The JRM Photo Gallery - Glowing Tubes

The picopulse project is attempting to create ultrashort ion pulses by focusing an ultrashort laser pulse inside of our Tandem. To prevent the newborn ions from being swept away by the electron-suppressing off-axis fields in our beam tubes,we swapped the existing #3 Dowlish spiral tube for an old, #1 HVEC inclined field tube. We then aligned the laser, and generated a beautiful red glow in the tubes from the scattered light.

Each thumbnail below links to a much larger image about 275 kB in size.

The high-power laser beam was fired down the tube, and the mirror was aligned to focus the beam right in the center.	The extreme intensity of the laser at the focus ionizes whatever poor gas molecules happen to be in the way. In the open air, it is particularly dramatic.
Pretty lights...	The end of the inclined field tube as it usually looks.	Looking down the bore of the inclined field tube. The mirror deployment mechanism is to the left.
The first twenty-some electrodes of the inclined field tube provide a wide aperture and flat electric field.	The electrodes that follow, with the oval apertures, are inclined to deflect parasitic electrons.