1. Current Status and Possible Items around ‘neutrino beam’ Horn Target Remote maintenance tools Decay volume window and collimator muon monitor Many items are still conceptual design stage. Which item can be shared or brought to outside collaborators is not yet clear. In this note, some possible items are listed for the first step of cooperation. Here, I assume technical contribution (not financial one). For discussion w/ Eric Zimmerman, 11/Mar/04

2. Horn –status- Proto-type for 1st horn inner conductor was ordered. Outer diameter is 60mm. Test w/ K2K outer conductor and power supply will be done. Cooling test set up for 1st horn inner conductor have arrived. Test of nozzle will be done. Stress Analysis 1st horn final(?) stress analysis will be done after we fix the nozzle design. 2nd and 3rd horn stress analysis was just started. Inner conductor shape will be optimized.

3. J-PARC Neutrino Horn System 1st 2nd 3rd 320kA 320kA 320kA

4. 1 st Horn Inner Conductor

7. Cooling Test setup

8. Horn Possible contribution items Cooling system test for 2 nd and 3 rd horns. Our set up is rather small system. Coupling of strip lines which can be coupled/decupled remotely. Coupling of water pipe which can be coupled/decupled remotely. Many know-how on parts from the MiniBooNE horn. (bolts, insulators….) (Remote) Alignment system required accuracy ~1mm.

9. Target current status Effect of radiation is being studied. ~0.26 dpa/yr shrinkage, worse conductivity, swelling are problem. We have a one basic design w/ water cooling. Coaxial two water paths. However water cooling has problems. shrinkage inside container, pressure of instantaneous temperature rise of water Therefore, we started to think about He cooling. Can be operated at rather high temperature, hence lower radiation effect. Coaxial two flow paths. ~30m/s @ 5 atm. For the compressor, we are onsulting cryo. group at IPNS, KEK Cooling path material Start basic designing w/ Al, Ti and C/C composite Insulator from horn(~1kV) Start thinking about ceramics and plasma sprayed alumina.

10. horn Graphite target flow

11. Remote Maintenance Side View Top View Disconnect Horn and it’s support structure including strip-lines. Is this realistic? Residual radiation level should be checked. Anyway, we need remotely connectable/dis-connectable cuppling For strip-lines and water pipes.

12. DV collimator Need cooling Almost no work yet.

13. DV window Strategy If we put a DV window, it might be broken by heat load. Cooling is also problem. Since the target station will be filled with He, DV window is not necessary during operation. However, w/o window, each time we open the target station, He inside DV must be released. It will need time and cost. Therefore, we are planning to make a movable window which opens during operation and be closed during maintenance at the target station. The window must withstand the evacuation of the target station and DV. The window must be installed from upside.

14. K2K DV window

15. Muon Monitor J. Kamda(KEK) has been working on muon monitor. But he will move to ICRR. TRIUMF has an interest on a diamond detector. In addition to these solid detectors, ionization chamber should be installed. For muon monitor, presentation by J. Kameda at NBI is useful. ( http://www-ps.kek.jp/~nbi2003/presentation/index.html)http://www-ps.kek.jp/~nbi2003/presentation/index.html