1. Target/Beam Interaction M. Apollonio, A. Dobbs - IC 27/11/20081MICE Target Workshop - IC

2. Motivations: optimise secondary production minimising dangerous losses in ISIS assess better orientation/shape of the shaft for secondary production a work at “four hands”: A. Dobbs, ORBIT simulation of ISIS ring / interaction with target / comparison with data taken from MICE shifts, MA, G4Beamline simulation of secondary production with a set of shafts 27/11/20082MICE Target Workshop - IC

3. ORBIT Results 27/11/20083MICE Target Workshop - IC A. Dobbs

4. 25/11/08ORBIT Results, Adam Dobbs4 Target Orientations (variable depths) “Short-Fat” – 1mm along z – axis, 10mm along x - axis “Long-Thin” – 10mm along z – axis, 1mm along x – axis (true orientation) “Reduced” – 1mm along z – axis, 1mm along x - axis 27/11/20084MICE Target Workshop - IC x y s

5. 25/11/08ORBIT Results, Adam Dobbs5 Injection losses MICE target losses Short-Fat: 27mm above axis, -1 to 10ms 27/11/20085MICE Target Workshop - IC zoom last 2 ms

6. 25/11/08ORBIT Results, Adam Dobbs6 Long-Thin: 27mm above axis, -1 to 10ms (NB: present config) 27/11/20086MICE Target Workshop - IC

7. 25/11/08ORBIT Results, Adam Dobbs7 Short-Fat: 27mm above axis, 8 to 10ms 27/11/20087MICE Target Workshop - IC

8. 25/11/08ORBIT Results, Adam Dobbs8 Long-Thin: 27mm above axis, 8 to 10ms 27/11/20088MICE Target Workshop - IC

9. 25/11/08ORBIT Results, Adam Dobbs9 Long-Thin: 26mm above axis, 8 to 10ms 27/11/20089MICE Target Workshop - IC

10. 25/11/08ORBIT Results, Adam Dobbs10 Long-Thin: 27mm above axis, 25 0 rotation, 8 to 10ms NB At present there remains an ambiguity in the direction of the rotation, clockwise or anti-clockwise. If / when this is resolved it will be published in an updated version of this document. 27/11/200810MICE Target Workshop - IC

11. 25/11/08ORBIT Results, Adam Dobbs11 Reduced (1mm^2): 27mm above axis, 8 to 10ms 27/11/200811MICE Target Workshop - IC

12. 25/11/08ORBIT Results, Adam Dobbs12 Reduced: 26mm above axis, 8 to 10ms 27/11/200812MICE Target Workshop - IC

13. 25/11/08ORBIT Results, Adam Dobbs13 Reduced: 25mm above axis, 8 to 10ms 27/11/200813MICE Target Workshop - IC

14. 25/11/08ORBIT Results, Adam Dobbs14 Reduced: 24mm above axis, 8 to 10ms 27/11/200814MICE Target Workshop - IC

15. Circular-solid 6mm radius: 27mm above axis, 8 to 10ms 27/11/200815MICE Target Workshop - IC

16. G4Beamline Studies 27/11/200816MICE Target Workshop - IC M. Apollonio

17. 27/11/200817MICE Target Workshop - IC - is there a better shape for the target or orientation? - how many secondaries (pi) do we get at the Q1 bore (per impinging proton?) - what about materials? ISIS p trajectory Q1-2-3 25 o MICE TGT

18. 10 mm X Z 25 deg Q1-TGT axis 25 deg lost to Q1 secondaries production 20<theta<30 propagation to plane A acos(Pz/Ptot)>20 && acos(Pz/Ptot)<30 rotation & propagation to plane B A A B C shift & align with Q1-TGT axis LONG SLIM 18

19. 25 deg FAT SHORT TILTED TGT 10 o / 25 o 27/11/200819MICE Target Workshop - IC

20. 25 deg Cylinder: OD=6mm/ID=4.7 mm Materials: Ti Be Al 27/11/200820MICE Target Workshop - IC

21. Tgt_long_slim_rot0: y:x Nprimaries=100M 27/11/200821MICE Target Workshop - IC A

22. Tgt_long_slim: y:x rotation 25 deg + shift 4.226 27/11/200822MICE Target Workshop - IC B NB: this particles (ROOT file) are shooting towards Q1and can be used as an input beam for further simulations

23. 27/11/200823MICE Target Workshop - IC at Q1 plane in Q1 bore C

24. 27/11/200824MICE Target Workshop - IC

25. 27/11/200825MICE Target Workshop - IC

26. 27/11/2008MICE Target Workshop - IC

27. 27/11/200827MICE Target Workshop - IC CONCLUSIONS - neither the shape nor the orientation of a target seem to alter significantly the production of secondaries to Q1 - the overall material volume intercepted by the beam is the main parameter (reasonable) - material other than Ti (lower A/rho) generate less secondaries (in particular pions) -a good balance should be found between weight / mechanical stiffness / and pion production -a hollow cylinder is a good solution, certainly does not worsen the performances of the present configuration