1. MICE

2. Outline Experimental methods and goals Beam line Diagnostics – In HEP parlance – the detectors Magnet system 2MICE Optics Review January 14, 2016 Alan Bross

3. Methods MICE was conceived to demonstrate muon- ionization cooling MICE’s experimental method is to measure the trajectories of individual particles and then build a beam emittance from these individual measurements – HEP methodology as opposed to techniques typically used accelerator physics experiments Cooling(heating) is then just the difference of two selected ensembles (out-in/in) 3MICE Optics Review January 14, 2016 Alan Bross

4. Goals MICE will be performed in two steps – No re-acceleration – measure the properties of H 2 and LiH absorbers and measure transverse normalized emittance (  ⊥ )reduction: Step IV – Measure emittance reduction in a complete cooling cell including re-acceleration (RF): Demonstration of Ionization cooling 4MICE Optics Review January 14, 2016 Alan Bross

5. Ionization cooling is the only known approach that cools muons fast enough MICE Optics Review January 14, 2016 Alan Bross5

6. Working points 140 MeV/c – Initial emittance ~4 mm 200 MeV/c – Initial emittance ~6 mm 240 MeV/c – Initial emittance ~7 mm 6MICE Optics Review January 14, 2016 Alan Bross

7. Muon Beam A Ti target is dipped into the halo of the ISIS proton beam at ~ 1 Hz in order to produce pions which are collected and transported to a decay solenoid where they are allowed to decay into muons. Two large aperture dipoles and three quad triplets comprise the MICE muon beam line – Note: Beam line settings can allow for pion-rich or electron- rich beams in addition to MICE’s normal muon beam Beam is essentially DC – particles occur more less uniformly within the 100 ns bucket – 3 MHz ISIS RF – 220 ns + 100 ns – However, occupancy is very low (<< 1/bucket) 10-100 particles per dip ( in 1msec spill). 7MICE Optics Review January 14, 2016 Alan Bross

8. Beam line 8MICE Optics Review January 14, 2016 Alan Bross

9. Diagnostics aka The detectors Particle ID (muon/pion/electron) – Incoming: Time-of-flight (timing) + CKOV – Outgoing: TOF + KL (preshower) + EMR (totally active, tracking calorimeter) Position and momentum measurements – 2 scintillating fiber trackers in “nominal” 4T field 9MICE Optics Review January 14, 2016 Alan Bross Step IV

10. Detectors II All detectors are commissioned and operating at or very close to specification Continuing work: – Calibration of tracker readout – Some minor issues with TOF and CKOV – KL and EMR fully vetted at this point Refs: – Tracker: Nucl.Instrum.Meth. A (659) 136-153 (2011) – EMR: 2015 JINST 10 P12012 – Beam line: European Journal of Physics C, Volume 73, Number 10 – Instrumentation: Journal of Instrumentation, Volume 7, Number 5 10MICE Optics Review January 14, 2016 Alan Bross

11. Absorbers In Step IV, MICE will investigate both LH 2 and LiH In the demonstration of ionization cooling, MICE will use a central absorber consisting of a 65 mm thick LiH disk, plus two secondary absorbers of LiH of 30 mm thickness each. 11MICE Optics Review January 14, 2016 Alan Bross

12. Magnets Step IV 12MICE Optics Review January 14, 2016 Alan Bross X or LiH

13. Damaged downstream spectrometer solenoid magnet You will see in the talks that follow, that MICE will be able to delivery on the majority of its Step IV program, even without the one coil (Match 1) of SSD. However, the event that made the M1 coil of SSD unusable also compromised a vacuum feed through (vacuum space to LHe space) for the power leads for the M1 and M2 coils The risk of a catastrophic vacuum failure is high. Step IV could end prematurely In addition, the demonstration of ionization cooling step would not be viable without a functioning M1 in SSD Therefore, we will run Step IV while, in parallel, we have initiated a process to repair or replace SSD – As endorsed by a recent MAP Director’s review and presented to DOE and STFC 13MICE Optics Review January 14, 2016 Alan Bross

14. Magnets Demo of ionization cooling 14MICE Optics Review January 14, 2016 Alan Bross

15. Conclusions MICE beam line fully functional MICE diagnostics (detectors) commissioned and ready for data The MICE magnet system has been compromised, but the Step IV program is still robust SSD will be repaired or replaced and the MICE cooling demonstration with RF will operate in its baseline configuration 15MICE Optics Review January 14, 2016 Alan Bross