Liquid Argon Purity

Liquid Argon pollution studies after neutron radiation have been conducted on various parts of the EM calorimeter including the barrel summing and mother boards. These tests were conducted at the SARA facility in Grenoble. The tests and the observations made have been described in the following two notes:

• Pollution of liquid argon after neutron radiation measured at SARA
  
  
• Pollution of liquid Argon after irradiation of various calorimeter parts with fast neutrons
  

The samples were exposed to an equivalent of a 10 year irradiation at LHC. The amount of impurities is monitored using an alpha-cell. The tests have demonstrated that there is no evidence for emission of oxygen. In the EM barrel, the loss of signal due to any other impurities should be well below 1.5% after 10 years.