Progress Towards the Production of Cryosolid HEDM Samples by Laser Ablation and Matrix Isolation Techniques
Abstract
We report a newly developed method for rapid in-vacuum deposition of thick solid parahydrogen (pH2) samples which are remarkable for their excellent optical qualities. These experiments were driven by the technological requirement of scaling up HEDM sample production while retaining the desirable aspects of the matrix isolation method for introducing energetic dopants (simplicity, versatility, etc.). The scientific result is a pronounced improvement in the quality of spectroscopic information obtained from these millimeters thick pH2 samples. Infrared absorption spectra of pure pH2 samples suggests a hexagonal close-packed (hcp) microscopic structure. The excellent optical and thermal properties suggest an overall polycrystalline structure, with large (^ 1 mm?) crystallites. We have obtained clean, reproducible spectra of the 200-220 nm electronic absorptions of B atoms in pH2. We have observed the infrared (IR) absorptions of several molecular species produced either directly by ablation (e.g., carbon clusters) or by reactions with the matrix host. We have also observed a variety of novel induced IR absorptions of the pH2 matrix host itself; transitions induced by the presence of atoms, molecules, and ions. These results constitute the most important scientific and technological advances achieved by our group over the past few years. We expect significant impacts both on the field of condensed phase spectroscopy, and on the prospects of producing useful quantities of HEDM doped cryosolid propellants.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 24, 1998
- Accession Number
- ADA397945
Entities
People
- Mario E. Fajardo
- Michel Macler
- Simon Tam
Organizations
- Air Force Research Laboratory