When this picture was taken, the helium 3 neutron detector had been temporarily mounted in the still unfinished moderator. The moderator is the white, 6 inch diameter tube between the bell jar and the meters. When completed, it will contain almost 20 pounds of paraffin.
Update: See Equipment/Supplies Pg 6 for a picture of the detector installed in the completed paraffin moderator.
Two capacitive manometer vacuum gauges can be seen, both with a range of zero to .1 Torr. When the picture was taken, the cable to the MKS Baratron (below and to the left of the bell jar) was not connected. It is measuring the pressure within the bell jar itself.
The Boc Edwards Barocel unit (partially blocking the view of the bell jar) is measuring the pressure at the inlet of the diffusion pump, before the throttling valve.
The outlet of the Veeco diffusion pump is shown connected to the inlet of the 2 stage Leybold D16a vane-type pump.
Alex's hand is on the Variac which controls the fusor voltage.
The tube is connected to 6 feet of .005 in ID capillary tubing, then to a shutoff valve at the fusor.
V= 15.2 KV I= 8.5 mA P= 12.38 microns Count: 437
V= 15.1 KV I= 8.6 mA P= 12.52 microns Count: 414
V= 15.2 KV I= 8.4 mA P= 12.44 microns Count: 463
V= 15.5 KV I= 8.2 mA P= 12.4 microns Count: 445
V= 15.4 KV I= 8.4 mA P= 12.27 microns Count: 424
V= 15.2 KV I= 8.5 mA P= 12.38 microns Count: 437
V= 15.1 KV I= 8.6 mA P= 12.52 microns Count: 414
V= 15.2 KV I= 8.4 mA P= 12.44 microns Count: 463
V= 15.5 KV I= 8.2 mA P= 12.4 microns Count: 445
In short, our best runs were averaging around 220 counts per minute from our He3 detector, versus a background of around 16.
This corresponds to approximately 2000 neutrons per second
On July 26th, a 2-minute count of 1373 was recorded, at 18.6 KV, 3.9 mA and a pressure of 12.36 microns. This corresponds to over 5000 neutrons per second.