Chairs
Professor Patric Muggli, Max-Planck-Institut für Physik, Germany
Professor Patric Muggli, Max-Planck-Institut für Physik, Germany
Professor Muggli has been the leader of the Future Accelerators Group/AWAKE at the Max Planck Institute for Physics (MPP), in Munich, Germany since April 2011. He has held a CERN Scientific Associateship since July 2016. As Physics and Experiment Coordinator, he is leading the experimental program on the AWAKE Proton-Driven Plasma Wakefield experiment at CERN. He is also a member of the Management and Technical Board of the AWAKE program. Professor Muggli is a Fellow of the American Physical Society, an IEEE Nuclear Plasma Science Society Distinguished Lecturer, and a Fellow of IEEE. He is also a member of the panel on advanced and novel accelerators within the International Committee for Future Accelerators (ICFA). He received the 2011 Particle Accelerator Science and Technology Award.
08:45-09:15
The AWAKE Experiment at CERN
Dr Edda Gschwendtner, CERN, Switzerland
Abstract
AWAKE, the Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN, pursues the demonstration of electron acceleration in plasma. The 400 GeV/c SPS proton beam, with a rms bunch length of 6 – 15 cm drives strong wakefields in a 10 m long rubidium plasma with an electron density of 10^14 – 10^15 cm3. In a first measurement campaign the AWAKE experiment has proven that the proton beam self modulates into micro-bunches, which resonantly drive the wakefields. In 2018 the experiment aims to show the acceleration of electrons in the plasma to GeV energies. An overview of the AWAKE experiment and its physics as well as the most recent result will be presented. The future experimental program, its challenges and of the technology to HEP, will be discussed.
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Dr Edda Gschwendtner, CERN, Switzerland
Dr Edda Gschwendtner, CERN, Switzerland
Edda Gschwendtner obtained her PhD in physics from the Vienna University of Technology, Austria working at CERN on benchmarking the particle background in the LHC experiments. Since 2005 she has been a senior member of the CERN scientific staff. During the last 20 years she was involved in several accelerator and particle physics projects, such as the SPS and LHC accelerators and the ATLAS experiment, she was responsible for the CERN Neutrino Gran Sasso beam-line and is a member of several international scientific advisory committees.
Since 2012 she has led the AWAKE Project at CERN and she is the AWAKE Technical Coordinator, in charge of the design, integration, commissioning and operation of the experiment. Edda’s area of research involves also Physics Beyond Colliders studies on HEP particle physics applications based on the AWAKE technology.
09:30-10:00
AWAKE electron injector and diagnostics
Dr Oznur Mete Apsimon, University of Manchester and the Cockcroft Institute, UK
Abstract
AWAKE is a unique experiment investigating plasma acceleration driven by 400 GeV protons from CERN’s Super Proton Synchrotron (SPS). Experiment is based on a 10m long plasma section located at the end of an SPS transfer line, which had previously served CERN Neutrinos to Gran Sasso (CNGS) experiment. The first goal of the experiment is observation of a phenomenon called the self–modulation instability which is a transverse instability leading to the modulation of 12cm long proton beam at about plasma frequency. This effect is important as the modulated bunch drives the plasma resonantly resulting into larger plasma wakefields. The second goal of this experiment is to demonstrate acceleration of a probe beam in plasma wakefields driven by modulated proton beam. A probe beam is generated externally by an electron source, which consists of an RF gun and a booster linac. 200pC electron beam reaches to 5MeV at the end of the gun and is boosted up to 16-20MeV by the linac. Electrons generated by this source will be transferred via a transfer line into the experimental area and injected into the plasma cell, synchronised with protons. Shape of the transfer line is a deciding factor on the normalised emittance budget of electrons limiting it to 2 mm mrad. Injector is equipped with pepper pot and quadrupole scan diagnostics, allowing emittance monitoring during beam set-up before the injection. In this talk, after a brief introduction, Dr Mete Apsimon will present the layout of the external electron source and performance of emittance diagnostics.
