Proton density after laser impact on a spherical solid density target: irradiated by an ultra-short, high
intensity laser (not in picture) the intense electro-magnetic field rips electrons apart from their ions and
creates a plasma. By varying the target geometry and laser properties, scientists could find optimal
regimes to accelerate high quality, directed ion beams that are currently studied in accompanying
experiments. Image Credits: Axel Huebl, HZDR, David Pugmire, ORNL).
(January 26, 2016) German team makes large computational gains in laser-driven radiation therapy of cancer
Since lasers were first produced in the early 1960s, researchers have worked to apply laser technology from welding metal to surgeries, with laser technology advancing quickly through the last 50 years.
Surgery, chemotherapy, and radiation therapy all play important roles in cancer treatment, and sometimes the best successes come from combining all three approaches.
Doctors usually do the most common form of radiation therapy with x-rays, which can penetrate tissue, killing the cancerous cells in deep-seated tumors. Unfortunately, these same x-rays can also damage healthy tissue surrounding the tumor.
Thus, in recent years, the use of beams of heavy particles, such as protons or ions, has come into focus. These beams can deposit most of their energy inside the tumor, while at the same time leaving the healthy tissue unharmed. Unfortunately, these beams come from bulky particle accelerators, which make the treatment cost prohibitive for many patients.
At the German research laboratory Helmholtz-Zentrum Dresden-Rossendorf (HZDR), researchers are looking into replacing particle accelerators with high-powered lasers. The electromagnetic fields of the laser can accelerate ions in a very short time, thus effectively reducing the distance needed to accelerate the ions to therapeutic energies from several meters to a few micrometers.
As a scientist experienced in accelerator research and laser physics, HZDR researcher Michael Bussmann aims for understanding and controlling this new method of particle acceleration to make it available for patient treatment. “I’m coming from accelerator research and laser physics, and what my team and I have been looking at is how we make best use of the high-power lasers so they can replace accelerators for applications like treating cancerous tumors,” Bussmann said.
“This is fundamental physics on the one hand, as the laser pulse rips apart all the matter found in a target, usually a very thin metal foil or a tiny sphere, separating the building blocks of atoms—negatively charged electrons and positively charged atomic nuclei, ions—from each other. This state of matter is called a plasma,” Bussmann explained. “On the other hand, it has real applications as well. Simulations play a role that is unique, as experiments are still not very reproducible and we can’t really diagnose what’s happening in a few femtoseconds.”