Wednesday, July 14th, 2010:

   Our newest products this month are Crookes Tubes. Crookes Tubes are early experimental electrical discharge tubes that were invented by British physicist William Crookes. These high vacuum tubes produce an impressive array of high voltage effects in a vacuum. They come in a variety of different configurations; demonstrating cathode rays, x-rays, ionization and the behavior of electrons.
  The tubes are evacuated to a very low pressure (7x10-4 to 4x10-5 torr) and when a high voltage is applied to the electrodes (typically  from 5 to 100 kilovolts) they produce a dramatic display. These tubes are great for classroom or science fair demonstrations.
They are permanently sealed and ready to use, only requiring a high voltage power supply to operate. See our High Voltage Equipment page for more information & pricing.
Here's a few images: