We should plan on finishing target installation no later than June but the present goal should be to have everything ready for a minimal target by the first week of May with the cave closed up. FNAL needs 2 weeks dedicated to beam tuning with no access. The third week of April would be the soonest we could ask for the beam. We will likely still be fighting the target review but hope to be done by the first or second week of May.
Minimal target setup:
Fill Filling with commercial dewars or not: The main helium gas intake manifold is designed so that it is relatively easy to connect high purity commercial gas bottles, compress it and store it. If we fill the magnet and have enough to store for at least two other fills (or if we can find an FNAL protocol for storing additional LHe in the Hall or fill with LHe from a truck) then we can prepare to run a very minimalist target system to have some beam on target if this is relevant to either agency and/or the collaboration. It . The QT system can produce 200 L per day but our transfer is expected to be about 60% efficient. The magnet holds 40 L but depending on the starting temperature of the coils the magnet fill can require significantly more than 40 L. From about 80 K the fill would require about 300 L. If it's kept at about 4K than you only need about 150 L to fill. It would be possible to run the target system (magnet and fridge) for a couple of days in this way with even fewer electronics needed than what is listed in the critical path electronics. To polarize we need only a temporary microwave setup and polarization measurements. To measure the polarization we need the UVA NMR running in the Hall storing data to the NMR local machine. The is the minimalist polarized target system with no running roots and no continuous running QT system. One would get about 20% proton polarization achievable at any time of year even if other parts of the system are not yet leak-tight and/or ready to run. This is also a reasonable mode to begin commissioning the magnet.
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