Perturbation of relevant resonance for slow extraction efficiency increase

Alexeev, N.N.; Bereznitsky, S. L.; Bolshakov, A. E.

doi:10.1109/pac.1997.749612

Cited by 3 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The application of higher-order multipole fields to manipulate the spatial density of the beam presented to the extraction septum is not a new concept and has been reported various times in literature [5][6][7]. It is one of the main slow extraction beam loss reduction techniques pursued at CERN in recent years [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Demonstration of slow extraction loss reduction with the application of octupoles at the CERN Super Proton Synchrotron

Fraser

Goddard

Kain

et al. 2019

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

The powering of octupoles during third-integer resonant slow extraction has been studied and recently tested with the beam at the CERN Super Proton Synchrotron (SPS) in order to increase the extraction efficiency and reduce the induced radioactivity along the extraction straight. The octupoles distort the particle trajectories in phase space in such a way that the extracted separatrix is folded, which decreases the particle density impinging the wires of the extraction septum at the expense of increasing the extracted beam emittance. During experimental SPS machine studies a reduction of over 40% in the specific (per extracted proton) beam loss measured at the extraction septum was achieved. In this paper, the prerequisite studies needed to safely deploy the new extraction scheme in a limited time-frame are described, the experimental results are presented and an outlook given toward the next steps to bring slow extraction with octupoles into routine operation.

show abstract

Section: Introductionmentioning

confidence: 99%

Demonstration of slow extraction loss reduction with the application of octupoles at the CERN Super Proton Synchrotron

Fraser

Goddard

Kain

et al. 2019

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

show abstract

“…Here, we would like to focus on the concept of increasing the step size while keeping the beam size confined in the extraction acceptance channel by using higher-order multipoles. This discussion is not new and appears first in the literature, as far as we could determine, in a 1997 conference report [2]. Attention to this technique has grown again recently, as can be seen in Refs.…”

Section: Introductionmentioning

confidence: 77%

Third integer resonance extraction with presence of higher multipoles

Nagaslaev

Brown

Tomizawa

2019

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

The slow resonant extraction of a beam in a storage ring is a very well-established technique. Several high-energy physics accelerator facilities around the world are currently using this technique for highintensity beam operations. As the demand for beam power is constantly growing, extraction efficiency in many cases is becoming a limiting factor. In this report, we discuss a new effective approach to improving the slow extraction efficiency by using configurations of higher multipoles. We will describe this approach, determine optimal multipole configurations, and present the results of simulations to support the proposed recipe. We found that, with the use of higher multipole field content, the extraction efficiency can be improved, and, therefore, the level of prompt and residual radioactivity in the accelerator components and surrounding buildings can be reduced by as much as 40% or more. We also explored manipulating the higher-order effects produced in the pure sextupole configurations for the same purpose and demonstrated that similar results can be achieved by only rearranging the sextupole magnets in the lattice.

show abstract

“…Historically, Fermilab has chosen half-integer extraction for a variety of reasons; however, we will choose third integer because the existing working point of the Debuncher is close to a third integer resonance, and because there is much more experience with third integer resonant extraction worldwide. Also, interesting techniques are currently being developed to increase the efficiency of third integer extraction, which we might hope to exploit [29].…”

Section: Resonant Extractionmentioning

confidence: 99%