Technical Challenges of future neutrino beams

Mary Anne CummingsNorthern Illinois University

WIN ’03Lake Geneva, Wisconsin

The current story..

Recent results from SNO and SuperK have convinced most of the HEP community that ’s oscillate, most likely among 3 known species

There exists now ongoing R & D in accelerator and experimental physics based on beams, and the beams that can be extracted from them.

New machines can be developed in an incremental fashion, with a physics program for each step.

Proton drivers can provide intense conventional beams, and can provide an intense source of low energy ’s (via decay)

These ’s must be cooled – an very active R & D program has sprung from developing this new technology.

As a proton driver is being constructed, work on collecting the ’s and cooling them would be continued.

An intense source of cold muons could be immediately used for E and B dipole moments, muonium-antimuonium oscillations, rare decays…

As cooling and acceleration capability is developed, a storage ring could be the basis of the first neutrino factory.

Source of e’s and v’s and their charged conjugates from + an - beams During factory construction, further R & D on acceleration can create

a Higgs factory and higher energy muon colliders … using relatively compact collider rings

A bit of background

Concept of a muon collider: Tinlot (1960), Tikhonin (1968), Budker (1969), Skrinsky

Neuffer (1979), Palmer (1995) Muon Collider Collaboration

Many advantages over electron collider comes from the mass of a muon:

But, they decay, and luminosity becomes a challenge

Fast cooling technique – ionisation cooling – invented 1981:Skrinsky and Parkhomchuk

Another problem…….neutrino radiation!

Idea for a Neutrino Factory comes from seeking a use for beams produced a muon collider storage rings.. this turns out to be very positive! (S. Geer, 1997 FNAL workshop)

207emm

Neutrino Neutrino Factory!Factory!

Enough neutrinos to be a problem …. must be enough to do physics

- R. Edgecock

Muon Collaboration

• Now referred to as the Neutrino Factory and Muon Collider Collaboration– > 140 scientists– MC is sponsored by three national laboratories (BNL, FNAL, LBNL)

• Active Program:– Targetry– Cooling Simulations– RF Hardware – LH2 absorber Designs– High-field solenoids– Emmitance Exchange– Muon Acceleration– Neutrino Factory design studies I and II

• Experiments:– MUCOOL (FNAL) : Cooling channel component development: MTA completed!– MICE (Rutherford-Appleton) Muon cooling measurement: Approved!

• University Participation:– ICAR (Illinois Consortium for Accelerator Research)– Ph.D. and Masters students involvement– State of Illinois support to promote accelerator R & D

Not THAT ICAR…• xx•

• New Book by David M. Jacobs!• Thinking Clearly About UFO Abductions• Video Interview with David Jacobs

• • xxx•  

• Welcome to the ICAR•

• Straight Talk About UFO Abductions• The International Center for Abduction Research (ICAR) is an organization devoted to the dissemination of trustworthy information about UFO abductions. The ICAR will provide accurate information to therapists and lay individuals who are interested in abductions, and help cope with the myriad of problems that arise from the use of hypnosis and other memory collection

procedures. David M. Jacobs is the Director of the ICAR and there is a small Board.• A personal note from David M. Jacobs:

I wrote most of the information on this website based on thirty-four years of UFO research and over twelve years of hypnotic regressions with abductees. I have tried to be as objective and as "agenda free" as possible, sticking close to the evidence that I have gathered over the course nearly 800 hypnotic regressions. However, there is no possibility that I have avoided error. The reader must be skeptical of what I say and what all others say in this difficult arena of abductions, hypnosis, popular culture, and cultural expectations. We are all amateurs doing our best to get to the truth knowing that objective reality may elude us.

Muon Collider R & D

Three stage scenario:Neutrino FactoryHiggs FactoryMuon Collider

5 different Neutrino Factory layouts: BNL

CERNFNAL

J-PARC RAL

For example, at least 2 generations of colliders would fit on FNAL site…

Technical Issues:Technical Issues:

1. Proton driver

2. Target and Capture

3. Decay and Phase Rotation

4. Bunching and Cooling

5. Acceleration

6. Storage Ring

BUT…BUT…

Large PH init. Large PH init. beam beam rapid beam rapid beam coolingcooling

Short lifetime Short lifetime rapid rapid acceleration acceleration

Backgrounds:Backgrounds:

Muon colliders: compact design

Technical Staging and Physics

Muon Collider SchematicMuon Collider Schematic

Study II Study II factory.. factory..

Possible Higgs factory..Possible Higgs factory..

JHF Superbeam

Kobayashi

ProtonBeam

Target FocusingDevices

Decay Pipe

Beam Dump

,K

“Conventional” neutrino beam

TargetHornsDecay Pipe

Far Det.“Off-axis”

Proton Driver

Main requirements:

4 MW beam power, 1 ns bunch length, 50Hz

Two types:Linac (BNL type) RCS (FNAL type)

Range of energies:

2.2 to 50 GeV

BNL, FNAL parameters:

R & D: HIPPI

Target

Proposed rotating tantalum target ring

Many challenges: enormous power density lifetime problems pion capture

Replace target between bunches:

Liquid mercury jet or rotating solid target

Stationary target:

RAL

CERN

Liquid Mercury Tests

Tests with a proton beam at

BNL.

