ATRAP on the way to trapped Antihydrogen

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ATRAP on the way to trapped Antihydrogen
D. Grzonka for the ATRAP Collaboration

Harvard University
G. Gabrielse, N. Guise, P. Larochelle, D. Le
Sage, A. Speck
Penning trap for p and e Ioffe trap for
Antihydrogen
IKP FZ-Jülich
charge particle detection, ? detection, Ioffe trap
W. Oelert, F. Goldenbaum, D. Grzonka, T.
Sefzick, Z. Zhang
MPI für Quantenoptik Garching
T. W. Hänsch, H. Pittner, J. Walz
Laser spectroscopy
E. Hessels, D. Comeau, C. Storry
York Univ. Toronto
PPAC, Cs charge exchange
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Antihydrogen studies at ATRAP
Antihydrogen production
Spectroscopy CPT test gravitational studies
Antihydrogen trapping

cold Antihydrogen ground state
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Why cold Antihydrogen
EB µB B
H trapping efficiency
µB 5.788 . 10-5 eV/T
k 8.62 . 10-5 eV/K
Trap depth µB/k 0.67 K/T
?B 1T
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Antihydrogen studies at ATRAP
Antihydrogen production
Spectroscopy CPT test gravitational studies
Antihydrogen trapping

cold Antihydrogen ground state
temperature measurement N-state
distribution cloud shapes (optimization)
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Hydrogen 1s 2s Spectroscopy
cold (5-7 K) H atomic beam two photon
excitation velocity measurement ? correct 2.
order doppler shift laser photon density
variation ? correct stark shift
2s
2p
(t 1.4 ns)
(t 0.12 s)
243 nm
243 nm
1s
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T4.2 K
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H Production and Detection (G. Gabrielse et al.,
PRL 89 (2002) 233401 , 213401)
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n - State Analysis
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n State Distribution
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Velocity Measurement
potential distribution in the trap
0
p
p
V / Volts
-20
ionization well
analysis well
-40
-60
-80
-100
-120
-140
z / cm
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Velocity Measurement
potential distribution in the trap
0
p
p
V / Volts
-20
ionization well
analysis well
-40
e
-60
-80
-100
-120
-140
z / cm
12
Velocity Measurement
potential distribution in the trap
0
p
p
V / Volts
-20
ionization well
analysis well
-40
-60
-80
-100
-120
-140
z / cm
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Velocity Measurement
( 2400 K )
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Further studies

• reduce temperature in
• nested Penning trap configuration
• varying drive strength
• varying potentials
• Laser induced transitions
• low N-state ? high N-state
• high N-state ? low N-state

no improvement !
no result, statistics too low !
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permanent quadrupol
permanent magnet
BGO
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Stability of electron clouds in Penning trap
surrounded by a permanent quadrupole
Preliminary
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Summary

• Nested Penning Trap
• routinely production of antihydrogen ? detailed
  studies possible
• determination of density and
• spatial distribution of e and p
• measurement of
• N-state distribution
• velocity measurement of H
• Studies towards antihydrogen trapping
• stable charged particle clouds in Penning trap
  with quadrupole field

( optimize H production )
( de-excitation to ground state )
( trapping of H )
design of Ioffee trap (superconducting magnet)