5 documents found, page 1 of 1
Filamentation of a relativistic proton bunch in plasma
Verra, L.; Amoedo, C.; Torrado, N.; Clairembaud, A.; Mezger, J.; Pannell, F.; Pucek, J.; van Gils, N.; Bergamaschi, M.; Della Porta, G. Z.; Lopes, N.We show in experiments that a long, underdense, relativistic proton bunch propagating in plasma undergoes the oblique instability, which we observe as filamentation. We determine a threshold value for the ratio between the bunch transverse size and plasma skin depth for the instability to occur. At the threshold, the outcome of the experiment alternates between filamentation and self-modulation instability (evi...
Development of the self-modulation instability of a relativistic proton bunch i...
Verra, L.; Wyler, S.; Nechaeva,T.; Pucek, J.; Bencini, V.; Bergamaschi, M.; Velotti, F.; Della Porta, G. Z.; Gschwendtner, E.; Muggli, P.; Agnello, R.Self-modulation is a beam–plasma instability that is useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing the ratio between the initial transverse size of the bunch and the plasma skin depth, the instability occurs later along the bunch, or not at all, over a fixed plasma length because the amplitude of the ...
The AWAKE Run 2 Programme and beyond
Gschwendtner, E.; Lotov, K.; Muggli, P.; Wing, M.; Agnello, R.; Ahdida, C. C.; Gonçalves, M. C. A.; Andrebe, Y.; Apsimon, O.; Apsimon, R.Plasma wakefield acceleration is a promising technology to reduce the size of particle accelerators. The use of high energy protons to drive wakefields in plasma has been demonstrated during Run 1 of the AWAKE programme at CERN. Protons of energy 400 GeV drove wakefields that accelerated electrons to 2 GeV in under 10 m of plasma. The AWAKE collaboration is now embarking on Run 2 with the main aims to demonstra...
Analysis of proton bunch parameters in the AWAKE experiment
Hafych, V.; Caldwell, A.; Agnello, R.; Ahdida, C. C.; Aladi, M.; Amoedo Goncalves, M. C.; Andrebe, Y.; Apsimon, O.; Apsimon, R.; Bachmann, A.-M.A precise characterization of the incoming proton bunch parameters is required to accurately simulate the self-modulation process in the Advanced Wakefield Experiment (AWAKE). This paper presents an analysis of the parameters of the incoming proton bunches used in the later stages of the AWAKE Run 1 data-taking period. The transverse structure of the bunch is observed at multiple positions along the beamline us...
Proton beam defocusing in AWAKE: comparison of simulations and measurements
Gorn, A.; Turner, M.; Adli, E; Agnello, R.; Aladi, M.; Andrebe, Y.; Apsimon, O.; Apsimon, R.; Bachmann, A. -M.; Baistrukov, M. A.; Batsch, F.In 2017, AWAKE demonstrated the seeded self-modulation (SSM) of a 400 GeV proton beam from the Super Proton Synchrotron at CERN. The angular distribution of the protons deflected due to SSM is a quantitative measure of the process, which agrees with simulations by the two-dimensional (axisymmetric) particle-in-cell code LCODE to about 5%. The agreement is achieved in beam population scans at two selected plasma...