Hannover 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
A: Fachverband Atomphysik
A 25: Precision Spectroscopy of Atoms and Ions III
A 25.4: Talk
Friday, March 12, 2010, 11:15–11:30, F 107
Application of electronic feedback to aproton stored in a cryogenic Penning trap — •Stefan Ulmer1,2,3, Klaus Blaum2,3, Holger Kracke1, Andreas Mooser1, Wolfgang Quint4, Cricia Rodegheri1, and Jochen Walz1 — 1Institut fürPhysik, Johannes Gutenberg-Universität Mainz, 55099 Mainz — 2Max-Planck-Institut für Kernphysik, 69117Heidelberg — 3Ruprecht-Karls-Universität, 69047Heidelberg — 4GSI Darmstadt, 64291 Darmstadt
This experiment aims at the high precision measurement
of the g-factor of the proton stored in a cryogenic Penning
trap. The comparison of this number to the g-factor of the
antiproton will give a stringent test of the CPT symmetry in the
baryonic sector. Both quantities will be determined by the
measurement of the particles eigenfrequencies in the Penning trap.
The axial frequency is measured with a highly sensitive
superconducting detector, including an electronic feedback loop. The
measured signal is fed back to the detector. Different aspects of
this technique are discussed. Using positive feedback the signal to
noise ratio increases. Thus, the axial frequency could be measured
within 20 seconds to a relative precision of 10−7. Furthermore
with the high signal to noise ratio a novel detection schematic
could be applied, which allows for the simultaneous measurement of
the three eigenfrequencies of the trapped particle. Using negative
feedback in combination with phase sensitive detection of the
particle a frequency difference of 200 mHz was resolved in a
2 s measuring cycle. This resolution is sufficient to observe the
effect of proton spin quantum jumps in the axial frequency.