Manipulation and transport of pfor an efficient production of H atoms

M. Tajima1,2, N. Kuroda1, P. Dupré2, M. Leali3, Y. Nagata2,4,T. Matsudate1, V. Mascagna3, B. Radics2, L. Venturelli3,

H. Breuker5, H. Higaki6, Y. Kanai2, E. Lodi Rizzini3, Y. Matsuda1,S. Ulmer7, and Y. Yamazaki2

1 The university of Tokyo, 2 Atomic Physics Research Unit, RIKEN, 3 University of Brescia, 4 Tokyo University of Agriculture and Technology,5 CERN, 6 Hiroshima University, 7 Ulmer Initiative Research Unit, RIKEN

7 March 2016 (LEAP2016)

Contents

• Direct injection

• H beam in 2012

• Transport of p

• Extraction of p

• H production rate

• Summary

Direct injection methodIn our setup, p are accumulated, cooled, and radially compressed in MUSASHI trap.

ADMUSASHI( p trap)

Direct injection methodIn our setup, p are accumulated, cooled, and radially compressed in MUSASHI trap.

ADMUSASHI( p trap)

CUSPtrap

Then p are injected into pre-loaded e+ in cusp trap to produce H.

Direct injection methodIn our setup, p are accumulated, cooled, and radially compressed in MUSASHI trap.

ADMUSASHI( p trap)

CUSPtrap

Then p are injected into pre-loaded e+ in cusp trap to produce H.

Direct injection methodIn our setup, p are accumulated, cooled, and radially compressed in MUSASHI trap.

ADMUSASHI( p trap)

CUSPtrap

Then p are injected into pre-loaded e+ in cusp trap to produce H.

In this scheme,a temperature of Hdepends onthe relative energyof p comparedto that of e+.

H beam in 2012

In 2012, we succeeded in detecting H beam at 2.7m downstream of the mixing region in cusp trap.

N. Kuroda et al. Nat. Commun. 5:3089 (2014)

H beam in 2012

In 2012, we succeeded in detecting H beam at 2.7m downstream of the mixing region in cusp trap.

N. Kuroda et al. Nat. Commun. 5:3089 (2014)

H beam in 2012

In 2012, we succeeded in detecting H beam at 2.7m downstream of the mixing region in cusp trap.

N. Kuroda et al. Nat. Commun. 5:3089 (2014)

H production reached

its peak about 20s after

the mixing of p and e+

H beam in 2012

In 2012, we succeeded in detecting H beam at 2.7m downstream of the mixing region in cusp trap.

N. Kuroda et al. Nat. Commun. 5:3089 (2014)

H production reached

its peak about 20s after

the mixing of p and e+

Possible reason:

e+ were heated up by 𝐩

The axial energy spread of p at CUSP in 2012

catchingpulse

p

The axial energy spread of p at CUSP in 2012

100 240X [V]

# o

f tr

app

ed p

[a.u

.]

catchingpulse

X

The axial energy spread of p at CUSP in 2012

100 240X [V]

# o

f tr

app

ed p

[a.u

.]

catchingpulse

XThe axial energy spread of 𝐩 at CUSP

was unexpectedly large.

Disadvantage of large axial energy spread of pat CUSP in direct injection scheme

p

Mix as many 𝐩 as possible → hot 𝐇

Disadvantage of large axial energy spread of pat CUSP in direct injection scheme

Avoid too much heating of e+

→ Less 𝐇

p

The axial energy spread of p at CUSP in 2012

p

Desirable

What is the reason of the large axial energy spread of p at cusp?

Calculated trajectory of p

Injection at 150eVw/ lens & DC coils

Calculated trajectory of p (initial r=0.4, 0.8, 1.2, 1.6mm)

Calculated trajectory of p

Injection at 150eVw/ lens & DC coils

B field line

Calculated trajectory of p

Injection at 150eVw/ lens & DC coils

Calculated trajectory of p

Injection at 150eVw/ lens & DC coils

Far from adiabatic p do not follow B field line

The axial energy spread of p at CUSP in 2012

p

Desirable

We think the reason of the large axial energy spread of p at cusp is non-adiabatic transport. → Realize a transport of p

following B field line more adiabatically.

Calculated trajectory of p

Injection at 150eVw/o lens, w/ DC coils

Calculated trajectory of p

Injection at 150eVw/o lens, w/ DC coils

Still far from adiabatic.Low transport efficiency .

Calculated trajectory of p

Injection at 20eVw/ DC coils (15→50A)

Calculated trajectory of p

Injection at 20eVw/ DC coils (15→50A)

B field line diverges at the exit of MUSASHI→ Low transport efficiency

Calculated trajectory of p

Injection at 20eVw/ DC coils (50A) & a pulse coil

Calculated trajectory of p

Injection at 20eVw/ DC coils (50A) & a pulse coil

p follows B field line.

Calculated trajectory of p

Injection at 20eVw/ DC coils (50A) & a pulse coil

p follows B field line.

This is the way to transport 𝐩 in 2015.

Initial axial energy spread of pextracted from MUSASHI

Charged π from annihilated p were detected by a plastic scintillator.

Scintillator

MUSASHItrap

CUSPtrap

1.5m

Scintillator

MUSASHItrap

CUSPtrap

Initial axial energy spread of pextracted from MUSASHI

2.1 m

Scintillator

MUSASHItrap

CUSPtrap

Initial axial energy spread of pextracted from MUSASHI

1.5m 2.1 m

Scintillator

MUSASHItrap

CUSPtrap

Initial axial energy spread of pextracted from MUSASHI

Extractionfrom MUSASHI

1.5m 2.1 m

Scintillator

MUSASHItrap

CUSPtrap

Initial axial energy spread of pextracted from MUSASHI

1.5 2.1 m

Scintillator

MUSASHItrap

CUSPtrap

Extractionfrom MUSASHI

Initial axial energy spread of pextracted from MUSASHI

H production rate

■: in 2015

●: in 2012

H production rateWe succeeded in a production of H at higher rate just after the mixing started. → Colder H which is desirable for a spectroscopy.

S/N ratio of the H beam detector should be improved.

Zoom ofthe first 1s

H production rate

Another peak was also observed.Some of the e+ were still heated up.

→ The transport should be improved further.

Further improvement

With increased current of DC transport coils by a factor of 3, the axial energy spread of p at cusp becomes smaller.

Calculationassuminga p cloud of 5000K in MUSASHI.

PulseCoil

MUSASHItrap

CUSPtrap

DC transportcoils (150A)

Summary

• For an efficient production of H using the direct injection scheme, we developed the way to extract and transport p at 20 eV, more adiabatically than the previous scheme in 2012.

• We observed a higher production rate of H just after a mixing started. We believe colder H which is desirable for a spectroscopy were produced.

• Further improvement will be realized by a modification of transport coils and tests are ongoing.

Thank you very much for your attention!