16 May 2018
Discover our research
Particle acceleration at ELI-ALPS
Ashutosh Sharma has explored the possibility of using the high power laser at ELI-ALPS to accelerate particles. In a recent article in Nature Scientific Reports he concludes that it should be feasible to achieve high energy proton beams with peak energies more than 300 MeV from thin near-solid gas targets using the highly efficient magnetic vortex acceleration mechanism.
‘The motivation for this work is the need for high quality proton beams for cancer treatment,’ Sharma explains. The petaWatt facility at ELI-ALPS is suitable for making such beams. ‘The relatively high repetition rate of 10 Hz for such a powerful laser system means that there is a need for a compatible and highly efficient target to act as a proton source. High density gas targets may be the most obvious choice with typical diameters from few millimeters down to hundreds of microns.’
Circular polarized light for confinement
Numerical investigations were used to explore the possibilities of generating a high quality proton beam from firing a circularly polarized 20 fs - 2 PW laser into a thin, dense jet of hydrogen gas. The results in this work highlighted that high-energy proton beam can be experimentally realized by using near-critical density hydrogen gas target with an optimum plasma thickness and by controlling the laser beam parameters. ‘An advantage of using circular polarized light is that it leads to the generation of helical shaped electron beams, which act as collimators for the proton beam, effectively narrowing the energy spectrum of the protons,’ the researcher says.
Numerous potential applications
This novel method of ion acceleration driven by short laser pulse has numerous potential applications, such as proton cancer treatment, Sharma says. ‘There might also be other possible applications in medical and nuclear physics. At ELI-ALPS, we have the possibility to combine proton beams with a THz facility. That will not only enable us to post-accelerate the proton beam, but also to use the Thz source to image the cancer cells and subsequently treat them with the proton beam. This is currently being exploring in conjunction with the ‘Biomedical Group’ at ELI-ALPS.’
Read the article here: https://www.nature.com/articles/s41598-018-20506-x
Nuclear fusion inside cancer cells
In a recent paper in Nature Scientific Reports, ELI Beamlines researchers together with colleagues from LNS-INFN (Catania), DoP-UoN (Naples) and FBK (Trento), demonstrated for the first time how to use proton-boron nuclear fusion to achieve more effective treatments of cancer cells. Third author and ELI Beamlines Senior Researcher Daniele Margarone explains how.
‘In short: we have realized nuclear fusion inside a cancer cell. We injected molecules containing 11Boron into in-vitro prostate cancer cells and bombarded them with a proton beam. The nuclear fusion reaction between the protons and the boron results in the generation of alpha particles, with a predominant energy around 4 MeV. This principle is not only interesting for cancer treatment, but also for generating fusion energy, without producing unwanted neutrons.
The advantage of using protons over other particles in cancer radiation therapy, is that they deposit their energy mostly at the end of their range, confining the high dose area to the tumor volume and leaving the surrounding healthy tissue unhampered. With our method, we can enhance the effectiveness of proton therapy without inducing unwanted side effects: the alpha particles are generated within the tumor cells and lose their energy in about 30 microns, which is the approximate size of a typical human cell.
In the paper we report about 3 different experiments, under different conditions, leading to the same proof of principle. We have already patented this method, and are now working on acquiring more statistics. I am very happy to report that the proton therapy center here in Prague is already very interested, and wants to work with us to bring this method into a clinical trial phase. They have allocated part of their beam time for this research. Together, we will work on potential treatment and planning and on in-vivo experiments, to eventually make the step towards trying this out on actual patients.
For our method, it doesn’t matter how the protons are accelerated. However, laser-driven acceleration potentially has major advantages, since it would be possible to use more compact and less expensive accelerators, thereby making proton therapy accessible for more hospitals, which is the long-term goal of the ELIMED international network launched by ELI Beamlines researchers. This field is an excellent example of the application-driven research that can be carried out by users of the ELI Beamlines facility.’https://www.nature.com/articles/s41598-018-19258-5
Get involved in Nuclear Photonics
From 24 to 29 June, Brasov, Romania will host the second edition of the International Conference on Nuclear Photonics. Conference co-chair Chang Hee Nam, director of the Center for Relativistic Laser Science (CoReLS), Institute for Basic Science in Korea, explains why you should attend.
‘Nuclear Photonics is an emerging research field, that merges high intensity laser physics, plasma physics, accelerator physics, and nuclear physics. Since up until now these have been fairly separated research areas, the Nuclear Photonics conference is the ideal event to meet people from the other side, and get inspired with new ideas for future research.
Take me for example. At CoReLS, we currently host the most powerful operating laser in the world. With this 4 petaWatt laser, we are developing new kinds of particle and light sources, such as GeV electron beam, X-ray and gamma ray sources. At the conference, I hope to gain insights into how the nuclear physics people can use these kinds of sources for their investigations, and under what conditions they want to make use of our new energetic particle and light sources.
The conference covers a wide variety of topics, ranging from laser developments, laser-plasma interactions, and fundamental nuclear physics, to nuclear astrophysics. To be able to fully understand each other, we will start with four different tutorials, introducing the different fields to those who are interested but no insiders yet.
All in all, this conference will be the starting point of exciting new physics and new collaborations. I think this is a unique opportunity to widen your scientific scope.
For more information, visit the conference website: http://nuclearphotonics2018.eli-np.ro/