Figure 1

The experimental setup is shown where a $1\omega$ high-power (1-ns square) laser beam initially heats a narrow $200\mu \mathrm{m}$ plasma channel in ${\mathrm{N}}_2$ gas injected by a 1.5 mm nozzle. Two solenoids produce a uniform high magnetic field ($B=12\mathrm{Tesla}$) parallel to the heater beam. A collective Thomson-scattering diagnostic measures the electron temperature profile perpendicular to the heater beam using a low power $2\omega$ probe; a spectrometer slit is imaged perpendicular to the heater beam to collect light scattered from the low energy $2\omega$ probe laser.Reuse & Permissions

Figure 2

Spatially resolved Thomson-scattering spectra are presented for conditions: (a) without an external magnetic field ($B=0\mathrm{T}$) near the end of the heating pulse and (b) with a high magnetic field ($B=12\mathrm{T}$), 500 ps after the end of the heater; the magnetic field reduces the spatial extent of the plasma and increases the electron temperature by a factor of 4. The spectra near the center of the heated region are shown for both conditions (c) $B=0\mathrm{T}$ ($T_e=210\mathrm{eV}$), (d) $B=12\mathrm{T}$ ($T_e=800\mathrm{eV}$); data are fit with a form factor to determine the electron temperatures from the separation between the spectral features.Reuse & Permissions

Figure 3

A series of measured electron temperature profiles (a) 1.0 ns, (b) 1.6 ns, (c) 2.1 ns are compared to the simulated temperatures using the Braginskii model (curves) showing that the heat wave has been localized by a $B=12\mathrm{T}$ magnetic field.Reuse & Permissions

Figure 4

(a) The electron temperature profiles for no magnetic field (triangles) and an externally applied field of 12 Tesla (squares) show an increase in peak electron temperature and a corresponding reduction in the propagation of the heat wave perpendicular to the magnetic field lines. LASNEX simulations with an imposed self-consistent magnetic field reproduce the experimental results (solid-curve) when high external magnetic fields are applied. When no magnetic filed is imposed, a nonlocal model is required and reproduces the results (dashed-curve). (b) Comparison of the Braginskii model (curve) agrees well with the peak electron temperature measured (squares) when the maximum external magnetic field is applied ($B=12\mathrm{T}$). For low magnetic field conditions, $B=0\mathrm{T}$ and $B=4\mathrm{T}$, the model differs from the measurements indicating that nonlocal effects are important.Reuse & Permissions