Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Progress of antihydrogen beam productionwith the double cusp trap

Yugo Nagata

Department of applied physics, Tokyo University of Agriculture and TechnologyAtomic Physics Research Unit, RIKEN

March 7th, 2016 LEAP2016

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Y. Nagata1,2, P. Dupre2, S. Van Gorp2, N. Kuroda3, C. Malbrunot4,5,D.J. Murtagh2, B. Radics2, C. Sauerzopf5, M. Tajima3,2, M. Diermaier5

C. Kaga6, B. Kolbinger4, M. Leali7, E. Lodi Rizzini7, V. Mascagna7,O. Massiczek5, T. Matsudate3, H. A. Torii3, B. Wuenschek5, J. Zmeskal5,

H. Breuker4, Y. Kanai2, H. Higaki6, Y. Matsuda3, S. Ulmer8,L. Venturelli7, E. Widmann5, Y. Yamazaki2,

1Department of Applied Physics, Tokyo University of Agriculture and Technology2Atomic physics research unit, RIKEN, Wako, Saitama 351-0198, Japan

3Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan4CERN, CH-1211, Geneva 23, Switzerland

5Stefan Meyer Institute for Subatomic Physics, Boltzmanngasse 3,1090 Vienna, Austria6Graduate School of Advanced Sciences of Matter, Hiroshima University,1-3-1 Kagamiyama, Higashi-Hiroshima,

Hiroshima 739-8530 Japan7Dipartimento di Ingegneria dell’ Informazione, Universit a di Brescia & Istituto Nazionale di Fisica Nucleare, Gruppo

Collegato di Brescia, 25133 Brescia, Italy8Ulmer Initiative Research Unit, RIKEN, Wako, Saitama 351-0198, Japan

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Table of contents

1 IntroductionMotivationMicrowave hyperfine spectroscopy of H̄ in ASACUSA

2 Double cusp magnetSuperconducting double cusp magnet

3 H̄ synthesisH̄ synthesis

4 H̄ beams and spectroscopy lineH̄ beam detector

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Table of contents

1 IntroductionMotivationMicrowave hyperfine spectroscopy of H̄ in ASACUSA

2 Double cusp magnetSuperconducting double cusp magnet

3 H̄ synthesisH̄ synthesis

4 H̄ beams and spectroscopy lineH̄ beam detector

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Motivation

CPT symmetry

• CPT is a fundamental discrete symmetry in StandardModel.

Phenomena which can not be explained in Standard Model• Neutrino oscillation.

• Dark matter and dark energy.

• Standard Model must be extended.→ CPT symmetry is worth testing.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

CPT test using Antihydrogen and Hydrogen

• CPT theorem tells matter and antimatter are symmetric.For example, mass, charge and spectroscopic properties.→ CPT symmetry can be tested by comparing matter andantimatter

• Spectroscopic properties of Hydrogen are well known inhigh precision.

Our target is antihydrogen.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Standard Model Extension (SME)

The system of antihydrogen is expressed by

( iγµDµ − me

Dirac

)ψ = 0

where，Dµ = i∂µ − qAµ．

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Standard Model Extension (SME)

Introduce local lorenz and CPT violation factor into StandardModel.

( iγµDµ − me

Dirac

−aeµγ

µ − beµγ5γ

µ

CPT & Lorentz violation

−12

Heµνσ

µν + iceµνγ

µDν + ideµνγ5γ

µDν

Lorentz violation

)ψ = 0

where D = i∂µ − qAµ．D. Colladay and V. A. Kostelecky, PRD 55 (1997) 6760.

R. Bluhm, V. A. Kostelecky and N. Russell, PRL 82 (1999) 2254.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Standard Model Extension (SME)

( iγµDµ − me

Dirac

−aeµγ

µ − beµγ5γ

µ

CPT & Lorentz violation

−12

Heµνσ

µν + iceµνγ

µDν + ideµνγ5γ

µDν

Lorentz violation

)ψ = 0

• 1S-2S and Hyperfine transitions of H̄ are sensitive to CPTviolation.

• 1S-2S and hyperfine are complementary measurement.

• Energy levels are affected by these factors.→ Absolute precision is important.

