Abstract
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 deceleration and electron cooling. The AD started operation in July 2000 and has since delivered cooled beam at 100 MeV/c (kinetic energy of 5.3 MeV) to 3 experiments (ASACUSA, ATHENA and ATRAP) for 1500 h. The flux (up to 2.5 /spl times/ 10 pbar /s delivered in short pulses of 330 ns every 110 s) and the quality of the ejected beam are not far from the design specifications. A linear RF quadrupole decelerator (RFQD) was commissioned in November 2000 to post-decelerate the beam for ASACUSA from 5.3 MeV to about 15 keV. Problems encountered in converting the fixed 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 special diagnostics to cope with beams of less than 10/sup 7/ pbars, will be reviewed. Possible future developments will be sketched.
Highlights
The new low-energy antiproton facility at CERN was successfully commissioned, starting in fall 1998 (Fig. 1) [1]
A first four-month particle physics run took place from July to October 2000 followed by a second run, which started after the shutdown of the CERN machines at the end of April 2001
The Antiproton Decelerator (AD) is a simplified scheme to provide low-energy antiprotons. It consists of just one ring, the former 3.5 GeV/c Antiproton Collector (AC), which has been modified to include deceleration down to 0.1 GeV/c [3]
Summary
The new low-energy antiproton facility at CERN was successfully commissioned, starting in fall 1998 (Fig. 1) [1]. The first two experiments which are supposed to produce antihydrogen, use degrader foils for the last deceleration from 5.3 MeV to near rest, while ASACUSA (Atomic Spectroscopy and Collisions Using Slow Antiprotons) uses a decelerating RFQ (RFQD). This RFQD [2] was installed in the experimental area in October 2000 and has been successfully commissioned. There are still periods with reduced performance or complete breakdown, due to difficulties with various hardware and software components In this status report, some conclusions are draw from the commissioning and first year of operation, with prospects for future improvements
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
