Conveners
Spill Ripples & Beam Quality: I
- Peter Forck (GSI Helmholtzzentrum für Schwerionenforschung GmbH(GSI))
The intensity ripples in the extracted beam are a crucial topic for clinical treatment, as a constant particle flux is required for optimal operation of the accelerator within safety regulations. Therefore, ripple mitigation techniques are widely used in facilities worldwide.
This talk discusses the intensity ripples at MedAustron by analysing the ripple frequency spectrum and the impact of...
Results of two topics are presented in this contribution.
The first one is the influence of some quantities on the spill quality of the KO extraction from the future GSI heavy ion synchrotron SIS100 studied with particle tracking simulations. This technique is still foreseen as standard slow extraction technique in SIS100. The results suggest that for such conditions the presently applied...
In this contribution, we will discuss the beam dynamics relevant for the KO extracted spill feedback loop by means of Xsuite simulations and measurements at GSI SIS-18. The fundamental limitations of this feedback scheme under typical machine settings and excitation waveforms will be highlighted.
This project has received funding from the European Union’s Horizon 2020 Research and Innovation...
The beam response to an external periodic excitation delivers relevant information about the ion-beam optics, tune distribution and stability of a circulating beam in a storage ring. In this contribution the horizontal beam response under conditions typical for slow extraction is presented for a coasting beam. The resulting spectrum exhibits a splitting behaviour. The single particle dynamics...
The Heidelberg Ion-Beam Therapy Centre HIT uses the RF-KO slow extraction method to extract the particles from the synchrotron. To improve the spill quality of the extracted beam a new RF-signal was investigated which increases the R-value from 92.5% to 97.5%. The signal is a multiband RF signal broadened with a random BPSK at 3 frequency bands. The new KO-DDS which generates the signal is in...
In this talk, we investigate the transit time of particles in a third-integer resonant extraction process. Transit time is defined as the number of turns a particle takes to get extracted once it is in the unstable region, i.e., outside the triangular separatrix. The study of transit time is important because transit time determines the beam response time during resonant extraction and thus...
The beam response to an external periodic excitation delivers relevant information about the ion-beam optics, tune distribution and stability of a circulating beam in a storage ring. In this contribution the horizontal beam response under conditions typical for slow extraction is presented for a coasting beam. The resulting spectrum exhibits a splitting behaviour. The single particle dynamics...
Radio-frequency (RF) techniques can be utilised to provide a tailored time structure to slow extraction users. In this contribution, a manipulation known as RF phase displacement is presented as a way of satisfying two different beam requests: (i) ~millisecond-scale spills for FLASH therapy/Radiation-to-Electronics users, and (ii) ~second-scale spills with nanosecond bunching for a dark-matter...
Spill uniformity is a key performance metric for the experimental users in the CERN North Area, who receive slow-extracted protons from the Super Proton Synchrotron. In this contribution, RF empty-bucket techniques are studied to suppress the low-frequency variations in the spill caused by power-converter ripple. The study includes simulation, measurement and the long-term experience after...
Inevitably, to evaluate the quality of the slow extracted beams delivered to experiments, we need to understand how different frequency components develop. How we evaluate this is to look at the beam spills in a beamline. However, while those are the end result and what the experiments see, they don’t directly represent how the different frequencies get imprinted into the spill. This is what...
Results of two topics are presented in this contribution.
The first one is the influence of some quantities on the spill quality
of the KO extraction from the future GSI heavy ion synchrotron SIS100
studied with particle tracking simulations.
This technique is still foreseen as standard slow extraction technique in
SIS100. The results suggest that for such conditions the presently...
