CERN Accelerating science

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.

Today a paper was published in Phys. Rev. Lett.in which a collaboration of researchers from Max Planck Institute for Nuclear Physics, Heidelberg, Germany and Members of BASE/RIKEN's Ulmer Fundamental Symmetries Lab report on a three-fold improved measurement of the proton mass in natural units.

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.

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.

Today our article on an improved measurement of the magnetic moment of the antiproton, with a fractional precision of 0.8 parts in a million, was published in Nature Communications. This is, so far, the culmination point of 10 years of dedicated work on proton and antiproton magnetic moment measurements.

Our colleagues from the ALPHA collaboration just published an article on the Observation of the 1S/2S Transition in Trapped Antihydrogen.
We congratulate to this fantastic result!!!

See also the Nature-News and Views-Point

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.

Our article "Highly sensitive superconducting circuits at ∼700 kHz with tunable quality factors for image-current detection of single trapped antiprotons" has been published in Review of Scientific Instruments. There we describe highly sensitive image-current detection systems based on superconducting toroidal coils and ultra-low noise amplifiers for non-destructive measurements of the axial frequencies (550–800 kHz) of single antiprotons stored in the BASE multi-Penning-trap system.

A crucuial device in the BASE multi-Penning trap system is a reservoir trap for antiprotons. This trap is loaded with a cloud of antiprotons provided by CERN's antiproton decelerator and methods were developed to extract single particles from this reservoir and to supply them to our high precision measurement traps. This allows BASE to continuously perform experiments with antiprotons, independent from accelerator maintenance and shutdown cycles.

A short overview-article on BASE has been released in CERN's EP-newsletter.