Automatic beam steering in the CERN PS Complex

Abstract

The recombination, transfer and injection of the four beams from the PS Booster to the PS Main Ring, have a high level of intricacy and are a subject of permanent concern for the operation of the PS Injector Complex. These tasks were thus selected as a test bench for the implementation of a prototype of an automatic beam steering system. The core of the system is based on a generic trajectory optimizer, robust enough to cope with imperfect observations. The algorithmic engine is connected to pickup monitors and corrector magnets and its decision can be validated by the operator through a graphics user interface. Automatic beam steering can only be ef®cient if the beam optics is fully con®rmed by experimental observations, a condition which forces the systematic elimination of errors both in hardware and software.

Optimal β-beam at the CERN-SPS

“…The design of a β-beam reaching this maximum γ is technically equivalent to the lower-γ option previously considered, for which a feasibility study already exists [27]. A major improvement in sensitivity to θ 13 and δ is achieved by increasing γ.…”

“…This paper considers instead the possibility of using the existing CERN-SPS up to its maximum power, allowing a beam with γ = 150 (250) for 6 He ( 18 Ne) ions (some preliminary results of this study were presented in [26]). The design of this β-beam is essentially as described in [27].…”

“…In all cases an intensity of 2.9 × 10 18 6 He and 1.1 × 10 18 18 Ne decays per year [27] and an integrated luminosity corresponding to 10 years are assumed. Although these luminosities have been estimated for simultaneous ion circulation (fixing the ratio of γ's to 1.67) reference [29] argues they are achievable even if the ions circulate separately at the same γ, by The paper is organized as follows.…”

Explicit thin-lens solution for an arbitrary four by four uncoupled beam transfer matrix

“…Equation (13) gives the dimensionless form of Eq. (7) and, additionally, one sees that while the original system (7) is formed by the product of 2n þ 1 interleaved thin-lens and drift matrices (with neighboring drifts lumped together), the system (13) includes only n þ 2 matrices depending on unknowns (there are n þ 2 unknowns: n lens strengths plus two variables characterizing the block length and the position of the lens inside the block) and n of them are P matrices.…”

“…Instead we will provide an explicit solution which utilizes 13 lenses if the parameters m and p are fixed and are independent from the input matrix M, and 12 lenses if m and p can be varied. The main idea of our solution is the reduction of the 2D problem (13) to two independent or, more exactly, almost independent 1D problems by constructing thin-lens blocks which can act in the horizontal and the vertical planes similar to a single P matrix, but whose actions for both planes can be chosen independently. At first we will consider a solution of the 1D problem in terms of P matrices.…”