DAE ALUS A Path to Measuring CP Using Cyclotron Decay-at-Rest - - PowerPoint PPT Presentation

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DAE ALUS A Path to Measuring CP Using Cyclotron Decay-at-Rest - - PowerPoint PPT Presentation

Oct 12, 2023 211 likes •641 views

DAE ALUS A Path to Measuring CP Using Cyclotron Decay-at-Rest Neutrino Sources NOW 2012 Matt Toups, MIT M. Toups, MIT -- NOW 2012 1 A two-part talk: 1. The experimental design for the flagship measurement: CP Violation 2. Implementing

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DAEδALUS

A Path to Measuring δCP Using Cyclotron Decay-at-Rest Neutrino Sources

NOW 2012 Matt Toups, MIT

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  • 1. The experimental design for the flagship measurement:

CP Violation

  • 2. Implementing a phased approach with rich physics, highlighting:

The IsoDAR sterile neutrino program (Phase II)

A two-part talk:

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  • 1. The experimental design for the flagship measurement:

CP Violation

  • 2. Implementing a phased approach with rich physics, highlighting:

The IsoDAR sterile neutrino program (Phase II)

A two-part talk:

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}

terms depending on mass splittings

}

terms depending on mixing angles We want to see if δ is nonzero

in a vacuum…

Oscillations at

e

ν ν μ →

2 13

~ 2 m L E Δ π Are Sensitive to δCP

( ) ( )

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}

terms depending on mass splittings

}

terms depending on mixing angles We want to see if δ is nonzero

in a vacuum…

Use L/E Dependence Of to Extract δCP

) (

e

P ν ν μ →

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The DAEδALUS Approach To Appearance: Multiple neutrino sources at different baselines Single neutrino detector The Traditional Approach To Appearance: Single neutrino source Multiple neutrino detectors at different baselines

e

ν

( )

e

ν

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  • Osc. maximum

Constrains rise

  • f probability

wave Constrains Initial flux

δ = π/2 δ = 0

Single Ultra-large Detector With Free Protons as IBD (νe + p e+ + n) Targets (Oil or Water)

Near Neutrino Source Mid-distance Neutrino Source Far Neutrino Source

_

Distance

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νe νμ νμ

The DAEδALUS Neutrino Source π+ decay-at-rest (DAR) beam:

p + C → Shape driven by nature! Only the normalization varies from beam to beam A great place to search for νμ νe

_ _

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  • Osc. maximum

at ~40 MeV Constrains rise

  • f probability

wave Constrains Initial flux

δ = π/2 δ = 0

νe νμ νμ

8 km 20 km Three Identical Beams

Near Neutrino Source Mid-distance Neutrino Source Far Neutrino Source

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Constrains Initial flux

You need to know which One is providing the beam. So they have to turn on/off. The duty factor is flexible, But beam-off time is needed.

1.5 km Accelerator 8 km Accelerators 20 km Accelerators

100μs 100μs 100μs 400μs 400μs Beam Off Beam Off

Near Neutrino Source Mid-distance Neutrino Source Far Neutrino Source

  • Osc. maximum

Constrains rise

  • f probability

wave

100μs 100μs 100μs 400μs 400μs 100μs 100μs 100μs 400μs 400μs

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Measurement strategy:

Using the near neutrino source measure absolute flux normalization with νe-e events to ~1%, Also, measure the νeC event rate. At far and mid-distance neutrino source, Compare predicted to measured νeC event rates to get the relative flux normalizations between 3 sites For all three neutrino sources, given the known flux, fit for the νμ → νe signal with δ as a free parameter

_ _

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The result is a decay-at-rest-flux That can be used for νμ νe searches Primary Cyclotron

(Separated sector, super-conducting)

Injector Cyclotron

(Compact, resistive)

Target/shielding We use multiple “Accelerator Units” to produce our DAR beam, Constructed out of Cyclotrons, Which accelerate H2 to 800 MeV

_ _

e- p p

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Submitted to NIM

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Coverage of CP violation parameter at LENA, 10 years Where can DAEδALUS run?

LENA is an outstanding possibility!

3σ evidence for CP violation This gets even better if it can be played against a conventional beam!

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  • 1. The experimental design for the flagship measurement:

CP Violation

  • 2. Implementing a phased approach with rich physics, highlighting:

The IsoDAR sterile neutrino program (Phase II)

A two-part talk:

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Ion source Ion source Injector Cyclotron Superconducting Ring Cyclotron Superconducting Ring Cyclotron Target/ Dump Target/ Dump Ion source Ion source Superconducting Ring Cyclotron Target/ Dump Target/ Dump Ion source Ion source Superconducting Ring Cyclotron Target/ Dump Target/ Dump

Far Site (20 km) DAEδALUS Near Site Mid Site (8 km)

Injector Cyclotron Injector Cyclotron Injector Cyclotron Injector Cyclotron Injector Cyclotron

Design Principle: “Plug-and-play”

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Ion source Injector Superconducting Ring Cyclotron Target/ Dump

Leads to an obvious multiphase development plan The “plug-and-play design” of what we are building

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Ion source Injector Superconducting Ring Cyclotron Target/ Dump

Phase I: The Ion Source

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The big issue… Space Charge Effects

If you inject a lot of charge here, it repels & beam “blows up” As radii get closer together, bunches at different radii interact To reduce the “space charge” at injection… we use H2

e- p p

2 protons per unit

  • f +1 charge

Two options for extraction:

  • Stripping foil
  • “Classical” Electrostatic Septum
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Ion Source:

By our collaborators at INFN Catania. Produces sufficient H2

+!

