Search found 454 matches

by Wilfried Heil
Mon Nov 30, 2009 9:31 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Nuclear weapon tampers and moderators
Replies: 25
Views: 7166

Re: Nuclear weapon tampers and moderators

Carl - looks like you've got your hands on a remnant of some of the world's earliest plutonium.
An ugly piece of history.

Anyway, congratulations on that find.
by Wilfried Heil
Wed Oct 28, 2009 6:52 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron detection with a phoswich detector
Replies: 10
Views: 4684

Re: Neutron detection with a phoswich detector

<r>Most of the scintillators are sensitive to gamma and fast neutron radiation at the same time. BaF2 has been used for gamma and neutron detection, but it only responds to neutron energies >10MeV. The key point here is that you get different pulse shapes from the scintillator for gamma electrons (s...
by Wilfried Heil
Tue Oct 27, 2009 6:24 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Tungsten Needle Observations
Replies: 13
Views: 7062

Re: Tungsten Needle Observations

<t>You tungsten needle looks like a welding rod, which usually contains an admixture of either thorium or lanthanum as a thermionic emitter.<br/> <br/> When the needle gets red hot, it starts to emit a high electron current and the voltage across the discharge drops to the point where you can't dete...
by Wilfried Heil
Tue Oct 27, 2009 3:54 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron detection with a phoswich detector
Replies: 10
Views: 4684

Re: Neutron detection with a phoswich detector

<r>You should find the best answers to your questions here: <br/> <URL url="http://www.detectors.saint-gobain.com">http://www.detectors.saint-gobain.com</URL><br/> <br/> BC-436 is a deuterated polymer that can only be made in thin layers. Otherwise it would be among the best because it is solid and ...
by Wilfried Heil
Sun Oct 25, 2009 1:54 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: lead shielding design "castle" recommendations?
Replies: 10
Views: 5666

Re: lead shielding design "castle" recommendations?

<t>We don't know what you are attempting, so it will not be possible to give proper advice.<br/> <br/> A "lead castle" normally is a shield against ambient gamma radiation for low level activity measurements, with about 2 inch thick walls and the detector and a sample to be analysed inside. It does ...
by Wilfried Heil
Sat Oct 24, 2009 12:06 am
Forum: Other Forms of Fusion - Theory, Construction, Discussion, URLs
Topic: Pulsotron-2 new device working
Replies: 30
Views: 17063

Re: Pulsotron-2 new device working

<t>These blue lines are not physically there where you see them. <br/> <br/> It is an artefact produced during image readout by the "rolling shutter" CMOS sensor in your camera, which is blinded by the spark. As you can see, the lines always move from upper left to lower right and their inclination ...
by Wilfried Heil
Sun Oct 18, 2009 6:19 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: F2 Operational
Replies: 9
Views: 4911

Re: F2 Operational

Congratulations on your progress. Quite an impressive setup.

Wilfried
by Wilfried Heil
Sun Oct 18, 2009 6:03 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Chamber design?.....
Replies: 10
Views: 7412

Re: Chamber design?.....

Josh - Viton seals instead of the copper rings will leak x-rays through the joints!
We are not using these seals on vacuum parts with HV just because of this danger.

What you have now is a rogue x-ray source in a place that looks like a classroom.
by Wilfried Heil
Fri Oct 09, 2009 11:09 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Van De Graff
Replies: 8
Views: 3405

Re: Van De Graff

To my knowledge, no one has run a fusor with a VDG yet. Of course one can discuss such things endlessly, or simply try them, which would bring the discussion to a higher level.
by Wilfried Heil
Fri Oct 09, 2009 10:46 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Van De Graff
Replies: 8
Views: 3405

Re: Van De Graff

Nope, that won't work. You might consider to use the inverter, transformer and diodes alone ...
Or just try to use the Van de Graaff as a DC power supply for the fusor and report your results.