ATRAP Antihydrogen Collaboration

Long Term Goal: Precise laser or microwave spectroscopy of trapped antihydrogen
to make the most stringent lepton and baryon CPT tests

``When antihydrogen is formed in an ion trap, the neutral atoms will no longer be confined and will thus quickly strike the trap electrodes. Resulting annihilations of the positron and antiproton could be monitored. ..."

"... it is clear that the very low [antihydrogen production rate] will make ... experiments with antihydrogen to be very ... difficult. For me, the most attractive way ... would be to capture the antihydrogen in a neutral particle trap ... The objective would be to then study the properties of a small number of [antihydrogen] atoms confined in the neutral trap for a long time."

Gerald Gabrielse, 1986 Erice Lecture (shortly after first trapping of antiprotons), in Fundamental Symmetries, ed. by P. Bloch, et al., p. 59 (Plenum, NY, 1987)

ATRAP Simultaneously Loads Positrons and Antiprotons During a 100 Second Cycle


tick marks: 1 meter

Positron accumulator		Cold positrons and
accumulates positrons		cold antiprotons are accumulated
from a ²²Na source		in Penning traps located
		within a 1-3 Tesla solenoid
		(below left)


		Antiprotons come from
		the CERN Antiproton
time axis		Decelerator (AD)
		storage ring

0 seconds
antiprotons load

30 seconds
positrons load

70 seconds
more positrons load

100 seconds
cycle starts over

scintillation
detectors

Anihydrogen is produced
within a Ioffe trap
by one of two methods
that ATRAP developed
(method 1, method 2,
traps for antihydrogen)

Solenoid and vacuum container for the traps

Inside view of Penning traps and Ioffe trap
rotated 90 degrees clockwise

ATRAP is a collaboration of the following groups:

Harvard University - Responsible for the Penning traps, integration of the experiment, particle trapping, hbar formation, and design/construction of the second generation Ioffe trap. Professor Gabrielse is the ATRAP spokesperson and coordinator.
Forschungszentrum Juelich - Responsible for the scintillating detectors and first generation Ioffe trap production.
York University - Responsible for the positron accumulator.
University of Mainz - Responsible for laser systems for spectroscopy and excitation of Cesium to Rydberg states.
MPQ collaborators - Joining in for antihydrogen spectroscopy
Rowland at Harvard collaborators - Laser de-excitation of antihydrogen.

Note: everyone at ATRAP helps out as needed on whatever part of the project needs help, so these divisions are often blurred

ATRAP Antihydrogen Collaboration

Gabrielse Group

Hessels and Storry Groups

Walz Group

Speck Group

Long Term Goal: Precise laser or microwave spectroscopy of trapped antihydrogen
to make the most stringent lepton and baryon CPT tests

ATRAP Simultaneously Loads Positrons and Antiprotons During a 100 Second Cycle

ATRAP is a collaboration of the following groups:

ATRAP Antihydrogen Collaboration

Gabrielse Group

Hessels and Storry Groups

Walz Group

Speck Group

Long Term Goal: Precise laser or microwave spectroscopy of trapped antihydrogen to make the most stringent lepton and baryon CPT tests

ATRAP Simultaneously Loads Positrons and Antiprotons During a 100 Second Cycle

ATRAP is a collaboration of the following groups:

Long Term Goal: Precise laser or microwave spectroscopy of trapped antihydrogen
to make the most stringent lepton and baryon CPT tests