5.4 The Surface

A polished MgO surface (10mm x 10mm) with a (100) orientation was used. The surface had a maximum surface roughness R\( _{rms} \) of less than 5nm (1nm typically) as specified by the supplier Mateck [7]. The sample was stored in a sealed container as provided by the supplier. After incorporation into the JUSO apparatus a pressure in the 10\( ^{-9} \)mbar range was achieved. The sample was also heated to 150 \ensuremath{}C for several hours to clean the surface. No sputtering of the surface with heavy noble gases was done.

March 2001 - Martin Wieser, Physikalisches Institut, University of Berne, Switzerland