• Transcribe
  • Translate

James A. Van Allen journal, October 1955-March 1958

Page 147

More information
  • digital collection
  • archival collection guide
  • transcription tips
 
Saving...
A special virtue of these crystals is the fact that they can be exposed bare to the atmosphere, though they are, of course photo-sensitive and must be shielded from light. He is considering them for the direct detection of the auroral particles. Has observed as high as 1000/1 signal/noise ratio for Po alpha's. More typically 100/1. Get ~ 0.2 volt signal. Therefore Noise level may be as low as ~5 kilovolts ! Can be obtained in only quite small sizes (~ 2mm square) but such a size is quite adequate for the purpose ((~10 exponent 7) / (cm exponent 2)( second))
 
Van Allen Papers