Physics of mag tapes

[Paul Pangaro <pan%athena.pangaro.dialnet.symbolics.com@RELAY.CS.NET>]

  I have been taking cart tapes for SMBX in and out of airport
  security for years now, and sometimes with the same tape a dozen
  times. Coming back from Boston recently I was met with shock from
  the security-person that I was doing this, because "everybody
  else passes them through by hand" and not through the x-ray
  machine.
  
  Anyone really know what those things do, and whether it can, over
  repeated exposures, affect the oxide/fields on the tape?  I
  realize "it is probably better to be safe than sorry" but I was
  curious about the known realities here.
  
  Best,
  PANgaro