Beam to be characterized at Best Cyclotrons, Inc, Vancouver This winter (NSF funded)

Test results to be available by Cyclotrons’13 Conference, Sept 2013, Vancouver

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Open Issue: Lorentz stripping

Can induce unacceptable losses of H2

+ beam in the 800 MeV SRC

We are doing tests at Oakridge to study vibrational states from ion sources

Should be OK as long as high vibrational states are eliminated

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Ion source Injector Superconducting Ring Cyclotron Target/ Dump

So: some important questions remain for DAEδALUS, But we have a workable ion source for a Phase II

IsoDAR: A sterile neutrino experiment

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Ion source Injector Superconducting Ring Cyclotron Target/ Dump

So: some important questions remain for DAEδALUS, But we have a workable ion source for a Phase II

IsoDAR: A sterile neutrino experiment

Accepted for publication in PRL

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Base Design Injector:

60 MeV/n @ 5 mA of H2

+

Industry (IBA, BEST) produces ~1 mA p machines for isotope production:

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At 60 MeV/n, we can use this to make isotopes that beta-decay-at-rest…

IsoDAR

νe e+ p n In liquid scintillator

8Li 8Be + e- + νe

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1 kton LS detector 16.5 m

Use this low-energy pure νe source to search for sterile neutrinos!

_ Potential locations: KamLAND, SNO+, Borexino

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Ability to discriminate between models! 3+1 3+2 Outstanding sensitivity to sterile neutrinos à la the reactor neutrino anomaly…

…can be ruled out at > 5σ in 4 months of running!

(5 years of running)

95% C.L

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Along with sterile neutrino searches… Searches for new particles produced in dump Studies of antineutrino-electron scattering More ideas welcome! The science capability is outstanding. This is of interest to the medical isotope industry! This moves DAEδALUS forward!

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Ion source Base Design Injector Superconducting Ring Cyclotron Target/ Dump

Phases III and IV Establish the “standard” system And the the high-power system

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30 Phase III: SRC & Target/Dump; Near Accelerator Physics Program

Ion source Ion source Injector Cyclotron Superconducting Ring Cyclotron Superconducting Ring Cyclotron Target/ Dump Target/ Dump

DAEδALUS Near Site Mid Site (8 km)

Injector Cyclotron

Many exciting possibilities for a near accelerator physics program:

  • Short-baseline neutrino oscillation waves in ultra-large liquid scintillator detectors

Agarwalla, S. et. al. JHEP 12 (2011), 85

  • Coherent neutrino scattering in dark matter detectors

Anderson A., et. al. Phys. Rev. D 84, 013008 (2011)

  • Active-to-sterile neutrino oscillations with neutral current coherent neutrino scattering

Anderson, A. et. al. Phys. Rev. D 86, 013004 (2012)

  • Measurement of the weak mixing angle with neutrino-electron scattering at low energy

Agarwalla, S. and P. Huber JHEP 8 (2011), 59

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31 Phase III: SRC & Target/Dump; Near Accelerator Physics Program Phase IV: Modifications to SRC for high-power running at mid & far sites; CP violation Program

Ion source Ion source Injector Cyclotron Superconducting Ring Cyclotron Superconducting Ring Cyclotron Target/ Dump Target/ Dump Ion source Ion source Superconducting Ring Cyclotron Target/ Dump Target/ Dump Ion source Ion source Superconducting Ring Cyclotron Target/ Dump Target/ Dump

Far Site (20 km) DAEδALUS Near Site Mid Site (8 km)

Injector Cyclotron Injector Cyclotron Injector Cyclotron Injector Cyclotron Injector Cyclotron

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Summary…

Ion source Injector Superconducting Ring Cyclotron Target/ Dump

Existing Prototype, Tests Funded & Ongoing. Advanced Design, Proposing A physics Program: IsoDAR 1st Engineering Design soon to undergo external review Least Advanced, But based On past designs

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DAEδALUS

Conclusions Is… A phased program with strong physics along the way (especially the IsoDAR sterile neutrino search!) Being brought to you by an international collaboration

  • f accelerator and particle physicists,

with input from Industry

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Other Slides

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carbon Light target embedded in a heavy target p π+ μ+ p π− Also, no upstream targets!!! We will use 1 MW targets (we can use multiple targets) Design is well understood from past DAR experiments…

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Our proposed 800 MeV cyclotron is very similar to the existing Riken, Japan, cyclotron: Our first engineering design from MIT-PFSC Technology and Engineering Division… …will be available this autumn

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Some other useful articles (beyond those already highlighted)…

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What proton energy is required? There is a “Delta plateau” where you can trade energy for current to get the same rate of ν/MW “Delta Plateau” <600 MeV too little π+ production >1500 MeV energy goes into producing other particles besides π+ at a significant level proton energy (MeV)

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Beam envelope, No energy spread, 1% spread

Design work By A. Calanna

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We use an “isochronous cyclotron” design (magnetic field changes with radius) Allows multi-bunch acceleration

To produce the 800 MeV protons, we use Cyclotrons:

  • Inexpensive,
  • Practical below ~1 GeV
  • Good if you don’t need short timing structure
  • Typically single energy
  • Taps into existing industry
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The most challenging aspect: The Superconducting Ring Cyclotron Original design For ADS/thorium reactor applications, see web for our talk at