D. Colladay and V. A. Kostelecky, PRD 55 (1997) 6760.R. Bluhm, V. A. Kostelecky and N. Russell, PRL 82 (1999) 2254.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Comparison of hydrogen spectroscopy with K0 CPT test.

1S-2S Hyperfine mK0 − mK̄0

Frquency 2466 THz 1.4 GHz1.4× 1014 GHz(497 MeV/c2)

Relativeprecision 4.5× 10−15 7.0× 10−13 6× 10−19

Absoluteprecision 11 Hz 1.0 mHz 72 kHz

The hyperfine splitting of antihydrogen is sensitive consideringthe absolute precision.We decided to measure the hyperfine transition ofantihydrogen.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

How to measure the hyperfine frequency ?

• Low field seeking(LFS) state and high field seeking(HFS)state

B[T]

F

requen

cy [

GH

z]

LFS

HFS

e+ p

(F, M)=(1, -1)

(F, M)=(1, 0)

(F, M)=(1, 1)

(F, M)=(0, 0)

2.0

1.5

1.0

0.5

0.0

-0.5

-1.0

-1.5

-2.00.00 0.02 0.04 0.06 0.08 0.10

ϕ = −µ · B

F = −∇ϕ

If µ is a constant,

F = µ∇|B|

H̄ atoms can be manipulated by magnetic field gradient.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

How to measure the hyperfine frequency ?

Beam source Spin polarizer

(Magnet)

Microwave

CavitySpin state

analyzer (Magnet)

Detector

LFS

HFS

LFS

HFS

Unpolarized beam

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

How to measure the hyperfine frequency ?

Single Cusp trapH atoms

Anti-Helmholtz coils

Multi-ring

electrodes

Magnetic field line

Beam source Spin polarizer

(Magnet)

Microwave

CavitySpin state

analyzer (Magnet)

Detector

LFS

HFS

LFS

HFS

Unpolarized beam

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Beam focusing by single cusp magnet

-0.1-0.05

00.05

0.1

-0.2

0

0.2

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5Antihydrogen

Beam axis z [m]r [m]

|B| [

T]

Beam axis z [m]

r [m]F=µ∇|B|

F

• |B| is harmonic radially.→ Atomic beam can focus, if vz of atoms are same.

Y. Nagata and Y. Yamazaki, New J. Phys. 16 (2014) 083026. 14 / 34

Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

How to measure the hyperfine frequency ?

Single Cusp trap

H atoms

Anti-Helmholtz coils

Multi-ring

electrodes

CavitySextupole

magnet

H beam

Detector

H beam polarizedLow field seeking states

Ground state

High field seeking states

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Antihydrogen atomic beam production in 2012

In 2012, we suceeded in producing H̄ atomic beamsof 60 H̄ / hour.

N. Kuroda, S. Ulmer, D.J. Murtagh, S. Van Gorp, Y. Nagata, et al., Nat. Commun., 5,(2014) 3089.

Improvement from 2012 to 2016• New superconducting magnet was developed.

• ASACUSA MicroMEAGS tracker was developed.

• Antiproton injection method was studied.

• New H̄ beam detector was developed.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Table of contents

1 IntroductionMotivationMicrowave hyperfine spectroscopy of H̄ in ASACUSA

2 Double cusp magnetSuperconducting double cusp magnet

3 H̄ synthesisH̄ synthesis

4 H̄ beams and spectroscopy lineH̄ beam detector

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Microwave hyperfine spectroscopy of H̄

CavitySextupole

magnet

H beam

Detector

H atoms

Superconducting double cusp magnet

(two sets of anti-Helmholtz coils)

MRE H beam polarizedLow field seeking states

Ground stateHigh field seeking states

Single Cusp trap

Double Cusp trap

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Beam focusing by double cusp magnet

-0.5

0

0.5 -0.2-0.15

-0.1-0.05

00.05

0.10.15

0

1

2

3

4

5

6 Antihydrogen

Beam axis z [m]

r [m]

|B| [

T]

Beam axis z [m]

r [m]F=µ∇|B|

F

• |B| is harmonic radially.→ Atomic beam can be focused by double cuspmagnet.

