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the MICE beam line status

RATE in MICE BL much lower (~500 x) than requested to do physics The BL still need to be characterized: Progress during summer shifts heard Other needed: e.g. what is the ACTUAL EMITTANCE of the beam? Optics:

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the MICE beam line status

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  1. RATEin MICE BL much lower (~500 x) than requested to do physics • The BL still need to be characterized: • Progress during summer shifts heard • Other needed: e.g. what is the ACTUAL EMITTANCEof the beam? • Optics: • MuonBL: P=208 MeV/c, emi_N= 7 mm rad “ ... the mother of all the beamlines“ • Proton BL: derived from (a) by rescaling magnet currents according to local momenta. P=440 MeV/c. Used since Apr. 2008 for initial calibrations/set-up. W and WO decay solenoid (DS). • PionBL: from (a), ditto (b). P=440/300 MeV/c. W and WO DS • Electron BL: from (a), ditto (b). P=330 MeV/c. W and WO DS. Used for PID calibrations. NB: values currently used for the 1st triplet (from Logbook) are not the ones suggested in the Optics site. Has anyone a clue why? • NB1: many BLs for different flavours (p, p, m and e): needed for detector calibrations • A new WEB PAGE exists (with link to the old one) mice.iit.edu/bl • Regular bi-weekly meetings (started on 3/10/2008) the MICE beam line status

  2. Low proton/pion rate in MICE. • ISIS beam simulation (ORBIT, A.Dobbs: CM22 Sunday) and interaction with TGT  signals on BLM7,8 • Is pion capture optimal ? In other words, is the first Q-pole focusing at the right position? • Where is the tgt dipping ?  dimensional survey available MICE Note 216 • COMMENT: believe we will have to optimize our tgt dipping and negotiate with ISIS about beam losses. b) and c) can improve our rate • (and possibly explain other discrepancies) but they will NOT “recover” a factor 500. • PSI solenoid sick! Last coil missing  new optics sought. Which way (i.e. code?) • TPT/TTL (more natural and fast to define the optics) • G4MICE (I believe it is quite useful for a further hi-definition study) • G4beamline (as above) • Q.: check geometries vs dimensional survey To do list ... TOF work (M. Rayner): use TOF stations as emittance measurement devices (Analysis-CM22, Tuesday) Customize beamline using local momenta [CAVEAT still work in progress] http://www.isis.rl.ac.uk/accelerator/MICE/Task%20Notes%20and%20Specifications/beamline%20-%20optics/some_reference_data.htm General Optics Scaling Spreadsheet for commissioning(MA/KT): Here:- Beamline Scaling • Conversion field/current: status in the MLCR ? • A new web page is born ... Need to be filled • Complete the (e,P) matrix: • P=140/240 MeV/c, emi_N= 2,10 mm rad (*) (*) essential for commissioning

  3. ISIS-MICE TGT alignment purpose: understand sources of reduced rate comment: probably a 2nd order effect CAVEAT: result still preliminary, need a thorough check Please DON’T use them in your simulations !!! MICE Beam Line PC - 031008

  4. CAVEAT: used old drawings Author: MJK CLRC 2006 Plus some info from Note 216 486.05 MICE Beam Line PC - 031008

  5. Q4-point-1 Q4-point-6 1.76o Inclined_Frame_3 Inclined_Frame_2 Inclined_Frame_1 MICE Beam Line PC - 031008

  6. “nominal” target bottom tip Where is the actual intersection of Q-pole axis with tgt plane? Used 67.1-42.6=24.5 ISIS CL MICE Beam Line PC - 031008

  7. Q1

  8. Vert Pos is the DISTANCE FROM CL == Y

  9. TURTLE – a better look at the muon BL (just before D2 on)

  10. In Q4 After D1 Q5?

  11. Just before diffuser

  12. sY (cm) Turtle Simulation: KT BL design official doc D2 entrance sX (cm)

  13. 9/10 solenoid case – • a snapshot with Transport purpose: understand how the beam envelope changes when operating with a reduced solenoid == last coil silenced comment: we may want to know it for future decisions A finer assessment should rely on higher codes (G4XXX) MICE Beam Line PC - 031008

  14. Dx ~ 11 cm Dx ~ 5 cm Dx ~ 4 cm Dx ~ 9 cm • Used transport with (444 MeV/c pions): • http://www.isis.rl.ac.uk/accelerator/MICE/Task%20Notes%20and%20Specifications/beamline%20-%20optics/referencedecks&matching.htm • CM14-7.1-200 Transport.FILE1.dat • all DECAY SOLENOID red • reduced DS (9/10) cyan

  15. This is Kevin Optics for 440 MeV/c protons WITH NO SOLENOID MICE Beam Line PC - 031008

  16. Clearly removing the last coil from the solenoid introduces a growth of the beta: b0+(s-s0)2/b0 a linear growth in the envelope However a solution for 440 MeV/c from production to Q6 exists which Produces a decent result. I need to find the TPT deck and have some trials.

  17. (d) an example of beamline re-scaling for electrons (similar tables exist for p and pi) (using smart excel tables)

  18. (f) thanks Ken for the kickstart ...

  19. z x 35. 42.6 ~15. -578.5 MICE Beam Line PC - 031008

  20. z y MICE Beam Line PC - 031008

  21. ... a visual answer “nominal” target bottom tip 3.332o 3.046o ... here 256. ~15. 24.5 ISIS CL MICE Beam Line PC - 031008

  22. CONCLUSIONS with a caveat • from this preliminary study a misalignment is noticed which correspond to an angle of • 0.286o : it is the angle by which the bottom tip of the target (at its lowest point) sees • the entrance of Q1 • how important is this to pion collection at the 1st Q-pole? • my gut feeling says: not relevant • the real answer should rely on a MC simulation • I used an old reference (1st survey by CCLRC) because I think I understand the drawings. • Also partly used info from note 216, but I found it a bit more difficult to understand. • So I want to have the latest figures and re-calculate the axis of the q-poles towards the • target plane • before launching yourself into simulations let me be convinced of the numbers MICE Beam Line PC - 031008

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