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Dr Oznur Mete Apsimon, University of Manchester and the Cockcroft Institute, UK
Dr Oznur Mete Apsimon, University of Manchester and the Cockcroft Institute, UK
In 2005, Dr Mete Apsimon worked at CERN as a graduate student to work on tests and conditioning of the high frequency, high gradient normal conducting accelerating structures as an underpinning technology for the CLIC Project. She obtained her PhD from École polytechnique fédérale de Lausanne in 2011, she was working at CERN on experimental characterisation and optimisation of the PHIN photoinjector as the CLIC drive beam injector. Soon after, she was awarded a postdoctoral research fellowship at CERN to devise a local orbit bump assisted, graphite based beam halo cleaning system for SPS in order to ultimately improve the integrated luminosity of the LHC. In 2013, she joint the accelerator physics group in the University of Manchester (UoM) as a member of the Cockcroft Institute of Accelerator Science and Technology (CI) to work on plasma based advanced accelerator concepts. In 2016, she has been short-listed and interviewed by the Rutherford Fellowship committee. Currently, she works on the AWAKE Project while developing a capillary-based discharge plasma source after securing the STFC Early Stage Impact Acceleration funding.
10:15-10:45
FLASHForward – plasma wakefield accelerator science for high average power applications
Dr Richard D'Arcy, DESY, Germany
Abstract
The field of particle acceleration in plasma waves has seen remarkable progress in the last two decades. These days, acceleration gradients of more than 10 GV/m can be readily achieved using either ultra-short intense laser pulses or high-current density particle beams as plasma wakefield drivers. With the demonstration of first GeV electron beams and a trend towards improved reproducibility, beam quality and control over the involved plasma processes, plasma-acceleration techniques are drawing considerable interest in the traditional accelerator community. As a consequence, DESY, Germany's leading accelerator centre, has established a research programme for beam-driven plasma-based novel acceleration techniques with the goal to symbiotically combine conventional and new accelerator concepts for applications. This presentation will give an introduction into these emerging activities, show first theoretical and experimental results and outline the DESY PWFA flagship project, FLASHForward.
FLASHForward is a pioneering beam-driven plasma-wakefield experiment that aims to produce, in a few centimetres of ionized hydrogen, electron beams of energies exceeding 1.5 GeV that are of sufficient quality to demonstrate gain in a free-electron laser. The experimental beamline will allow for milestone studies assessing plasma-internal particle injection regimes, external injection, and controlled beam capturing and release for subsequent applications. The facility provides a unique combination of low-emittance GeV-class electrons from the superconducting MHz repetition rate, high-average power accelerator FLASH synchronized to a 25 TW laser interacting in a windowless, optically accessible, versatile plasma target. Experiments will commence in 2018 and are foreseen to run for the next decade, opening up new avenues in this highly dynamic research field.
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Dr Richard D'Arcy, DESY, Germany
Dr Richard D'Arcy, DESY, Germany
Richard D’Arcy has held the position of Scientific Coordinator of the beam-driven plasma wakefield accelerator (PWFA) project FLASHForward at DESY, Germany since early 2017. From 2015 he led investigations into the implementation of an X-band TDS device at FLASHForward for fs-level PWFA bunch characterisation as a DESY Fellow. Prior to joining the field of plasma acceleration Richard completed postdoctoral stays at Fermilab, US and Rutherford Appleton Laboratory, UK working on high intensity proton sources for the next generation of high-energy target and collider experiments. In 2012 he received his PhD from University College London, UK in the field of novel acceleration techniques through contributions to the Fixed-Field Alternating Gradient proof-of-principle accelerator experiments EMMA at Daresbury Laboratory, UK and COMET at KEK, Japan.
