Patent Number: 
Section: claims

1. A method for generating a focused beam of charged particles, the method comprising:a) generating a beam of charged particles;b) emitting a laser pulse;c) generating a focusing magnetic field structure in a target by means of an interaction of said laser pulse with said target; andd) causing at least partial penetration of the beam of charged particles into said focusing magnetic field structure,wherein in step b), a laser contrast of the laser pulse is increased. 2. The method according to claim 1, wherein a power of the laser pulse is substantially between 1 terawatt and about 100 terawatts. 3. The method according to claim 1, wherein a duration of the laser pulse is substantially between about 10 femtoseconds and about 10 picoseconds. 4. The method according to claim 1, whereinin step c) the laser pulse is focused on the target at the level of a focal spot, andin step d) the beam of charged particles passes at least partially through said focal spot. 5. The method according to claim 1, wherein the target is made at least in part of a metal. 6. The method according to claim 5, wherein the target is made at least in part of a metal selected from a group comprising gold, copper and aluminum. 7. The method according to claim 6, wherein the thickness of the target lies substantially between 500 nanometers and about 100 micrometers. 8. The method according to claim 1, whereinthe target extends substantially along a plane of extension between a front face and a rear face, said faces being opposite to one another in a thickness direction perpendicular to the plane of extension and separated by a thickness measured in said thickness direction, andin step d) said beam passes through the target substantially in said thickness direction. 9. The method according to claim 1, wherein step a) of generating a particle beam comprises:emitting a generating laser purse; andgenerating a non-focused beam of particles by means of an interaction of said generating laser pulse with a generating target. 10. A device for generating a focused beam of charged particles, the device comprising:means for generating a beam of charged particles;a laser source for emitting a laser pulse;a target for generating a focusing magnetic field structure by means of an interaction of said laser pulse with said target, said beam of charged particles penetrating at least partially into said magnetic field structure; anda device for increasing a laser contrast of the laser pulse. 11. The device according to claim 10, wherein the means for generating a beam of charged particles comprising:a laser source for emitting a generating laser pulse; anda generating target for generating a beam of charged particles upon an interaction of said generating laser pulse with said generating target.