Creating X-rays with a standard vacuum tube

TL;DR

Operated vacuum tube in cold cathode mode to produce x-rays, faced challenges with breakdowns and detected fluorescence using Geiger counter.

Transcript

hey everyone I thought I'd play with some x-rays tonight so I got ahold of a RCA 8:11 a vacuum tube and I hooked it up to my high-voltage supplies this is a 30 kilovolt at up to 300 micro amp power supply and I'm going to operate this in sort of cold cathode mode so the problem with turning on the filament using a filament voltage of 3 to 6 volts t... Read More

Key Insights

• 😰 Operating a vacuum tube in cold cathode mode allows for higher voltage and efficient x-ray production.
• 🥺 Breakdown issues inside the tube can lead to pulsing during operation.
• 📤 Insulator surfaces and electrode placement play crucial roles in preventing arcing and maintaining x-ray production.

Questions & Answers

Q: How does operating a vacuum tube in cold cathode mode differ from using it with a filament?

Operating the vacuum tube in cold cathode mode allows for higher voltage to accelerate electrons, producing x-rays, while using a filament hinders voltage buildup due to excessive current flow.

Q: Why does the tube experience breakdowns leading to pulsing during operation?

Breakdowns occur inside the tube due to arcing over insulator surfaces, causing power supply overload and pulsing of x-ray emission.

Q: Why is it essential to have electrodes on opposite sides of an x-ray tube?

Electrodes separated on opposite sides prevent arcing across surfaces inside the tube, reducing the risk of breakdowns and maintaining x-ray production efficiency.

Q: How did the experiment demonstrate the fluorescence of the tube glass versus the image intensifying screen?

The experiment showed that most x-ray energy was lost in the glass of the tube itself, with minimal fluorescence observed in the intensifying screen due to energy dissipation.

Summary & Key Takeaways

• Operated RCA vacuum tube at 30 kilovolts in cold cathode mode to produce x-rays.

• Used medical x-ray screen to detect x-rays emitted from the tube.

• Observed fluorescence in tube glass rather than the screen, faced breakdown issues causing pulsing.