COZ Gas Mixture

Sense wires - 48 mkm Stablohm resistive wires - 0.6 kOhm/m

Potential wires - 127 mkm Cu/Be wires

• Argon-Ethane-Isopropanol 48-52-1 %
• Isopropanol- CH3CHOHCH3 - dissociates differently than
  ethanol - CH3CH2OH
  and methanol - CH3OH
  
  Wires from resistive alloy in the gas mixture Argon-Ethan with methanol or ethanol additives are aging very rapidly!
  Isopropanol - very important for the COZ stability during HERA running !
• Isopropanol more complex molecule with more rotational and vibrational absorption levels for quenching UV photons
  - Isopropanol should also be preferred because it is not active vapour for plastics, epoxy etc.

• negative correlation between Isopropanol content and the drift velocity - vd affected by
  the alcohol additives --- systematic measurements ?
• anode cathode separation and cathode configuration play an important role
  in electron regeneration by photons from cathode surfaces -
  wire cathode configuration reduces the probability of such photoelectron production
• COZ cathodes = surfaces ! ! !
• drift field = strips ! ! ! - further surface ! ! ! <\UL>