mice

1MICE beam line review 16-11-2007 Alain Blondel

MICE

The International Muon Ionization Cooling Experiment


MICE Overview

1. Why, what and how?

2. requirements on the beam line

3. other desirable features of the beam line

3. Conclusions


High-power target . 4MW . good transmissionMERIT experiment (CERN)

Major challenges tackled by R&D expts

Fast muon cooling MICE experiment (RAL) , MUCOOLFast, large

aperture accelerator (FFAG)EMMA (Daresbury) ISS baseline


IONIZATION COOLING

principle:

this will surely work..!

Difficulty: affordable prototype of cooling section only cools beam by 10%, while standard emittance measurements barely achieve this precision.Solution: measure the beam particle-by-particle

Cooling is necessary for Neutrino Factory and crucial for Muon Collider.Delicate technology and integration problem Need to build a realistic prototype and verify that it works (i.e. cools a beam)

Can it be built? Operate reliably? What performance can one get?

state-of-the-art particle physics instrumentation will test state-of-the-art accelerator technology.

reality (simplified)

….maybe…


Incoming muon beam

VariableDiffuser

Beam PIDTOF 0

CherenkovTOF 1

Trackers 1 & 2 measurement of emittance in and out

Liquid Hydrogen absorbers 1,2,3

DownstreamTOF 2

particle ID:KL and SW Calorimeter

RF cavities 1 RF cavities 2

Spectrometer solenoid 1

Matching coils 1&2

Focus coils 1 Spectrometer solenoid 2

Coupling Coils 1&2

Focus coils 2 Focus coils 3Matching coils 1&2

10% cooling of 200 MeV/c muons requires ~ 20 MV of RF single particle measurements =>

measurement precision can be as good as out/ in ) = 10-3

never done before


Focus coils and LH2 Absorbers

Coupling coils and200 MHz RF Cavities

Solenoids, Matching coils and

Scintillating fiber Tracker

CKOVToF0

ToF1,diffuser

ToF2,Calorimeter

More professionally engineered view:


Universite Catholique de Louvain, Belgium

University of Sofia, Bulgaria

The Harbin Institute for Super Conducting Technologies PR China

INFN Milano, INFN Napoli, INFN Pavia, INFN Roma III, INFN Trieste, Italy

KEK, Kyoto University, Osaka University, Japan

NIKHEF, The Netherlands

CERN

Geneva University, Paul Scherrer Institut Switzerland

Brunel, Cockcroft/Lancaster, Glasgow, Liverpool, ICL London, Oxford, Darsbury, RAL, Sheffield UK Argonne National Laboratory, Brookhaven National Laboratory, Fairfield University, University of Chicago, Enrico Fermi Institute, Fermilab, Illinois Institute of Technology, Jefferson Lab, Lawrence Berkeley National Laboratory, UCLA, Northern Illinois University, University of Iowa, University of Mississippi, UC Riverside, University of Illinois at Urbana-Champaign USA

THE MICE COLLABORATION -128 collaborators-

8MICE beam line review 16-11-2007 Alain Blondel 200MHz RF cavity with beryllium windows

Liquid-hydrogen absorbers

Scintillating-fiber tracker

MICE

Status: Approved at RAL(UK)First beam: 10-2007

Funded in: UK,CH,It,JP,NL,USFurther requests: JP,UK,US,It...

Single-beam ~200 MeV/c

4T spectrometer I

4T spectrometer II

TOF

Cooling cell (~10%)=5-45cm, liquid H2, RF

Final PID:TOFCalorimeter

Demonstrate feasibility and performance of a section of cooling channel by 2010

Prototyping:

FIRST BEAM IN FEBRUARY 2008


MICE STEPS and PHASES

Febuary 2008

STEP I

April 2008

STEP III July 2008

STEP II

STEP IV Delivery of 1st FC~May 2009

STEP V >summer 2009

STEP VI 2010

PHASE I

PHASE II


MICE StatusFundingFunding for Phase I is secured some pending issues with INFN, support for visitors at RAL, beamline electricityFunding for Phase II is essentially secure (excellent news from US, China summer07) BUT: UK Phase II still awaiting decision, Japan for absorbers, SW calorimeter ConstructionDAQ, CKOV1 arrived at RAL in July 2007 Tracker I arrived at RAL Nov14 2007 Combined Cosmic Test in November-December Beam line construction in full swing; will be closed and safe by Jan20 2008

TOF0/1, KL: detectors built, mechanics finishing, ETA at RAL 15 Dec 2007Spectrometer solenoid I to arrive FNAL jan 2008 and RAL March 2008Tracker II to arrive RAL in Feb 2008Spectrometer solenoid II to arrive RAL in May 2008 TOFII June 2008SW later in 2008

step IV to be defined by AFC module I. Tender issued. OK from UK-STFC pending global review result end of 2007.

Crucial issue for PhaseII is RF tests in magnetic field: RF cavity I arrived in 2006, tested to 19MV/m coupling coil I will arrive FNAL end 2008.


