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GABRIELSE RESEARCH GROUP

Professor Gerald Gabrielse
Harvard Physics Department

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People Opportunities for Graduate Students and Postdocs Trivia: Angels and Demons
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Printable Narrative on Group Research Trivia: Jim Carey and Conan O'Brien

Current Research Projects (overview)

Lepton Magnetic Moments -- one apparatus, many results (below)

Supported by NSF AMO
 
most accurate measurements of g/2 and α

 

S. Fogwell,
J. Dorr,
G. Gabrielse,
(many earlier
contributions
)

ATRAP Antihydrogen Studies

Supported by NSF and AFOSR
 
Penning-Ioffe trap for antihydrogen
Dr. J. Wrubel,
P. Larochelle,
R. McConnell,
S. Kolthammer,
P. Richerme,
G. Gabrielse,
and collaborators

Proton and Antiproton Magnetic Moments*,**

Supported by NSF and AFOSR
 
first signal from a self-excited proton oscillator
  • Goal 1: Nondestructive observations of the spin flips of a single trapped proton
  • Goal 2: Measurement of a proton spin resonance using quantum jump spectroscopy
  • Goal 3: Determine the magnetic moment of the proton from measured spin and cyclotron frequencies
  • Goal 4: Load antiprotons into the trap and duplicate goals 1 to 3 with a single trapped antiproton
  • Goal 5: Compare the antiproton and proton magnetic moments a million or more times more accurately
N. Guise,
J. DiSciacca,
G. Gabrielse

Why Does Sideband Mass Spectroscopy Work?

Supported by NSF, AFOSR and the Humboldt Foundation
 

What "deeper magic" makes the sideband frequency, ω+ + ω-, be a good approximation to the cyclotron frequency?


G. Gabrielse

Investigation of a One-Electron Qubit

   
 
planar Penning trap
  • Goal 1: To observe one electron suspended within a planar trap chip
  • Goal 2: To demonstrate a one-electron qubit for the first time
  • Goal 3: To couple one-electron qubits
  • Goal 4: To investigate a coupled array of one-electron qubits

 

J. Goldman,
P. Hess,
G. Gabrielse,

ACME Search for the Electric Dipole Moment of an Electron

   
 

  • Use ThO molecule
  • Goal is a significantly improved electron EDM measurement or limit on a 5 year time scale
Y. Gurevich,
B. Spaun,
G. Gabrielse,
(and collaborators
from the DeMille
and Doyle groups)


Some Completed Projects (overview)

Comparing Q/M of the Antiproton and Proton to 9 parts in 1011

Was supported by NSF AMO and AFOSR
 
improving antiproton q/m by factor of almost a million
  • Most stringent test of CPT invariance with a baryon system
  • Nearly a million times more precise than previous CPT tests with baryons
  • Series of three measurements with increasing accuracy
 

Methods to Slow, Trap, Electron-Cool, and Accumulate Cold Antiprotons

Was supported by NSF AMO and AFOSR
 
first antiproton trap
  • Developed by the Gabrielse group and TRAP collaborators
  • Used to get cold antiprotons for Q/M measurements
  • Makes possible all cold antihydrogen experiments

 

  • First capture of antiprotons in a Penning trap
  • First electron-cooling of trapped antiprotons
  • Stacking antiprotons

  • Brown-Gabrielse Invariance Theorem:

     

    Makes possible many of the most precise measurements in particle, atomic, and nuclear physics

     

    • Makes possible the most accurate measurements of magnetic moments
    • Makes possible the most accurate ion mass spectroscopy
    • Makes possible the most accurate nuclear mass spectrometry

    Useful New Designs for Penning Traps

    Was supported by NSF AMO and AFOSR
     
    cylindrical Penning trap
     

    Superconducting Solenoid that Shields Magnetic Field Fluctuations

    Was supported by NSF AMO, AFOSR and NIST
     

    • Cancels by a factor of 250 or more any change in the external magnet field
    • A flux change in the solenoid produces a current, that produces a field, that cancels the field change at the center of the system
    • No active electronics
    • Made it possible to do antiproton Q/M measurements not far from cycling LEAR and PS magnets
    • Allows MRI imaging machines to be located nearer to elevators, etc.
    • Used for stable ICR mass spectrometry (e.g. to analyze pharmaceuticals)

    Theory of One Particle in a Penning Trap

    Was supported by DOE and NSF
     

    • The often-cited basic review of the properties of a charged particle in a Penning trap