Biomedical subjects

N J Fisch

Publications and source records attributed to N J Fisch.

21 records · Page 2Linked to original sources

PubMed2000

Stability of muon beams to Langmuir waves during ionization cooling.

Fast cooling of muon beams will be needed for building either TeV muon colliders that might explore the electroweak gauge symmetry breaking or muon storage rings that could become ultrabright neutrino sources. Stochastic and electron cooling take longer than the muon lifetime, so attention has been focused on the potentially faster but less explored ionization cooling. Addressing recent concerns that excitation of Langmuir waves might be deleterious for ionization cooling techniques, we show that, while the hydrodynamic instability indeed might be dangerous, the waves are, in fact, stabilized through a combination of resistive and kinetic effects at a very modest emittance of the beam.

Journal Article↗

PubMed2000

Stimulated raman scattering of rapidly amplified short laser pulses.

The theory of transient forward stimulated Raman scattering (FSRS) of rapidly amplified short laser pulses is put forth to complement the classical theory for FSRS of stationary pulses. Quantitative conditions for FSRS suppression are identified. In particular, it is shown quantitatively how the limitation imposed by pumped pulse FSRS on the output laser intensity in plasma-based ultrapowerful backward Raman amplifiers can be overcome through a selective detuning of the Stokes resonance.

Journal Article↗

PubMed1999

Generation of periodic accelerating structures in plasma by colliding laser pulses.

A mechanism for generating large (>1 GeV/m) accelerating wakes in a plasma is proposed. Two slightly detuned counterpropagating laser beams, an ultrashort timing pulse and a long pump, exchange photons and deposit the recoil momentum in plasma electrons. This produces a localized region of electron current, which acts as a virtual electron beam, inducing intense plasma wakes with phase velocity equal to the group velocity of the short pulse. Modulating the pumping beam generates periodic accelerating structures in the plasma ("plasma linac") which can be used for particle acceleration unlimited by the dephasing between the particles and the wake. An important difference between this type of plasma accelerator and the conventional wakefield accelerators is that this type can be achieved with laser intensities I<<10(18) W/cm(2).

Journal Article↗