• Proton power 16kW in 100ns Spot size 3.2 x 1.6 mm

• Hg jet - 1cm diameter; 3m/s

0.0ms 0.5ms 1.2ms 1.4ms 2.0ms 3.0ms

Dispersal velocity ~10m/s, delay ~40s

Target Facility

Carbon or liquid mercury jet target

20 Tesla capture solenoid

Issues: 1.power dissipation,

target durability2.pion yield of solid &

liquid target3.performance of

capture solenoid in a high radiation environment

Pion Capture

20T 1.25T

Horn Capture

Protons

Current of 300 kA

To decay channel

Hg target B1/R

B = 0

Phase Rotation & Bunching

Beam after drift & adiabatic buncher – Beam is formed into string of ~ 200MHz bunches

Beam after ~200MHz rf rotation; formed into string of equal-energy bunches;matched to cooling RF acceptance

1B & R

2R & B

Alternative:1. Rotation by induction Linac (E-field

gradient on axis) into longer pulse, lower energy spread

2. Bunching by RF lattice (similar to cooling channel) into 200MHz

Ionization Cooling

With transverse focussing (solenoid) ~ beam envelope:

Rμ3

trans

xx

LmEβ

βf

L

ε

dz

dεHeating term (mult.scatt.)

Cooling term

x x

z zP1

P2

absorber

accelerator accelerator

absorber

P1

Multiple scattering

RF cavity RF cavity

The miracle of muons is that they can focus going through matter!

Phase space equation:

Liouville’s Theorem states that phase space is invariant.. need to remove energy to increase particle density…

LR large LH2

Transverse Cooling Channel Design

Shown here, a cooling cell with LH2 Absorbers, RF cavities and Solenoid Magnet:

Issues:LH2 safety, windows strong but thin, RF cavities

“benign”, structural intregrity in very large E and B fields

Ignition source: very high E fields!Incendiary

device (LH2)

Quench site: very high B

fields!

MuCool ResearchCurrent experiments at laboratories and universities.

LH2 WindowsPhotogrammetry:Non-contact measurement of strain by calculating displacement

Photogrammetry ~1000 points

Strain gages ~ 20 “points”

MuCool/ICAR researchCurrent design and simulation programs atlaboratories and universities.

Cooling channel RF cavities…

Large E fields inside of large B fields!

Large E field: cavity performance is determine by field emission from surface.

MTA LH2 Experiment

Beamline: C. Johnstone

Mucool Test Area LH2 Setup

Lab G magnet

MICE

T.O.F. IIIT.O.F. IIIPrecise timingPrecise timing

Electron IDElectron IDEliminate muons that decay Eliminate muons that decay

Tracking devices: Tracking devices: He filled TPC-GEM (similar to TESLA R&D)He filled TPC-GEM (similar to TESLA R&D)or sci-fior sci-fiMeasurement of momentum angles and positionMeasurement of momentum angles and position

T.O.F. I & IIT.O.F. I & IIPion /muon IDPion /muon IDprecise precise timingtiming

201 MHz RF cavities

Liquid H2 absorbersor LiH ?

SC Solenoids;Spectrometer, focus pair, compensation coil

Muon Ionisation Cooling Experiment: Approved by RAL

Technical Design Report in December

Muon Acceleration

Needs to be fast – muon lifetime

Needs to be a reasonable cost – not all linacs all the way

Baseline: Recirculating Linear Accelerators

• Other possibilities…… FFAGs & VRCS

FFAGs

• Fixed Field Alternating Gradient magnets not ramped

krB ~

Cheaper/faster RLAs/RCSs

Large momentum acceptance

Large transverse acceptance less cooling required!

Neutrino Factory Neutrino Factory

Japanese staged physics Japanese staged physics programprogram

• High Power Proton Driver– Muon g-2

• Muon Factory (PRISM)– Muon LFV

• Muon Factory-II (PRISM-II)– Muon EDM

• Neutrino Factory– Based on 1 MW proton beam

• Neutrino Factory-II– Based on 4.4 MW proton

beam• Muon Collider

FFAG’s

Proof Of Principle machine built and tested in Japan.

50keV to 500keV in 1ms.

150MeV FFAG under construction at KEK.

VRCS

Fastest existing RCS: ISIS at 50Hz 20ms

Proposal: accelerate in 37s 4.6kHz

Do it 30 times a second

920m circumference for 4 to 20 GeV

Combined function magnets 100 micron laminations of grain oriented silicon steel 18 magnets, 20T/m

Eddy currents iron: 100MW 350kW Eddy currents cu : 170kW

RF: 1.8GV @ 201MHz; 15MV/m

Muons: 12 orbits, 83% survival

Parting Remarks

Neutrino oscillations: one of most important physics results

Many new experiments conceived

New beam neutrino facilities required :- Superbeams - - Neutrino Factory- Beta beams

All require extensive R&D

For Neutrino Factory: a thriving research program- proton driver

- target - cooling (MuCool, MICE)

- acceleration

Real Experiments are planned and approved