Disputation: Jian Bin Ben Chen

Doctoral candidate Jian Bin Ben Chen at the Department of Physics, Faculty of Mathematics and Natural Sciences, is defending the thesis 

"Instability and Beam-Beam Study for Multi-TeV PWFA e+e- and γγ Linear Colliders"

for the degree of Philosophiae Doctor.

portrait of the candidate

The PhD defence and trial lecture are fully digital and streamed using Zoom.  The chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants' and then choose 'Raise hand'. 


Trial lecture

“Breakdown Processes in Gases/Plasmas: Operating examples in laboratories and space”



Recording of the trial lecture will be available here on January 21 until January 25.



Main research findings

Beam-driven plasma wakefield acceleration (PWFA) is considered one of the most promising novel acceleration technologies capable of drastically shrinking the footprints of high-energy particle colliders. However, there are several challenges that need to be addressed before PWFA can be deployed for high-energy, high-efficiency, high beam brightness particle colliders. Transverse instabilities due to interactions between particle beams and accelerating structures are known to restrict the maximum beam charge in conventional linear colliders such as CLIC (Compact Linear Collider), and are considered one of the most important challenges for PWFA accelerators.

Using a simplified model (benchmarked against particle-in-cell simulations) to describe the PWFA transverse instability in the form of a wake function drastically simplifies computationally expensive particle-in-cell simulations, and allows for a parameter scan for a 1.5 TeV PWFA electron accelerator. The results reveal a parameter set with reasonable stability, energy spread and efficiency, which is used to perform beam-beam studies of multi-TeV PWFA electron-positron and photon linear colliders. The beam-beam studies demonstrate that such colliders may offer significant luminosity improvements over CLIC, which also allows these colliders to reach luminosity goals at lower beam power. However, the examined parameters for both collider types also produce more unwanted background particles.


Contact information to Department: Line Trosterud Resvold

Published Jan. 11, 2021 2:53 PM - Last modified Jan. 21, 2021 10:34 AM