Shock Timing

Platform Purpose

The shock timing experiments planned by the Capsule Tuning Integrated Experimental Team (IET) are the first cryogenic shock timing experiments in a series of sub-campaigns with the goal of tuning the ignition hohlraum and capsule design for ignition experiments in 2010. The experiments require 192 beams smoothed with continuous phase plates (CPPs), smoothing by spectral dispersion (SSD), and polarization smoothing (PS). Two types of cryogenic hohlraum with deuterium-filled capsules equipped with a re-entrant cone will be used.

These shots are to set the shock speed and timing in the cryogenic fuel of an ignition capsule by using capsules with liquid D2 as emulators. For shocks driven by radiation temperatures below about 180 eV, the Velocity Interferometer System for Any Reflector (VISAR) reflection off the shock front in D2 will be used. For shocks driven by radiation temperatures >180 eV, the Streaked Optical Pyrometer (SOP) will be used to measure the break-out time of the shock through a re-entrant Au witness plate. In addition, the Dante spectrometer will be used to infer the strength of the first shock from the rise in radiation temperature.

Laser and Target Configuration

The laser and target configurations for this platform are summarized below:

Target	# beams	Laser energy/Pulse width
Au:B hohlraum, cryogenic, H-He gas fill	192	160-kJ, 14-nsec shaped pulse
Au:B-lined U hohlraum, cryogenic, H-He gas fill	192	750-kJ, 15-nsec shaped pulse
Au:B hohlraum, cryogenic, H-He gas fill	192	160-kJ, 14-nsec shaped pulse
Au:B-lined U hohlraum, cryogenic, H-He gas fill	192	750-kJ, 15-nsec shaped pulse

Hohlraums will be "Scale 1.07" . Dimensions for this hohlraum are summarized below:

Target	Hohlraum Length	Hohlraum width	Laser Entrance Hole (LEH)
Scale 1.07	10.01 mm	5.44 mm	3.01 mm

The laser will employ PS and SSD, with a nominal bandwidth of 60 GHz for the latter. A 2-color wavelength detuning, typically 0.5Å between inner and outer cones will also be required. Additional detailed modifications to the laser and target will be made to suit the needs of particular experiments.

A generic experimental configuration is shown below:

Diagnostic Configuration

Standard diagnostics for this platform and their location (elevation, azimuth) are provided below. See Chamber Geometry and Diagnostics for additional information.

Diagnostic	Location
VISAR/SOP	DIM 90-315
Dante-1	Fixed (143-274)
FABS/NBI	Q31B, Q36B
FFLEX	Fixed (90-110)
SXI, Top/Bottom	Fixed ((18-123),(161-326))

For further information on scientific opportunities at the NIF, please contact:
Dr. Christopher J. Keane, LLNL
PHONE: (925) 422-2179
E-MAIL: Contact us