https://doi.org/10.1140/epjb/e2004-00391-6
A sub-atomic microscope, superfocusing in channeling and close encounter atomic and nuclear reactions
1
Institute of Physics, The University of St. Petersburg, 198904 St. Petersburg, Russia
2
J.W. Goethe University, Institute for Nuclear Physics,
August Euler Str.6, 60486 Frankfurt a/M, Germany
Corresponding author: a meyer@ampc.ikf.uni-frankfurt.de
Received:
31
March
2004
Revised:
26
May
2004
Published online:
23
December
2004
A highly collimated beam of protons (≈1 MeV) entering
the channel of a monocrystal film forms at a certain depth an extremely
sharp (<0.005 nm) and relatively long (some monolayers of the
crystal) focusing area where the increase of the flux density can reach thousand
times. Impinging atoms in this focusing area can undergo nuclear or atomic
reactions with proper foreign dopants which disappear if the crystal is
tilted from this
position by only 10 radians. This effect can be called
channeling superfocusing, in contrast to the ordinary fluxpeaking
where the increase of flux density reaches only few times. Results are predicted
by quantum mechanical model calculations and confirmed
by channeling Monte Carlo simulations accounting for several properties
of the real lattice.
PACS: 61.85.+p – Channeling phenomena (blocking, energy loss, etc.) / 34.20.-b – Interatomic and intermolecular potentials and forces, potential energy surfaces for collisions / 34.70.+e – Charge transfer / 34.80.-i – Electron scattering
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004