ion/electron/X-ray beams

Particle theraphy of tumours constitutes one of the most effective and most widely applicable therapy of cancer today. On the diagnostic side, phase-constrast imaging with collimated hard X-rays allows reliable dignosis of tumours at their earliest stage of development. Both advanced techniques rely currently on large-scale accelerators such as the Heidelberg Ion Therapy (HIT) Centre and the European Synchrotron Research Facility (ESRF) at Grenoble. The tremendous size and cost of these installations restrict their number to several therapy centres all over the world. Phase-contrast imaging has not even reached the stage of clinical use.

Recent advances in the physics of the interaction of femtosecond laser pulses with plasmas have revealed great potential for accelerating ions to multi-MeV energies. The concept is based on a thin foil exposed to an intense high-contrast ultra-short laser pulse. Electrons are pushed out of the target within a fraction of the laser pulse duration, resulting in electric fields of several TV/m at the boundaries of the foil. Protons and ions can acquire MeV energies per micrometre propagation length in these fields. The method affords promise for particle energies relevant for medical applications when PW-class lasers drive the interaction.

We focus our studies on mass-limited targets such as micro-spheres and diamond-like carbon (DLC) foils of only several nanometers thickness. They are predicted to relax demands on the laser pulse energy and hold promise for the production of dense electron pulses. These, in turn, can possibly be exploited for the generation of brilliant X-rays via Thomson backscattering.

Until the availability of PFS, these investigations will draw on ATLAS-100 as a laser driver and benefit from world-leading target design research at MAP’s target laboratory. The bright proton/ion and X-ray beams will be used for proof-of-concept cell-biologic studies and diagnostics of small specimen, respectively. To this end, we develop a beamline (HF-1/2) dedicated to the development of these novel particle and X-ray sources and their medical applications.

contact: D. Habs, J. Schreiber

references:

Enhanced Laser-Driven Ion Acceleration in the Relativistic Transparency Regime, A. Henig et al. Phys. Rev. Lett. 103, 045002 (2009)

Radiation-Pressure Acceleration of Ion Beams Driven by Circularly Polarized Laser Pulses, A. Henig et al. Phys. Rev. Lett. 103, 245003 (2009)

Laser-Driven Shock Acceleration of Ion Beams from Spherical Mass-Limited Targets, A. Henig et al. Phys. Rev. Lett. 102, 095002 (2009)