Elena

ELENA ( E xtra L ow EN ergy A ntiproton ring) is a storage ring at the CERN international research center for slowing down and cooling antiproton beams.

Elena
General view of the ring
Type of	Storage device
Appointment	Antimatter experiments
A country	France
Laboratory	CERN
Years of work	since 2016
Technical specifications
Particles	antiprotons , protons, H ions -
Energy	5.3 MeV - 100 KeV
Perimeter / length	30.4 m
Betatron frequencies	2.35, 1.45
Emittans	4 π mm mm
The number of clots	fourteen
The number of particles in the bunch	3 × 10 7
Geographical coordinates

A beam of antiprotons with a kinetic energy of 5.3 MeV is injected into the ELENA ring from the AD ( Antiproton Decelerator ) storage ring, then it is slowed down in the usual synchrotron mode, while the transverse emittance is restrained by electron cooling . The perimeter of the ring 30.4 m is 1/6 of the perimeter of AD. The release of a delayed beam is assumed with an energy of 100 keV. ELENA was created in order to increase the production efficiency of cold antiprotons that are used in experiments with traps ( ATHENA , ASACUSA , ATRAP ). Prior to this, the antiproton beam was slowed down by passing through the foil, while the efficiency of the passage of particles did not exceed 0.3% ^[1] . Using a new retarder ring, it should increase by 1-2 orders of magnitude.

There are two injectors, proton beams and H ^- ions on the ring for start-up and commissioning. The first beam was captured in November 2016. The first antiprotons were captured in August 2017 ^[2] .