Search found 142 matches

by George Dowell
Thu Feb 07, 2013 8:36 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

<t>Yes there are still texts that try to distinguish X-Rays from Gamma rays by their position on the spectrum chart, not by their origin. If you talk to Dr. Gordon Gilmore, you better call say annihilation radiation by its real name not X-Rays!<br/> <br/> In the case of X-Ray generators, in my humbl...
by George Dowell
Thu Feb 07, 2013 7:05 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

<t>John Cuthbert wrote:<br/> > I'm fairly sure that most of what Dr Roentgen named X rays were what would later be classified as bremstralung, but that didn't stop them being X rays any more than light isn't light if it didn't come from the sun.<br/> <br/> Yes actually it does John if we are to be a...
by George Dowell
Thu Feb 07, 2013 7:36 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

<t>Correct Chris, that's caused by electron Bremsstrahlung. <br/> <br/> It is not exactly an X-Ray by definition, it is Bremsstrahlung radiation, but ionizing photon radiation nonetheless. Photon's are often called by the manner of their origin, i.e. X-Rays, Gamma Rays, Annihilation Radiation,Bremss...
by George Dowell
Thu Feb 07, 2013 6:43 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

<t>By the way a tungsten target does not turn on until above 59 keV (tungsten K edge) . A real X-Ray tube designed to work at lower HV would have an MO or copper target. Or in the case of a fusor, a very large iron target. A peak of about 6 keV would result, with a background of Bremsstrahlung from ...
by George Dowell
Thu Feb 07, 2013 6:34 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

Richard, may I ask what you measured the 100 mR/H with? A low energy intergrating ion chamber I assume? George Dowell
by George Dowell
Wed Feb 06, 2013 12:37 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

<t>RadPro Calculator- Fooling around with dose at 10 cm from a 30 kVp 10 Ma <br/> X-Ray source, shielded by iron or lead.<br/> <br/> Dose at 10 cm with 2mm Iron shielding (fusor chamber? = 5 R/H<br/> <br/> Dose at 10 cm with 2mm Pb shielding = 1 10E-21<br/> <br/> It takes little effort to shield 30 ...
by George Dowell
Sat Feb 02, 2013 4:41 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: NaI(Tl) + PMT which bicron preamp ?
Replies: 5
Views: 2580

Re: NaI(Tl) + PMT which bicron preamp ?

<r>Helllo.<br/> <br/> I don't think you need a preamp to drive the soundcard. Most are using a simple <br/> passive integrator (resistor+capacitor).<br/> <br/> If you wish I can send you links direct.<br/> <br/> PS the second Bicron is way overkill ( too powerful). It is a charge sensitive preamp fo...
by George Dowell
Sun Dec 16, 2012 4:28 am
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - X-ray radiation!!
Replies: 41
Views: 27783

Re: FAQ - X-ray radiation!!

<t>Unfortunately the housing on pen dosimeters limit their low end response. Even the latest technology using conductive plastic instead of metal housings is pretty puny below 16 keV. Those low energy rays are the very ones absorbed by the skin.<br/> <br/> Energy response chart encloed. <br/> <br/> ...
by George Dowell
Mon Oct 29, 2012 3:44 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: ISMTR-5 at MURR
Replies: 3
Views: 1708

Re: ISMTR-5 at MURR

<t>Ditto my feelings Jim.<br/> <br/> My first blue glow was in 1965 at Rola School of Mines in Rolla MO.<br/> <br/> That very day I made a life changing career decision and went into electronics instead of nucleonics, in a support roll. Worked out OK, as now I have time to do and study what I want t...
by George Dowell
Fri Oct 26, 2012 9:26 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: What's wrong with this NaI(Tl) crystal?
Replies: 5
Views: 2696

Re: What's wrong with this NaI(Tl) crystal?

<t>My advice is to mount it to a PMT with good quality optical coupling compound, a high current dynode string, a stable HV supply- and test the FWHM for quality. Crystals that look perfect to the eye sometimes don't pass, others you would never think, give good results.<br/> Good for amateur work a...