First explicit measurement of heating rates in a cryogenic Penning trap

Submitted by sulmer on Mon, 01/28/2019 - 17:20

Today we report on the first explicit measurement of cyclotron quantum heating rates in a cryogenic Penning trap. We demonstrate that the scaled electric field noise in our spin-analysis trap, an essential instrument in our 1.5 p.p.b. measurement of the antiproton magnetic moment, is much lower than observed in other ion trap experiments. It corresponds to a heating rate below 0.1 quanta per hour and a radial energy stability on the peV/s-level.

11-fold improved measurement of the proton magnetic moment

Submitted by sulmer on Thu, 11/23/2017 - 22:34

Today we report in SCIENCE on a new measurement of the proton magnetic moment in units of the nuclear magneton. The updated value gp/2=2.792 847 344 62 (82) is consistent with our previous best measurement, but improves the precision by a factor of 11. The measurement was carried out using an optimized double Penning trap technique. Compared to our 2014 measurement, a trap with higher magnetic field stability and homogeneity was implemented.

Improved limit on directly measured antiproton lifetime

Submitted by sulmer on Thu, 08/31/2017 - 18:26

In the entire 2016 antiproton run BASE was operated with particles trapped in 2015. The particles were suspended from the unique reservoir trap to the measurement traps on request, apart from dispensing single antiprotons to the other traps, not a single antiproton was lost in an integrated observation time of in total 405 days.

RIKEN Opens Fundamental Symmetries Laboratory

Submitted by sulmer on Mon, 05/01/2017 - 12:51

The japanese research institute RIKEN will continue its strong support of the work of the BASE collaboration. To this end the new, dedicated "fundamental symmetries laboratory (FSL)" has been opened. The major research goal of FSL will be to push the limits in ultra-precise comparisons of the fundamental properties of protons and antiprotons.

First Observation of Single Antiproton Spin Transitions

Submitted by sulmer on Tue, 03/21/2017 - 10:21

Today we have published a paper in Phys. Lett. B, in which we report on the detection of individual spin quantum transitions of a single trapped antiproton in a Penning trap. The spin state determination is based on the unambiguous detection of axial frequency shifts which are induced by the spin transition in presence of a magnetic bottle. We have achieved a detection fidelity of 92.6 % and demonstrated spin state initialization with 99.9% fideltiy.

First circulating beam in ELENA

Submitted by sulmer on Sat, 12/17/2016 - 18:58

The construction of ELENA, the Extra Low Energy Antiproton Ring, which is dedicated to slow-down the 5.3 MeV AD antiprotons to keV energies has been finished and is entering the commissioning phase. In a recent AD users meeting the ELENA team around project coordinator Christian Carli has reported on first circulating beam, CONGRATULATIONS! For more information read the CERN courier article.