Krakow LC meeting in 
September, which unfortunately was too late to allow us submit a SoI
to the last PPRP meeting. Hence, we thought it would be sensible to
let you know what is going on directly.

The work in this area within Europe has been led mainly by Jean-Claude 
Brient at Ecole Polytechnique in Paris and it is called the CALICE 
collaboration. More information on this can be found at
    http://polywww.in2p3.fr/tesla/calice.html
There are some other European institutes interested in the ECAL who are
working outside the CALICE group but the latter is clearly considered to
be the baseline effort from the TESLA perspective. The CALICE collaboration
proposes a silicon-tungsten ECAL. This widely accepted to be the best 
solution for physics as it can in principle deliver the excellent energy
and position resolution which are essential for many physics studies at a LC.

However, it is not at all obvious how such a detector can be constructed.
The technology of the silicon diode detectors themselves is relatively
well-understood. However, the main problem will be integration of the
mechanical structure, the silicon diodes and the readout electronics without
seriously compromising the ECAL performance. These issues can be best
tackled by building a prototype and this is exactly what the CALICE 
collaboration proposes to do. The timescale is to construct this prototype
and put it in a test beam by late 2003 or early 2004. The UK group would
like to get involved in this work and so this date sets the schedule.

The collaboration submitted a proposal to the DESY PRC (PRC R&D 01/02)
earlier this year and have sent an update to the upcoming October PRC
meeting. Both these documents are available from the above web site, under
the official documents link. The UK groups were able to add a section
about their intention to become involved as part of this update. This 
section was, of course, strongly qualified by statements that we requiring
UK funding to proceed and that this was not in place. The list of UK people
who signed the PRC update is given below.

In order to take this further, we will therefore need to obtain funding
through PPARC within the next half year. We realise the financial situation
is difficult right now and we are under no illusions that this will be easy.
We need to think carefully about how much we could commit to providing for
the collaboration so as to match the likely resources (of money and effort)
available. We would therefore be grateful for any advice which you could
give us. Many thanks,
                              Paul Dauncey
                               for the UK CALICE group


Birmingham: C.M.Hawkes, S.J.Hillier and N.K.Watson
Cambridge: D.R.Ward and M.A.Thomson
Imperial College: P.D.Dauncey
Manchester: R.J.Barlow, I.P.Duerdoth, N.M.Malden and R.J.Thompson
UCL: H.Araujo, J.M.Butterworth, D.J.Miller, M.Postranecky and M.Warren