6.3 Understanding the NIF DLI Interaction Volume

The NIF DLI interaction volume begins at the entrance to the target vessel and extends to the back of the target vessel. The beams cross at a 7.8⁰ angle with respect to each other. Examples of the beam overlap at various positions within the target volume are shown in Figure 8. Units of the plots are mm. The interaction plane is the plane at which the two beams overlap each other (maximum overlap integral). Negative distances are toward the NIF laser and positive distances are toward the rear of the target vessel.

If fluence uniformity is a concern for your experiment, please contact the laser scientist for NIF DLI to discuss and obtain near-field images of the laser beams from previous experiments to determine the illumination profile that would be incident onto your chosen target.

Simulated fluence profiles at multiple locations within the DLI target vessel demonstrating the change in beam overlap away from the Target Interaction Plane
Figure 8. Simulated fluence profiles at multiple locations within the DLI target vessel demonstrating the change in beam overlap away from the Target Interaction Plane (TIP): at TIP (left), 15 cm in front of TIP (middle), 30 cm behind TIP (right).