Roman Walczak

Senior Research Fellow

I arrived in the UK in 1993 to take my fellowship in Somerville and lectureship in the Physics Department. The UK is my fourth country after my native Poland, Switzerland and Germany where I lived and worked for many years; quite a long journey from state schools in Poland to Oxford. In 2019 I retired my Tutorial Fellowship to become a Senior Research Fellow.

Most of my research so far has been in experimental particle physics but in recent years I have been moving my main interests from particle to accelerator physics. In plasma (ionised gas, for example hydrogen), using a laser, one can move electrons away from ions creating a huge electric field; many orders of magnitude bigger then what one can get using current technology. Such a field can be used to accelerate particles and to build accelerators beyond the Large Hadron Collider era and beyond current X ray sources (synchrotron radiation), like Diamond near Oxford. Acceleration using plasma would move particle physics to a new territory and simultaneously would make tuneable wavelength, short pulse X ray sources affordable for Universities and hospitals.

My main expertise in particle physics is in the design of wire chambers and calorimeters and on physics beyond the Standard Model as well as on some aspects of Quantum Chromo Dynamics. I worked at the following accelerators: CERN: PS, ISR, SPS; and DESY: PETRA, HERA. At John Adams Institute for Accelerator Science at Oxford University, I am leading the Lasers for Accelerators (L4A) group.

Besides physics, I am working on a small family farm and I am a keen swimmer; I am holding one national swimming record in my age group.

My advice to my students: Only beginners compete. When you go to a higher level, your aim is quality.

Publications

'Guiding of high-intensity laser pulses in 100mm-long hydrodynamic optical-field-ionized plasma channels'
A Picksley, A Alejo, J Cowley, N Bourgeois, L Corner, L Feder, J Holloway, H Jones, J Jonnerby, Hm Milchberg, Lr Reid, Aj Ross, R Walczak, Sm Hooker
Physical Review Accelerators and Beams American Physical Society 23:8 (2020) 081303

Numerical modelling of chromatic effects on axicon-focused beams used to generate HOFI plasma channels
Aimee Ross, Aaron Alejo, Alexander von Boetticher, James Cowley, James Holloway, Jakob Jonnerby, Alexander Picksley, Roman Walczak, Simon Hooker
Journal of Physics: Conference Series IOP Publishing 1596 (2020)

Eupraxia, a step toward a plasma-wakefield based accelerator with high beam quality
D Alesini, A Aschikhin, A Beck, M Chen, E Chiadroni, M Croia, B Cros, A Del Dotto, M Ferrario, RA Fonseca, LA Gizzi, SM Hooker, L Labate, A Martinez De La Ossa, A Mosnier, A Mostacci, D Oumbarek Espinos, A Stella, EN Svystun, D Terzani, P Tomassini, JM Vieira, CP Welsch, SM Wiggins, J Wolfenden
Journal of Physics: Conference Series IOP Science 1350:1 (2019)

Status of the Horizon 2020 EuPRAXIA conceptual design study
G Fiore, RA Fonseca, M Galimberti, A Gallo, A Ghaith, D Giove, A Giribono, LA Gizzi, FJ Grüner, AF Habib, C Haefner, T Heinemann, B Hidding, BJ Holzer, SM Hooker, T Hosokai, M Huebner, A Irman, FJ Jafarinia, DA Jaroszynski, C Joshi, M Kaluza, M Kando, OS Karger, E Khazanov
Journal of Physics: Conference Series 1350:1 (2019)

Laser-driven high-quality positron sources as possible injectors for plasma-based accelerators
A Alejo, Roman Walczak, G Sarri
Scientific Reports Nature Research 9:1 (2019) 5279

Where Next?