Negative ions from a laser accelerator:
Negative ions, fragile atomic systems, are important in accelerator-based
physics.Their generation from a laser driven plasma seems highly
unlikely because of the huge electromagnetic fields inside the plasma.
Nevertheless, we detected a high number of negative oxygen ions
O^1- with MeV energies and, more recently C^1- and H^1- ions after
irradiation of a spray target, a MBI-patent, by intense (5×10^19
W/cm^2 ) and ultrashort (35 fs) laser pulses. Negative ions are
created when fast positive ions, laser accelerated inside a cylindrical
interaction zone, capture electrons from neutral target atoms in
the surrounding spray cloud.Thereby, the quality (emittance) of
the laser accelerated ions remains nearly preserved.The mechanism
implies also the existence of a large number of neutral atoms with
MeV energies (S.Ter-Avetisyan et al., Appl.Phys.Lett.99(2011)051501)
which could be proven in a recent LASERLAB-EUROPE access experiment.
Foto inside the new lab with shielding enclosure: experimental
chamber with 3 spectrometers for fast ion detection.
(LASERLAB EUROPA access experiment with Queens University
Belfast Nov2011 - Jan 2012 (Group of Prof. Borghesi and Dr.
For further and more general information please look to research
projects 2-01 (laser plasma research) and 1-02 (laser development).