Y. Nagata and Y. Yamazaki, New J. Phys. 16 (2014) 083026.19 / 34

Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Table of contents

1 IntroductionMotivationMicrowave hyperfine spectroscopy of H̄ in ASACUSA

2 Double cusp magnetSuperconducting double cusp magnet

3 H̄ synthesisH̄ synthesis

4 H̄ beams and spectroscopy lineH̄ beam detector

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Experimental setup

Positron accumulator

MUSASHI trap

(antiproton trap)

Double cusp trap

Na source

Microwave cavity

Sextupole magnet

Antihydrogen beam

detector

0 5431 2 [m]

22

P from Antiproton decelerator (CERN)

e+H

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Experimental setup (Double cusp trap)

Double cusp magnet ASACUSA micromegas

tracker (AMT)

p

e+ Multi-ring electrodes

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Experimental setup (ASACUSA Micromegas Tracker, AMT)

Size: radius =78.5mm, length=400mm

radius =88.5mm, length=400mm

Strips: 288 axial and 448 circumferential

Resolution: 250µmPlastic scintillators

MicroMEGAS

4

MRE

MicroMEGAS

Plastic scintillators

• MicroMEGAS measures the hit positions of particles in eachlayer.

• Charged particle tracks are reconstructed

• Annihilation points of p̄ or H̄ are determined from those tracks.

P-20, B. Radics et al. 25 / 34

Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

H̄ synthesis in the double cusp trap

z [m]0.50-0.1-0.2-0.3 0.3 0.40.20.1-0.4

300

0

-100

-200

-300

100

200

Volt

age

[V]

-0.5

1

32

0-1

-3-2

Mag

net

ic f

ield

[T

]

Multi-ring electrodes

Mixing region

Field ionization well

e+

p

001- 0010[ms]

0 < t < 20 s

120

80

40

150eV p injection

P-18, N. Kuroda et al.Next talk by Tajima-san, P-19, M. Tajima et al.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

H̄ synthesis in the double cusp trap

z [m]0.50-0.1-0.2-0.3 0.3 0.40.20.1-0.4

300

0

-100

-200

-300

100

200

Volt

age

[V]

-0.5

1

32

0-1

-3-2

Mag

net

ic f

ield

[T

]

Multi-ring electrodes

Mixing region

Field ionization well

e+

p

001- 0010[ms]

0 < t < 20 s

120

80

40

150eV p injection

Antiproton injection is key technique for production of cold antihydrogen atoms in our experimentNext talk by Tajima-san

P-18, N. Kuroda et al.Next talk by Tajima-san, P-19, M. Tajima et al.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Table of contents

1 IntroductionMotivationMicrowave hyperfine spectroscopy of H̄ in ASACUSA

2 Double cusp magnetSuperconducting double cusp magnet

3 H̄ synthesisH̄ synthesis

4 H̄ beams and spectroscopy lineH̄ beam detector

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Experimental setup

Positron accumulator

MUSASHI trap

Double cusp trap

Na source

Microwave cavity

Sextupole magnet

Antihydrogen beam

detector

0 5431 2 [m]

22

Field ionizer

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Experimental setup

Positron accumulator

MUSASHI trap

Double cusp trap

Na source

Microwave cavity

Sextupole magnet

Antihydrogen beam

detector

0 5431 2 [m]

22

Field ionizer

Reference experiment is going on using hydrogen atoms

for high precision measurement.

Talk by M. Diermaier on Thursday.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

H̄ beam detector

H

Hodoscope

BGO crystal

H̄ beam detector consists of 2D BGO detector and hodoscope.

P-23 BGO , Y. Nagata et al.P-24 Hodoscope, B. Kolbinger et al.

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Introduction Double cusp magnet H̄ synthesis H̄ beams and spectroscopy line

Summary

• The double cusp trap was developed and suceeded inproducing H̄ atoms.The double cusp magnet increase the LFS H̄ beams than singlecusp.

• AMT was developed.

• Direct injection method for 20 eV antiprotons aredeveloping (next talk).

• The H̄ beam detector was developed.

We are ready to measure the hyperfine splitting of H̄ atoms.

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