Atomic vapor laser isotopic process

Atomic- Vapor Laser Isotope-Separation. Although the technology has been around since the 1970s, laser isotope separation has only recently matured to the point of industrialization. In particular, laser isotope separation for the production of fuel and moderators for nuclear power generation is on the threshold of pilot-plant demonstrations in several countries. In the atomic vapor laser isotope-separation (AVLIS) process, vibrationaHy cooled U metal atoms are selectively ionized by means of a high power (1—2 kW) tunable copper vapor or dye laser operated at high (kHz) repetition rates (51,59,60). 

Atomic systems, in lasers, 74 666-669 Atomic Vapor Laser Isotope Separation (AVLIS) process, 25 416 Atomic weight, 75 748 Atomization, 77 774-775 in spray coating, 7 69-74 technology of, 23 175 Atomizer operation, concerns related to, 23 195... 

Uranium isotope enrichment by LIS has been exhaustively studied and the conceptual outlines of two separate programs have made their way into the open literature. These methods are multiphoton dissociation of UFe and LIS of monatomic uranium vapor (atomic vapor laser isotope separation, or AVLIS). AVLIS was selected by the United States DOE as the process to be used in its separation plants during the 1980s and 1990s, but, once again due to the present oversupply of separated uranium, the plant has recently been closed. 

Laser isotope separation is one area where multistep excitation and ionization has great commercial potential. The research and development efforts in atomic vapor laser enrichment of 235y are a major factor contributing to the current research activities in laser excitation and ionization processes. The first paper on selective multistep photoionization of atoms was published in 1971. (.62) Since then numerous review articles( 15, 16 >L7,63 >54, (i5) ave been written on laser isotope separation and, in each review, there is a section on atomic vapor photoionization processes. The subjects of economics and critical parameters have been well covered in previous reviews and will not be discussed in detail here. We... 

The process involves two steps an atomic beam of uranium vapor produced by electron-beam evaporation is excited by light of wavelength 4266.266 A from a pulsed laser and is subsequently ionized by light of wavelength 3609 A from a second laser. The ions produced are detected by a mass spectrometer. To achieve selectivity for the excitation process the incident wavelength must coincide exactly with one of many absorption lines of atoms. The isotope shift of the absorption lines between and near 4266 A is about 0.06 A or about 0.32 cm". Hence, the width of the laser line must be less than 0.32 cm". ... 

The Energy Research and Development Agency (ERDA), the forerunner to the DOE, through the late 1970s to 1981 supported the study of three new experimental processes for uranium enrichment. Two were based upon laser separation, and one on plasma separation. Jersey Nuclear-Avco Isotopes Incorporated (subsidiary of Exxon) and the LLNL worked on atomic uranium vapor. LLNL referred to it as AVUS. The LANL and a group at Exxon Research Laboratories (not connected with Jersey-Avco) worked on molecular UFg. TRW Incorporated pursued research work on a plasma separation process. Union Carbide Nuclear Division (UCC-ND) supported each in their efforts. In 1981, the AVLIS process at LLNL was selected as the process to be developed further and the other processes were subsequently phased out. 

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