11:15-11:45
Positron acceleration in plasma: challenges and progress
Dr Spencer J Gessner, CERN, Switzerland
Abstract
Plasma Wakefield Acceleration (PWFA) is an exciting technology for accelerating particle beams to high energies in short distances. The ultimate application of this technology is an energy-frontier linear collider. A plasma-based linear collider has the potential to be more compact and efficient than RF-based colliders, while being less expensive. Of all the challenges on the path to a plasma-based linear collider, the acceleration of positrons in plasma is by far the most daunting. Plasmas are unique in that they are asymmetric accelerators, with light, mobile plasma electrons responding to the driving beam or laser fields, and the heavy ions remaining at rest. Many features of the plasma wakefield that are attractive for accelerating electrons are absent for positrons. In this talk, Dr Gessner will explain the physics of positron acceleration in plasma and reprise the state of research on the topic. The focus will be on the three main techniques tested so far: the quasilinear regime, nonlinear regime, and hollow channel regime. The next steps in this research will be described by S Corde in a following talk.
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Dr Spencer J Gessner, CERN, Switzerland
Dr Spencer J Gessner, CERN, Switzerland
Spencer Gessner received his undergraduate degree in physics from the University of California Santa Barbara in 2009. In 2010 he was admitted to Stanford University, where he received his PhD in physics in 2016. At SLAC, he started his research with the ATLAS group, but in 2011 switched to research at FACET with a focus on theoretical and experimental aspects of positron acceleration in a plasma wake-field accelerator (PWFA). In the course of his work, Spencer covered a very broad range of topics: from developing the energy spread diagnostic at FACET, to theoretical and experimental aspects of creating hollow plasma channels for acceleration of positrons. Spencer developed a highly innovative approach to this challenging problem and found a number of original solutions. The experimental demonstration of positron acceleration in hollow-channel PWFA was an impressive validation of his approach. His research was supervised by Professor Tor Raubenheimer. After receiving his PhD in 2016, Dr Gessner became a fellow at CERN, where he is studying proton beam-driven plasma wakefield acceleration as a member of the AWAKE Collaboration.
12:00-12:30
Positron acceleration in plasma: solutions, future experiments, and the path to a linear collider
Professor Sébastien Corde, Ecole Polytechnique, France
Abstract
The concept of plasma-based particle accelerators is a promising path to overcome the limitations of conventional accelerator techniques. They hold out the promise of more compact, more affordable and higher-energy particle accelerators, and are increasingly considered as a mean to push the energy frontier of particle physics even higher. But for application to high-energy physics and to a linear collider, it is however imperative for plasma-based particle accelerators to also be capable of accelerating positrons, while most of the research effort so far has been on the acceleration of electrons. This is crucially important as positron acceleration in plasma is a much more challenging task than electron acceleration.
In this talk, Professor Corde will give a comprehensive overview of the different challenges of positron acceleration in plasma, highlighting the different routes under study, their problems and potential solutions, and the way forward to address them. Indeed, different variants of plasma-based acceleration are considered for positron acceleration in plasmas, the quasi-linear regime, the nonlinear regime and the hollow plasma channel, and they all have different advantages and flaws. Future experiments on positron acceleration and the path to a linear collider will also be discussed.
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Professor Sébastien Corde, Ecole Polytechnique, France
Professor Sébastien Corde, Ecole Polytechnique, France
Sébastien Corde started his career in the Laboratoire d'Optique Appliquée at Ecole Polytechnique to work on the development of laser-plasma accelerators and their applications to femtosecond light sources. Within a few years he became an expert in his field, publishing an in-depth review article in Reviews of Modern Physics covering the research area of femtosecond x-ray sources from laser-plasma accelerators. Through a series of groundbreaking experiments, he pushed forward the understanding of the interaction underlying laser-plasma accelerators and demonstrated an innovative all-optical Compton gamma-ray source. Sébastien received four awards for his PhD, including the Outstanding Doctoral Thesis Research in Beam Physics Award from the American Physical Society. He continued his career in the plasma wakefield acceleration group at SLAC. The experiments that he conducted at FACET have led to fast experimental progress in the field of plasma wakefield acceleration, with many important milestones, in particular the demonstration of ultrahigh-field, low-energy spread acceleration of positrons in a plasma. Since then, Sébastien has been appointed as an Assistant Professor at Ecole Polytechnique, a top French engineering school. His research is at the interface between beam-driven and laser-driven plasma accelerators, focusing in particular on the topics of hybrid wakefield acceleration and plasma-based positron acceleration.