INDEX OF REFRACTION AND DISPERSION OF SEVERAL GASES IN CERENKOV COUNTER USE

Technical Report · Fri Dec 01 04:00:00 EST 1961

DOI:https://doi.org/10.2172/4731864· OSTI ID:4731864

Niederer, J A

Measurements of index of refraction as a function of gas pressure for carbon dioxide, ethane, methane, sulfur hexafluoride, Freon 13, Freon 14, and Freon 23, which are suitable for Cerenkov Counter use, are reported. These gases do not react with Al or Ag mirror coatings, or other materials used in such counters, and have indices of refraction that are large enough to permit the use of these gases at reasonable pressures. Methane and ethane are both toxic and highly explosive; the remainder of the group listed are non-toxic and very stable. Carbon dioxide appears to be the most suitable gas of this group for a precise determination of high energy particle velocity in a Cerenkov Counter from pressure-refractive index calibration data. Data indicate that methane and ethane have the highest dispersion of the gases of this group and Freon 23 has the lowest. Dispersion is a more serious limitation to ultimate Cerenkov counter resolution at very high energies than is muitiple scattering. In some Cerenkov Counter uses, a minimum of particle attenuation may be desirable; methane offers the smallest nuclear cross section of these gases. Carbon dioxide does not present major difficulties in attenuation or multiple scattering, and its dispersion appears to permit acceptable Cerenkov angular resolution within the range of particle energies encountered in AGS operation. (H.G.G.)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• DOE Contract Number: AT(30-2)-GEN-16
• NSA Number: NSA-17-018591
• OSTI ID: 4731864
• Report Number(s): BNL-6889
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM
CARBON DIOXIDE
CHEMICAL REACTIONS
CHERENKOV COUNTERS
CHLORINATED HYDROCARBONS
COATING
DISPERSIONS
ELEMENTARY PARTICLES
ENERGY
ETHANE
EXPLOSIVES
FLUORINATED HYDROCARBONS
FREONS
GASES
INSTRUMENTS AND INSTRUMENTATION
METHANE
PRESSURE
QUANTITATIVE ANALYSIS
REFRACTION
SCATTERING
SILVER
STABILITY
SULFUR FLUORIDES
TOXICITY