Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 82.40  (6)
  • 82.20  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 42 (1987), S. 167-172 
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60.Kg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new working molecule 1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)-propane-2-t (CF3)3CT, is reported for the isotope separation of tritium by TEA CO2-laser-induced multiphoton dissociation (MPD). Selective and efficient dissociation of (CF3)3CT was observed by irradiation at about 980 cm−1 where (CF3)3CH was nearly transparent. The critical fluence for dissociation of (CF3)3CT at 10R(28) 980.9 cm−1 was estimated to be as low as 4.6 J/cm2, which is the lowest of the tritiated halocarbons that we have ever reported. A detailed study was made of the pressure dependence of the dissociation rate constants for (CF3)3CT and (CF3)3CH to clarify the collisional effects in their MPD. The hydrogen isotope exchange between (CF3)3CH and HTO was found to be extremely rapid, which is advantageous in the practical laser separation cycle for tritium removal from water.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 33 (1984), S. 83-90 
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Tritium isotope separation by CO2-laser induced multiphoton dissociation of CTF3 is investigated. For the optimization of the performance of this working substance, trifluoromethane, the conditions to yield high-selectivity at high-operating pressure and low-critical fluence for complete dissociation are studied using our deconvolution procedure. The irradiation conditions are varied over the following ranges; wavenumber: 1052–1087 cm−1, gas temperature: 25°C to −78°C, CHF3 pressure: 5–205 Torr. The selectivities exceeding 104 are observed for 85–205 Torr CHF3 at −78°C by the irradiation at 1057 cm−1.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Isotope separation of tritium from deuterium in heavy water was attempted by CO2-laser-induced, highly-selective multiphoton dissociation of C2TF5 present in C2DF5. Single-step T/D separation factors exceeding 3000, 1000, and 500 were attained, respectively, for the first time with CO2 laser 10P(34) 931.0 cm−1 at 10, 20, and 30 Torr pentafluoroethane pressures at −78 °C (i.e., equivalent to 15, 30, and 45 Torr at room temperature).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 28 (1982), S. 341-348 
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Isotope separation of tritium by CO2 laser-induced multiphoton dissociation (MPD) of C2TF5 is reported for the first time. The MPD spectrum obtained for C2TF5 comprised a broad peak at about 940 cm−1 where C2HF5 was nearly transparent. The unimolecular dissociation of C2TF5 was induced with much lower laser fluence than that for CTF3, another working molecule we proposed for laser isotope separation of tritium. The mechanisms and kinetics of the dissociation of C2TF5 and C2HF5 were investigated under various experimental conditions: laser frequency, pulse energy, pulse duration, tritium concentration, sample pressure, buffer gas pressure and irradiation geometry. Single-step separation factors exceeding 500 were achieved with the most efficientP(20) line in 00o–10o0 transition at 944.2 cm−1.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0649
    Keywords: 82.20 ; 82.50
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The product branching ratio was studied in relation to the radical scrambling mechanism of laser isotope separation of uranium. A mixture of UF6/CH4/Ar was irradiated either using a low-intensity cw-UV source (high-pressure Hg lamp, 250 nm ∼ 400 nm) or using high-intensity pulsed UV lasers (4th-harmonic YAG laser at 266 nm or KrF laser at 248 nm) in a supersonic nozzle reactor. While the latter gave a higher C2H6/CH3F ratio in the photoproduct than the former, the C2H6/CH3F branching ratio was found to disagree with the results reported in a static cell experiment. This anomaly in the results obtained using a supersonic nozzle reactor was well represented by a model proposed in this study which assumed no mixing before a shock wave zone and sufficient mixing after it, leading to complete suppression of radical recombination.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 37 (1985), S. 67-72 
    ISSN: 1432-0649
    Keywords: 82.50 ; 82.40 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new working molecule 2-bromo-1,1,1,2-tetrafluoroethane is reported for laser isotope separation of tritium. The multiphoton dissociation rate of CF3CTBrF is studied as a function of irradiation wavenumber, using a CO2 or NH3 laser. In a tightly focused irradiation geometry where the dissociation saturates both for CF3CTBrF and CF3CHBrF, their threshold fluences of dissociation and the geometrically biased selectivity are measured near the maximum of the dissociation rate of CF3CTBrF. When the irradiation geometry is optimized, a high selectivity exceeding 2700 is obtained.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 62 (1996), S. 373-379 
    ISSN: 1432-0630
    Keywords: 81.40 ; 82.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract It was demonstrated experimentally for the first time that particle growth of photoproduced UFS was enhanced by ionizing radiation from an α-emitting241Am source. A gas mixture of UF6, CH4, and Ar in a reaction cell was irradiated with a single shot of a KrF laser at 248 nm to form UF5 particles. Transmission electron microscope images of the samples indicated that the average size of UF5 particles produced without the α-ray source was independent of the laser energy. UFS particles produced with the α-ray source were found to be much larger in size than those produced without the a-ray source, and the enhancement of particle growth was marked when the laser energy was low. An explanation was attempted for the anomalous behaviors of particle size distribution from the viewpoint of competition between the second-order coagulation rate and the rate of diffusion from the reaction zone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...