Lab Pictures 10

March 1, 2009;

       NCSU, Raleigh and TUNL, Duke, Durham NC

At the end of the last gallery I showed spray painting the sphere to avoid dusty ceramic; however the earlier layers of clay did not adhere well enough to itself to withstand the slight shrinkage of this hard boron nitride (BN) paint, and so afterwards I had to take it all off down to the metal and spray with the BN paint, shown below.

Also there has been some problems with the homemade connectors that link the coax from the magnetrons to the antennas. I filled them with hot glue, which is very easy to not only make but also disassemble. However sometimes the surface would ignite and make a real mess. Thus I've added a layer of porcelain and coated that with BN paint.

Finally after months of anticipation and preparation, the experiment moved to the Triangle Universities Nuclear Laboratory (TUNL) at Duke University, about a half hour drive away. This is necessary because the goal of the device is to generate neutrons from deuterium via fusion reactions; even a modest success could be dangerous and thus the reactor must be run in a place with good shielding. I have the electronics and controls in one room and feed cables through a thick wall to the target room, used for TUNL's 10 MV accelerator. When time comes to run with deuterium, TUNL has very good equipment for measuring any neutrons that might be produced. I am also concerned with x-rays since the aluminum sphere is essentially transparent to anything over about 30 kV.



Soaking the old ceramic

Had to peel/grind off the old coating

Bare metal

Prepped for spraying with BN paint

New antenna seals

Feedthroughs for the antennas has been very difficult; these screw in from the inside and seal with o-rings

Close-up of new seal

1/4 inch aluminum with slot for o-ring

SS washers

These are the smooth face for the o-ring seals

Rounding edges

Need to avoid large electric fields on corners

BN on connectors

These homemade microwave connectors, filled with hot glue, have been failing from time to time; with BN coating I hope they will last

Close up of connector

These have to handle 1000 W

Dr. David Aspnes loading van

Dave is my faculty advisor; this is the first trip to TUNL at Duke, Feb. 12, taking the electronics rack

Second trip to TUNL

Loading at NCSU one of the hemispheres

Loading drama

Tight fit!

Even without cap banks and pumps etc. it is a big job

Heave ho

Nick Stoute lends a hand

Don't crush the physicist

Gravity assist

John Dunham helps wheel a hemisphere

Landing at TUNL, into the bowels of the building

Through the target room door

Big door on tracks that shields from any neutrons produced

Second trip with another hemisphere, in the van

Setup in the target room

Target room

North hemisphere without antennas

shows washers that press against the o-rings for seal

South hemisphere with grid

The dark patch is the south window with a microwave grid over thick lead glass in front of 1/4 inch lexan

North hemisphere with antennas

Complete South half

me with reactor assembled

All plugged in

Me and complete reactor

Target room workspace