A new interferometer to measure preheat in laser targets
- Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States)
Many interferometer designs exist to measure the distance change through a fringe displacement. Different interferometers were used to measure the movement of the backside of a heated foil in laser plasma interactions. However, when a laser heated target sits in the middle of a target chamber with noise from pumps and other sources of vibrations, the fringes become difficult to observe and align. We have built a differential interferometer where the light paths in each arm of the interferometer retrace each other, hence making the fringes much less sensitive to vibrations than a regular interferometer. This allows the main part of the interferometer to sit outside the vacuum chamber, where it is easy to align. The final focusing element resides close to the target and collects a significant amount of the scattered light. In this investigation we will use the interferometer to measure the expansion of the backside of a preheated target in the TRIDENT chamber. Using the coefficient of linear expansion, the heat capacity of the material, and the expansion distance, we estimate a time dependent preheat temperature of the target.
- OSTI ID:
- 328546
- Report Number(s):
- CONF-980605-; ISSN 0034-6748; TRN: 99:003866
- Journal Information:
- Review of Scientific Instruments, Vol. 70, Issue 1; Conference: 12. topical conference on high-temperature plasma diagnostics, Princeton, NJ (United States), 7-11 Jun 1998; Other Information: PBD: Jan 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurement of preheating due to radiation and nonlocal electron heat transport in laser-irradiated targets
Interferometric characterization of cryogenic targets in a laser-fusion target chamber