Finn Pedersen

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A simplified scheme for the provision of antiprotons at 100 MeV/c based on fast extraction is described. The scheme uses the existing p production target area and the modified Antiproton Collector Ring in their current location. The physics programme is largely based on capturing and storing antiprotons in Penning traps for the production and spectroscopy(More)
At intensities > 1.5 × 1012 protons per ring, and at reduced RF voltage, fast growing beam loading instabilities occur in the Booster (PSB) with loss of beam bunching. The observed thresholds are reported; they are different from those given by Robinson's1 criterion and occur with a different frequency. To explain this and other observations, a model of the(More)
The beam-cavity instability threshold as given by the Robinson1 criterion for the open loop case is often improved by phase, amplitude and tuning loops. The improvement obtained is, however, limited by cross coupling as the transfer functions vary with the relative beam loading. A more powerful scheme is fast additive feedback around the final amplifier(More)
Longitudinal instabilities have long been trouble-some in the Booster1). They are described by the coupledbunch mode number n = 0 to 4 for five bunches, and by the within-bunch mode number m = 1 for dipole, m = 2 for quadrupole, m = 3 for sextupole, and so on (Fig. 1). The normal beam control system damps the rigid-bunch oscillation (m = 1) when all five(More)
The first phase of the heavy ion physics program at the LHC aims to provide lead-lead collisions at energies of 5.5 TeV per colliding nucleon pair and ion-ion luminosity of 10<sup>27</sup>cm<sup>-2</sup>s<sup>-1</sup>. The transformation of CERN&#8217;s ion injector complex (Linac3-LEIR-PS-SPS) presents a number of beam physics and engineering challenges,(More)
Ab stract 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(More)
This distribution fits well with distributions observed in proton synchrotrons and makes several analytical calculations for bunched beams in longitudinal phase space possible. For any shape of the focusing force the line density becomes proportional to the potential well. Self-forces caused by space-charge and inductive wall impedances are thus(More)
The Antiproton Accumulator uses a conventional RF system for bunched beam manipulations within the ring. These require precise control of the bucket size, the synchronous phase angle, and the radial position across the width of the vacuum chamber, over which the magnetic properties of the ring vary significantly. Several different manipulations are(More)