ELENA: An Upgrade to the Antiproton Decelerator (original) (raw)

The antiproton decelerator: AD

Nuclear Instruments and …, 1997

In view of a possible future programme of physics with low-energy antiprotons, a simplified scheme for the provision of antiprotons at 100 MeV/c has been studied. It uses the present target area and the modified Antiproton Collector (AC) in its present location. In this report ...

Commissioning and first operation of the Antiproton Decelerator (AD)

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001

The Antiproton Decelerator (AD) is a simplified source of antiprotons which provides low energy antiprotons for experiments, replacing four machines : AC (Antiproton Collector), AA (Antiproton Accumulator), PS and LEAR (Low Energy Antiproton Ring), shutdown in 1996 . The former AC was modified to include decelera tion and electron cooling. The AD s tarted operation in July 2 000 and has since delivered cooled beam at 100 MeV/c (kinetic energy of 5.3 MeV) to 3 experiments (ASACUSA, ATH ENA and ATRAP) for 150 0 h. The flux (up to 2.5´105 pbars /s delivered in s hort pulses of 330 ns every 110 s) a nd the quality of the ejected beam a re not far from the des ign s pecifica tions. A linear RF Qua drupole Decelera tor (RFQD) was commis sioned in November 20 00 to pos t-decelera te the beam for ASACUSA from 5.3 MeV to about 15 keV. Problems encountered in converting the fix ed energy AC into a decelerating machine will be outlined, and the present status of the AD, including the performance of the cooling systems and the specia l diagnos tics to cope with beams of less than 107 pba rs, will be reviewed. Pos sible future developments will be sketched.

Confinement of a Large Number of Antiprotons and Production of an Ultraslow Antiproton Beam

Physical Review Letters, 2005

We have used a radio frequency quadrupole decelerator to decelerate antiprotons emerging from the CERN Antiproton Decelerator from MeV-to keV-scale energy, and collected five decelerated pulses in a multiring trap. Some 5 10 6 antiprotons were stacked in this way. Cooling of the trapped antiprotons by a simultaneously trapped electron plasma was studied nondestructively via shifts in plasma mode frequencies. We have also demonstrated the first step in extracting a 10-500 eV antiproton beam from the trap.

The Vacuum System of the Extra-Low Energy Antiproton Decelerator ELENA at CERN

2015

The Extra Low Energy Antiproton ring (ELENA) is a CERN project aiming at constructing a 30 m circumference synchrotron which will take antiprotons extracted at 5.3 MeV from the Antiproton Decelerator (AD), and further decelerate them down to 100 keV [1]. The ring will be equipped with two electrostatic (ES) pulsed extraction deflectors which will allow to deliver the low-energy, cooled antiproton beams to a number of experimental beamlines [2]. The total length of these transfer lines, equipped with ES optical elements is of the order of 100 m. From the vacuum point of view, machine physics issues related to rest-gas scattering and intrabeam scattering mandate a very low average pressure limit, calculated to be 4.0E-12 mbar [3,4]. The very compact ring and the beam-instrumentation installed on it, with many components placed inside of the vacuum system, and lack of space to install lumped pumps, has pushed us to design a pumping system based primarily on non-evaporable getter (NEG) ...

Beam measurement systems for the CERN antiproton decelerator (AD)

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)

The new, low-energy antiproton physics facility at CERN has been successfully commissioned and has been delivering decelerated antiprotons at 100 MeV/c since July 2000. The AD consists of one ring where the 3.5 GeV/c antiprotons produced from a production target are injected, rf manipulated, stochastically cooled, decelerated (with further stages involving additional stochastic and electron cooling and rf manipulation) and extracted at 100 MeV/c. While proton test beams of sufficient intensity could be used for certain procedures in AD commissioning, this was not possible for setting-up and routine operation. Hence, special diagnostics systems had to be developed to obtain the beam and accelerator characteristics using the weak antiproton beams of a few 7 10 particles at all momenta from 3.5 GeV/c down to 100 MeV/c. These include systems for position measurement, intensity, beam size measurements using transverse aperture limiters and scintillators and Schottky-based tools. This paper gives an overall view of these systems and their usage.

Experimental area of the CERN Antiproton Decelerator

Nuclear Physics A, 1999

The CERN Antiproton Decelerator will deliver low energy beams to four experimental beam-lines installed within the accelerator circumference. The limited space available imposes tight constraints on the topology of the beam-lines needed by the experimental devices. In this paper, the general layout of the experimental area is reviewed. Furthermore, a discussion of the so-called measurement line for AD beam property measurements is included.

Extra Low ENergy Antiproton (ELENA) ring and its Transfer Lines: Design Report

This Report gives a full description of the ELENA Ring to be built within the circumference of the Antiproton Decelarator (AD) Ring, in Building 193 at CERN. The ELENA ring will further decelerate the antiprotons coming from the AD at the momentum of 100 MeV/c down to 13.7 MeV/c, which corresponds to the kinetic energy of 100 keV before extracting to the physics experiments in the same building. The history of such an extra low energy antiproton ring at CERN goes a long way back, and even to the Decelerator’s previous incarnation, the Low Energy Antiproton Ring (LEAR), which came into operation in 1983. Already at that time, there were physics’ requests to further decelerate the antiprotons expected from LEAR by proposals for ELENA. Appendix I illustrates the cover pages of two such CERN documents from 1982.

An Antiproton Decelerator in the CERN PS Complex

1996

The present CERN PS low-energy antiproton complex involves 4 machines to collect, cool, decelerate and supply experiments with up to 1010 antiprotons per pulse and per hour of momenta ranging from 0.1 to 2 GeV/c. In view of a possible future physics ...