Volume VII–System Description
OMEGA EP Operations Manual
Page 26 of 35
The shot triggers used in the OMEGA EP system are mediated by a trigger generator/selector
unit (TG/S) that has separate modes of operation for independent or joint operations. In either mode, the
0.1-Hz signals pass through the TG/S before reaching the OMEGA EP Power Conditioning Executive
(EP-PCE) and the timing crates. When the two laser systems are operating independently, the TG/S
isolates OMEGA EP from the shot triggers produced by the MTG and generates synchronized T–10
and T–0 shot triggers under the control of the EP-PCE. These are used to trigger the power conditioning
units (PCU’s) and are provided to all other timing system users via the timing crates. In joint operations,
the OMEGA Power Conditioning Executive does not enable the shot triggers until the PCU’s in both
systems are at volt. The TG/S passes the signals from the MTG to the OMEGA EP PCU’s and other
users and produces no shot triggers of its own. The operating mode of the TG/S is controlled by the
OMEGA EP Shot Executive (EP-SE) based on the joint shot features of the Shot Request Form. In this
implementation, the optical pulses produced by the two systems are always synchronized with each other.
In the independent mode, each system functions as if it had an independent, dedicated timing system. In
the joint mode, the critical shot triggers originate from a single source and are shared to make the two
systems act as one. This approach allows the OMEGA optical timing fiducial to be used in OMEGA EP
and minimizes the adjustments needed to prepare for joint operations.
Table 1.4: Digital signals available at HTS crates.
Signal
Rate/Trigger
1
Diagnostic rate
2
0.1 Hz
3
5 Hz
4
T–0
5
300 Hz
6
T–10
7
30 Hz
1.
Optical Alignment
The complexity of the OMEGA EP System requires the control system be able to align Beamlines
1 and 2 to the targets in the OMEGA or OMEGA EP target chambers (TC). For the OMEGA EP target
chamber, Beams 1 and 2 may be directed to either the backlighter (port 33) or sidelighter (port 69) ports
(not visible), or after frequency conversion, to the 23º or 48º ports (deferred) assigned to them. Figure 1.14
shows a diagram of the TC and the port entry locations.
Beams 1 and 2 may also be directed to the OMEGA TC as co-aligned, but temporally offset beams.
The beams enter port H9 and travel across the chamber to the off-axis parabola inserted in port H7.
Beams 3 and 4 may only be directed to the 23º or 48º ports (deferred), shown in Fig. 1.14.
A complete list of TC port assignments is available in the System Engineering and Configuration
Requirements for OMEGA EP, S-AA-G-05 document.
Summary of Contents for Volume VII-System Description
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