Volume VII–System Description
OMEGA EP Operations Manual
Page 2 of 35
beams copropagate into the OMEGA target chamber but can be pointed and focused to different locations
within ~1 mm.
(b)
Fast-ignition studies in the existing 60-beam OMEGA target chamber
The two compressed beams will be transported to the existing OMEGA target chamber as coaxial
beams with a common focus. The first beam will be used to make a channel in the plasma atmosphere
surrounding the target through which the second (~5- to ~20-ps ignitor) beam, will propagate to the
high-density region in the target before depositing its energy, via energetic electrons, in the compressed
core, heating the plasma and increasing the fusion yield. Using the OMEGA EP beams, LLE will be
uniquely able to study aspects of the fast-ignition approach to ICF because of the high areal densities
and high electrical conductivity of compressed DT available with OMEGA’s cryogenic capability.
Recent work
has shown that the fast-electron beam integrity in high-intensity laser–target interactions
of the target improves with increased electrical conductivity. No experiment to date has a target with
conductivity within an order of magnitude of that of a DT plasma. Fast ignition could increase the
utility of compression facilities for inertial fusion energy (IFE) research. Research activities will be
Table 1.1: Possible configurations for the four OMEGA EP beams in compressed
(short) pulse or long-pulse applications. Pulse-width limitations result
from design choices or by the
B
-integral of the beam combiner optic at
the end of the pulse compressor.
Co-propagating beams
Beam path
Compressor
§
OMEGA
OMEGA EP
OMEGA EP
Compression
Upper
1 to 100 ps
Backlighter port
1 to 100 ps
Backlighter port
1 to 100 ps
Lower
20
*
to 100 ps Backlighter port
20* to 100 ps
Sidelighter port
1 to 100 ps
Beamline
Frequency
conversion
1
~
to 3
~
1
23
°
port (1 to 10 ns)
48
°
port (future)
2
23
°
port (1 to 10 ns)
48
°
port (future)
3
23
°
port (1 to 10 ns)
48
°
port (future)
4
23
°
port (1 to 10 ns)
48
°
port (future)
§
Beamline 1 or 2 into either pulse compressor.
*
Beams in the lower compressor are limited in energy or pulse width by the B-integral of a
beam combiner optic: a 20-ps pulse width is typical for most applications.
Summary of Contents for Volume VII-System Description
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