Challenges of MICE: (these things have never been done before)

1. Operate RF cavities of relatively low frequency (201 MHz) at high gradient (nominal 8MV/m in MICE, 16 MV/m with 8 MW and LN2 cooled RF cavities)

in highly inhomogeneous magnetic fields (1-3 T) dark currents (can heat up LH2), breakdowns

2. Hydrogen safety (substantial amounts of LH2 in vicinity of RF cavities)

3. Emittance measurement to relative precision of 10-3 in environment of RF bkg

requires low mass (low multiple scattering) and precise tracker fast and redundant to fight dark-current-induced background precision Time-of-Flight for particle phase determination (±3.60 = 50

ps) complete set of PID detectors to eliminate beam pions and decay

electrons

and…

4. Obtaining (substantial) funding for R&D towards a facility that is not (yet) in the plans of a major lab


equilibrium emittance = 2.5 mm.radian

curves for 23 MV, 3 full absorbers, particles on crest

Beam optics and diffuser to providethis set of emittancesChangeover should be fast (30')and should not require switching offMICE magnets.

MICE diffuser system:

The experiment MICE wants to do

repeat this curve for various momenta, absorbers, etc..


Design of MICE detectors and beam test results satisfy the above requirements

Requirements on detectors for MICE:

1. Must be sure to work on muons 1.a use a pion/muon decay channel with 5T, 5m long decay solenoid 1.b reject incoming pions and electrons TOF over 8m with 70 ps resolution+ threshold Cherenkov 1.c reject decays in flight of muons downstream PID (TOF2 + calorimeters)

2. Measure all 6 parameters of the muons x,y,t, x’, y’, z=E/Pz tracker in magnetic field, TOF

3. Resolution on above quantities must be better than 10% of rms of beam at equilibrium emittance to ensure correction is less than 1%. + resolution must be measured

4. Detectors must be robust against RF radiation and field emission


MICE is a precision experiment!

Cooling in MICE is only ~10% ((outout inin))exp exp = 0.9 = 0.9 establishing effect requires % precision, optimizing it requires permil precision

This is the goal of MICE.

requires:

statistics of 106 muons per measurement point (a few hours at 100 good muons/s)

systematics at permil level, individual sources must be a small fraction of this!

Beam related systematics In principle, individual muons can be reweigted to form an 'ideal beam' This is not very easy – avoid reweighting factors of more than ~50% overall Alignment in x,x', y,y', p has been studied and leads to the constraint that

beam offsets should not exceed 3-5% of beam sizes at diffuser

Effect of mismatch, x-y asymmetries, coupling, dispersion have not been completely studied


Mice-fiction in 2009 or so. Mice-fiction in 2009 or so.

. MICE measures e.g. (. MICE measures e.g. (outout inin))exp exp = 0.904 = 0.904 ± 0.001 (statistical)± 0.001 (statistical)

and compares with (and compares with (outout inin))theory. theory. = 0.895 = 0.895

and tries to understand the difference.

SIMULATIONSIMULATION

REALITYREALITY

MEASUREMENTMEASUREMENT

theory systematics: modeling of cooling cell is not as reality

experimental systematics:modeling of spectrometers or beam is not as reality

Experimental Systematics


Requirements on MICE beam -- 'single' muons of either sign (low intensity, long spill, t >~ 100 ns) -- beam momentum: 140MeV/c – 240 MeV/c (MICE channel momentum range) + higher momentum desirable: 240 + 1p = 265 MeV/c to cover phase space incl. amplitude-momentum correlation.

-- emittance: optically matched, 1-10 mm.rad, symmetric in x-y, p /p ~ 10%

from: below equilibrium emittance (2.5 mm.rad) <== this is not easy to: exceed acceptance of MICE (10 mm rad) -- time structure: pulse duration*rep rate = RF duty factor of 0.001 this is achieved with rep. rate 1Hz and pulse length of 1ms (ISIS)

-- statistics: ~ 100 good muons per second (i.e. within 15cm radius in tracker) this requires 600 good muons per pulse (to allow RF timing cut of 1/6) Fewer muons --> run the facility longer, cost more!

-- alignment: requires offset < 3% of beam size at MICE (small reweight) i.e. ~1mm centering in x,y ~3mrad in x' y' at absorber -- purity: electrons and protons are easy to discriminate (if not too numerous) pion/muon contamination should be less than 1/10 (1/100 desirable)


Beam Line Review

1 November 2007

Beam Line Design and Commissioning Review

Agenda

16th November 2007, Room 539, Blackett Laboratory, Imperial College London 09:00 Executive session: 09:30 Presentations: 1. MICE Overview [Blondel, Long, or Zisman] [25+5] 2. Beam Line Design: Guiding principles & expected capabilities [Tilley] [30+10] 3. Simulation comparison /design tools/issues [Nebrensky] [20+5] 4. Diffuser Issues [Apollonio] [20+5] 5. Diffuser Mechanical Design [Yang or Lau] [15+5] 6. Diffuser control system [Apollonio] [15+5] 13:00 Lunch 14:00 Presentations: 7. Magnet refurbishment, measurement, installation [Flower] [25+10] 8. Commissioning Plans [Tilley] [25+10] 9. Beam Line Diagnostics [Kyberd] [15+5] 15:30 Executive session:

