Instrument Troubleshooting, Feeding the Magnet

Instrument Troubleshooting

Cosmic ray instruments are complex and it seems there is always something that needs adjusting or fixing or calibrating, and then testing and confirming and re-calibrating.  This is what consumed our time while waiting for the wind to die down.  And it is a good thing to have had that time to do those last ground tests, because we encountered a troubling condition—an intermittent false trigger.  

Continue reading

Cathode Rays

The 100th anniversary of the cathode ray tube.

This is the first of three posts describing a now-(nearly)-obsolete technology.

Thomas Edison nearly discovered them.  In his experiments with heated filaments in evacuated glass bulbs trying to find a suitable incandescent lamp, there were hints.  He noticed depositions of material on the walls of the glass tubes.  Many scientific discoveries are preceded not by the expression “Eureka”, but instead by the comment: “Hmm, that’s funny”.  If he had followed up on this odd result, he might have also invented the vacuum tube amplifier.

Continue reading