[Triumf-seminars] TRIUMF Accelerator Seminar today at 14:30

[TRIUMF Seminars]

Date/Time: Wed 2016-09-07 at 14:30

Location:  ISAC II Conf. Room  

Speaker:   Nicolas Savard (University of Victoria (UVic))

Title:     Preserving Electron Acceleration and Focusing in the Advanced Wakefield Experiment, AWAKE

Abstract: The Advanced Wakefield Experiment, or AWAKE, is an experiment based at CERN (European Organization for Nuclear Research) whose purpose is to demonstrate the acceleration of electrons using plasma wakefields driven by a charged particle bunch. As a proof-of-principle experiment, AWAKE will be propagating a high-energy proton bunch through 10 meters of plasma to drive the wakefields for electron acceleration. To accelerate the electrons, we want to inject them into regions of both focusing and acceleration within these wakefields behind the proton bunch. In order forthe electrons to stay within this optimal accelerating/focusing region, we need to maintain uniform plasma density within 0.2\%, and we need to inject when the wakefield phase-velocity is constant. To preserve uniform plasma density, we use a liquid heat-exchanging pipe which can maintainstable temperatures, and therefore uniform rubidium vapor/plasma densities, to within 0.2\%. We show that this is possible using Galden HT270 as a heat-exchanging liquid. We also show that additional components required for this system will need external heating to prevent heat-loss, and therefore temperature non-uniformity. Furthermore, using the PIC simulation OSIRIS, we study how changing size parameters of the initial proton bunch by $\pm$5\% affects the phase-velocity of the wakefield. It is seen that these parameter variations will not significantly affect the optimal region size and energy gain of injected electrons; so long as the electrons are injected at regions of $\xi$ near $\sigma_{zb}$ of the proton bunch and after 4 m of bunch propagation length in the plasma.


Stimulants available 15 minutes before the talk.

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