Preparation of additional questions and close-out 16:00 Close-out: 10. Closeout [45] 11. Adjourn

1 November 2007

Beam Line Design and Commissioning Review Charge to Committee

Background The general purpose of the review is to evaluate the final design of the MICE muon beam line, its implementation plan, and the initial plans for its commissioning. The current MICE schedule calls for the installation to be complete, and for commissioning to commence, in January 2008. The line comprises two sections:

1. an upstream portion to transport the pion beam from the production target through the decay solenoid;

2. a downstream portion to transport the muon beam from the decay solenoid to the entrance to the MICE experiment, and to optically match the beam into the upstream spectrometer solenoid.

Design Goals It is required that:

muon beam purity be as high as possible; muon beam momenta in the range of roughly 140 MeV/c to 240 MeV/c, with a

momentum spread of up to ±10%, be transportable by suitably tuning the beam line; and

matched emittance values in the range 1 mm-rad N 10 mm-rad be deliverable to MICE.

Charge

1. Review and comment on the optical design of the line, and its ability to fully or partially meet its design goals.

2. Review and comment on plans and schedule for magnet refurbishment, magnetic field measurements, fiducialization, installation, alignment, and testing.

3. Review and comment on plans for initial commissioning of the beam line, including the adequacy of proposed diagnostic devices.

Prepare a written summary of findings for the MICE experiment management (Spokesperson and Project Manager) within one week from the review.


Target mechanism has been developed to dip Ti target into ISIS beam in the last ms of ISIS cycle

80 g acceleration achieved !1 Hz rateTested with >3M actuations Wear solved with Diamond bearingsWill be installed in Xmas 07 shut down

Target and time structure

micro structure:

330ns 100ns

detectors and DAQ well adapted to this structure


The MICE BEAM LINE


Upstream beam line: Xmas work

VERY TIGHTworking hard


Beam line

-- Construction at RAL is in full swing

main issues: -- target just in time.. now authorized! to be installed over X-mas-- repairing the PSI solenoid and cold check-- original misalignment of assumed point of target impact on beam by 2cm... being fixed-- Q4-6 refurbishment finished; Q7-9 still ongoing tight schedule-- schedule of Xmas shut down is very tight! -- beam monitors and TOF0 are all somewhat late risk: delays in startup

At this point the beam line does not include: -- collimators (maybe needed for small emittance beam) -- alignment correctors there is a couple schemes possible, but not completely worked out correcting dipoles or trim coils on quadrupolesrisk: loss of performance and practicality

-- ratio of particle production to beam loss monitors not completely understood risk: considerable loss of performance.


Aspirational MICE Schedule as of October 2007

Febuary 2008

STEP I

April 2008

STEP III July 2008

STEP II

STEP IV Delivery of 1st FC~May 2009

STEP V >summer 2009

STEP VI end 2009 (or 2010)


Run plan -- steps I and II

STEP I Jan-Feb 2008

STEP II march –April 2008

Goals: I – Commission targetEstablish beam ratesFind match and alignment

II - Determine whether we have all knobs necessary to draw emittance vs. transmission curve. Measure emittance

preliminary estimate

STEP I requires 60 shifts (20 days of running) beam line commissionning, target tuning (rates), DAQ and detector shake down

STEP II requires 150 shifts (50 days, will extend in summer 2008) Alignment of beam x,x’,y,y’, (Lack of) dispersion, check range of transverse emittance, and range of momentameasure emittance and… publish first paper

total for steps I & II: 70 days

Runnng time:Take 200-400 muons per 1ms spill once per secondIn steps I-IV 1% (0.1%) emittance meast will take ~1 (100) minute 6 times longer in steps V and VI where phase matters.


0. MICE will be taking data in 75 days

1. The collaboration is making excellent progress in all fronts:Simulations, R&D, engineering, prototyping and construction Funding for phase I is complete,

Funding for PhaseII is in good shape to assure that step VI can be performed in good time for 2010.

2. MICE will start phase I data taking in february 2008

Steps I, II, III will allow beam commissioning, tuning, first measurement of emittance and verification of systematics

3. The MICE beam line has been designed to provide adequate statistics and the range of momentum and emittances needed to measure transmission, cooling and equilibrium emittance with high precision.

4. To the reviewers:

you will do MICE a great help by finding the bug before we find it the hard way in 2008. THANKS!

Conclusions

mice

Documents

university of illinois

beam line construction

kyoto university

osaka university

university of chicago

university of iowa

fairfield university

university of mississippi