Innovation and Partnerships Office

Shock Injector Enabling Clinical Use of Electron Beam Therapy – Low-Laser Energy Electron Injection into Laser Plasma Accelerators 2015-150


  • Clinical use of electron beam therapy
  • Electron source for ultrafast electron diffraction (UED)
  • Compact Bremsstrahlung source


  • Produces stable electrons using low laser energy
  • Allows for highly controlled electron beam placement
  • Shortens cancer treatment time and increases efficacy
  • Enables positionable electron beam source


Berkeley Lab researchers led by Wim Leemans have invented a solution to expand the safe, effective use of electron beam therapy using laser plasma accelerator technology. A compact device, called the Shock Injector, creates a sharp density transition for the stable, highly controllable injection of 1-10 MeV electrons suitable for brachytherapy treatments. The electrons are achieved with 10 mJ of laser energy enabling the potential use of hollow core fiber optics for percutaneous procedures.

The Shock Injector consists of a small nozzle that delivers a concentrated jet of gas into a small space. A ramp is located below the nozzle and is set at a particular angle to control the density change across the shock. This forces the gases to produce two distinct regions of varying density, which provides controlled injection of electrons.

Electrons are a good source for radiotherapy because they deposit their energy locally. Current electron beam therapies for cancer are limited to interoperative procedures. The Shock Injector, combined with the fiber optic, enables electron acceleration to occur millimeters away from the tumor site, eliminating the need for large linear accelerators. The proximity of the source to the tumor, in conjunction with the depth dose curve of electrons, decreases radiation contact with surrounding tissues, reducing morbidity. This technology extends to any application where it benefits to have a compact, positionable 1-10 MeV electron beam source.

STATUS: Patent pending. Available for license or collaborative research.

DEVELOPMENT STAGE: Proven principle. 


Laser Accelerator-Driven Particle Brachytherapy, 2014-175