Oscilloscope X-Y Test

This is a video of our display oscilloscope being tested in X-Y mode. The signal of a .wav file is being fed (left to Y and right to X) through the audio card of my laptop to the oscilloscope. Pretty cool...

Einzel Lens Model

These images are of a 3d model for our einzel lens. The lenses must be custom fitted for copper pipe. Since our copper pipe is held at ground, only the middle cylinder needs to have an electrical connection.

Electrical Feed-throughs

Today we drilled and tapped our 12 electrical feed-throughs. We are using spark plugs because they are heavily insulated and are designed to pass electrical connections into a vacuum.

Vacuum System - Roughing Pump

Today we reached a huge milestone in our project by testing the vacuum system.  We only tested the roughing pump because we didn't have access to liquid nitrogen which we need for the diffusion pump.  The test went wonderfully. In fact, the roughing pump outperformed our expectations by getting the pressure in the vacuum chamber down to about 10^-4 torr.

High Voltage Power Supply & Analog Voltmeter

This video shows both a working analog voltmeter and a working power supply. We acquired this P.S. for 24 dollars off of ebay, so we were unsure whether or not it would be suitable for our purposes. The power supply takes a 24 volt DC input and outputs a high voltage DC, but an external circuit is required to control the output voltage. A potentiometer is used to scale the output voltage with a 1:1000 ratio. When I turn the potentiometer, I change the resistance and thereby change the voltage that enters the power supply's control circuit. When the resistance is high (max 5k ohm) the voltage is 0, and the high voltage output is 0. Inversely, if the resistance is low, the voltage is 15 volts, and the high voltage output is 15kv.

The analog voltmeter runs off of lower voltage than the high voltage output, and therefore, ten 1Mohm and one 10k ohm resistors are strung together in series from the positive side of the high voltage output. The meter reads the voltage across the 10k ohm resistor by powering an electromagnet that moves the needle accordingly.

Eye Protection is Key

Always use eye protection when cutting... Even if the only available eye-wear is a scuba diving mask. This video is of Harry cutting into the SEM's desk mount to create the diffusion pump and baffle feed-through.

High Voltage Power Supply Flame Test

When I plug in the 24 v dc power supply, the voltage is stepped up to as high as 15kv. (adjustable from 0 to 15kv).  The high voltage leads are connected to metal plates and are situated (precariously) parallel to one another. This allows for an electric field to be created between the two plates, thereby stretching the flame which is made up of a mixture of various ions. If you look closely at the flame, whenever I plug in the power source, the flame is stretched apart slightly. This tells us that the power supply is indeed working.

Interestingly enough, when I plugged in the power supply, the high voltage wires moved together because of the voltage difference (opposite charges attract). This shows that these old wires were not insulated with shielding, which consists of a metallic layer of insulation that blocks any potential electric field from exiting the  cable's insulation.