Summary of the UK HARP Meeting held on Tuesday 6th June 2000 in Oxford

Present: Giles Barr, Chris Booth, Craig Buttar, Rob Edgecock, Alan Holmes, Richard Nicholson, Paul Soler.

Minutes of meeting of 2nd May 2000: - accepted without modification.
Actions from previous meeting:

GB Visit Mario Scandurra while at May CERN HARP meeting to get diagrams - Done.
RE Bar-code reader -- These cost about 200 GBP from RS components. Sticky labels with sequential code numbers can also be obtained cheaply. Rob will talk with Jaap to see what type is required. ACTION: RE
AH & RN Discuss tube-endcap fittings - Not done yet. ACTION AH & RN
GB Discuss larger hole in TPC flange at CERN - Done, in fact, this had already been requested and changed by V.Palladino. Annoyingly, this change was not transmitted to us !
RN Consider support possibilities for thick targets - Best method seems to be to have a tube like the thin targets which extends along the upstream half and supports target in centre, with an additional contact near the upstream end to hold it horizontal.
RN Think about fishing wire solution for target retention - Abandoned - difficult to avoid sharp bending radius of fishing wire.
AH Think about Li, Hg, K2K and miniBoone target supports.
GB Arrange direct contact with miniBoone and K2K people for target supports - It was agreed with V.Palladino that this should be done, however, we have not yet established the connections ACTION: GB

Drawing updates: It was desired to have access to CERN drawings with regular updates, however, we realise that due to the pressure on the people at CERN this will be most effective if we can define what we want. When the target insertion tube is designed, we will check with Mario Scandura that it still fits in the current design. We will define a particular view of a drawing and request that it is made available via Lucie's drawing access system.
Double-decker targets: Originally, we wanted double targets to increase the rate, but since HARP is DAQ limited and not beam rate limited, this is not an advantage and single targets are best. However, if one compares a 2% with 2 x 1% targets, we need to think again. We discussed it in the meeting and still believe that the single target is the best (Due to the extra material for mounting the 2nd target which is in front of the first one. Anyway, we think that the correction for secondary interactions is small (~2%) and can be corrected out in the analysis to say 20% which is sufficient accuracy. We have the 45° target to cope with the larger correction which takes place at large angles. This argument should be presented to the collaboration ACTION: RE
Target thickness tolerance: We need to measure the target thickness to ~1% (in units of g/cm2). Experience from the muon scattering experiment shows that the mass can be determined easilly, but the area is dificult due to irregular cropping by Goodfellows. We will discuss the problem with Goodfellows ACTION: RN
Funding: (briefly)

Travel budget 6kGBP total this year, LTA would need case for particular person - this we will do for 2001 run.
Responsive RA bids sent from Sheffield and Oxford (Oxford did not get rolling grant post).
The Oxford RA is funded specially from Susan Cooper funds in belief that manpower is needed immediately and is on condition that we continue to persue conventional funding. Appologies that this was not clearly stated as we were writing the proposal.
RAL neutrino factory RA will work on HARP initially (start ~Sept 2000), RAL may have a HARP student, Sheffield have a CASE student.
Oxford are pursuing possibility for funding 6 months for a software expert based at CERN (subsistence ?).

List of targets:

Thin targets	Be	C	Al	Cu
	Sn	Ta	Pb
Cryogenic targets	H2	D2	N2	O2
Thick targets	C	Cu	Ta	Pb
Special targets	Li	Hg	K2K	Miniboone
Systematic targets	45° Al	Setup Cu	Empty

Consolidation of target list: This list is very long and we tried to reduce it somewhat. To be proposed by Rob at collaboration meeting ACTION: RE.

Remove Thin Ni (Its next to Cu, magnetic field problems)
Remove Thin W (It's next to Ta, difficult to machine, Ta is proposed for neutrino factory)
Remove Thick Al (For atmospheric neutrinos, thin targets only are neessary, we are also doing K2K)

Targets for technical run: Thin Cu and Setup target (Cu).
Target mounting: A long discussion about the target mounting followed. Time of course is short. We will certainly be able to provide an insertion tube for the September technical run (installation to be finished by 25 August), but it is clear that the complete assembly including the mounting rails will not be ready this early. Here is the prioritised plan of action: WORK FOR: AH, GB

Detailled drawing of insertion tube to be prepared so that it can be shown at CERN next week and we can receive clearance for manufacture.
Clear up whether a regulator plate is necessary or not.
Rough diagram of insertion rail system with dimensions so that other collaborators can see (and comment on) the space the apparatus will occupy.
Timescale for the design and manufacture of the rail system.

Software discussion: We discussed whether the UK should be involved in some additional activity to help the HARP experiment be ready on time. The consensus seems to be that software effort would be the most profitable way of contributing in an area which is in need of help in HARP. Sheffield are already involved in the simulation, help could arrive from RAL around September, Oxford can spend some time over the summer and we had ideas for how this could contribute in areas adjacent to Sheffield/RAL work.
Run 2000: Sheffield term starts 25/9, Oxford 2/10, so the run is very inconvenient for all. However, August seems to be a popular time for UK people to muck in at CERN. Assuming a fairly even allocation of shifts within the collaboration, we will probably need to do 2 shifts each this year. We should arrange a CERN team account.
Next meeting: Provisionally arranged for Friday 30th June in Sheffield.

Giles Barr