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Geiger Tube Counts Pseudo Standard

03/28/2017 3:02 PM

Recently, one of my experimental systems, we initiated Geiger testing by the reactor, hoping to detect Beta or Gamma radiation from the experiment. We really only expect Beta radiation. We are sure that Alpha radiation cannot penetrate the reactor.

We had a connectivity glitch with interfacing the Geiger with our data logging system, and this resulted in showing 0 cpm rate. Today, my associate has reported the repair is completed. Now he is reporting a count through a paper mailer and plastic bag on Fiesta ware chips of 2500 cpm. I think Fiesta ware used Uranium glaze.

A very detailed analysis of the radiation exposures due to uranium in dinnerware can be found in the Nuclear Regulatory Commission publication “Systematic Radiological Assessment of Exemptions for Source and Byproduct Materials” (NUREG 1717). I got bogged down trying to mentally keep notes and make sense. What I seem to see is that not only is the Uranium glaze radioactive (mostly with alpha, gamma emission), with long half-life, the products of decay are also radioactive and, as such, contribute to the classes and intensity of radiation observed. Is that correct in basis?

With a Russian made SBM-20 all metal Geiger tube, we previously only saw up to 700 cpm outside the wrappings, at a distance of 1 cm from the tube. Now we are seeing approximately 2500 cpm through the wrappings at close contact. Is that about right (for gamma)? I don't see how we could be seeing alpha or beta through a shipper envelope and a plastic bag...am I just totally wrong?

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#1

Re: Geiger tube counts pseudo standard

03/28/2017 3:13 PM

"There are three principal radiation exposure pathways associated with Fiesta Ware and other uranium containing tableware:

1. Exposure to the body from the gamma rays emitted by radionuclides in the ceramic glaze

Buckley et al reported exposure rates of 0.5 and 15 mR/hr at the surface of a dinner plate and 0.002 and 0.3 mR/hr at one meter.

The following effective dose equivalent rates were reported in NUREG-1717 for the gamma rays emitted by uranium-containing dinnerware (20 % by weight uranium):

Distance 10” Plate 3.5” Cup

1 foot 6.5 x 10-4 mrem/hr 3.7 x 10-4 mrem/hr

3 feet 7.7 x 10-5 mrem/hr 4.1 x 10-5 mrem/hr

6 feet 1.9 x 10-5 mrem/hr 1.1 x 10-5 mrem/hr

2. Exposure to the hands from the beta particles emitted by radionuclides in the ceramic glaze

Using film badges, Menczer measured beta-gamma dose rates of 0.5 to 20 mrad/hr on contact with various items of glazed ceramic dinnerware. He calculated that the hands would receive approximately 2 to 10 rem per year as a result of handling such dinnerware 1.5 hours per day.

Piesch et al. measured 32 mrem per hour at the surface of a red ceramic teacup. Assuming daily use of the cup, they estimated an annual dose to the lips of 400 mrem and 1200 mrem to the fingers.

NUREG-1717 calculated the beta dose rates at a depth of 7 mg/cm2 (i.e., the nominal depth of the germinal layer of the skin) as well as the estimated effective dose equivalent. It was assumed that the source was a 10 inch diameter plate with a 20 % by weight uranium content.

Distance Dose Rate Effective Dose Equivalent Rate

Contact 24 mrad/hr 0.0024 mrem/hr

1 foot 0.84 mrad/hr 0.0021 mrem/hr

3 feet 0.089 mrad/hr 4.5 x 10-4 mrem/hr

The ratio between the effective dose equivalent rate and dose rates vary with distance because the further away from the source, the greater the area of skin that was exposed.

3. Ingestion of uranium that has leached into food that has been in contact with the ceramic glaze

Kendig and Schmidt measured uranium concentrations of 1.8 to 8.6 ppm (0.6 x 10-6 to 2.9 x 10-6 uCi/ml) in acetic acid that had been in contact with red glazed ceramic dinnerware for 24 hours. The range of concentrations went up to 41 to 51 ppm (1.4 x 10-5 to 1.7 x 10-5 uCi/ml) for 60 hours of contact.

Landa and Councell measured uranium concentrations of 3.9 to 10.6 ug/liter (1.3 x 10-9 to 3.5 x 10-9 uCi/ml) in water, 470 to 31,800 ug/liter (1.6 x 10-7 to 1.1 x 10-5 uCi/ml) in acetic acid, and 96,100 to 304,000 ug/liter (3.2 x 10-5 to 1 x 10-4 uCi/ml) in nitric acid. In each case, the solutions had been in contact with the dinnerware for 24 hours. Landa and Councell noted that repeated exposure to these solutions resulted in a reduced leaching of uranium.

Based on the above leaching rates for 24 hour contact periods, NUREG-1717 estimated that an individual using nothing but this type of dinnerware might consume 0.21 grams of uranium per year. Then, using an ingestion dose factor of 1.9 x 10-4 mrem/ug, NUREG-1717 estimated that such an individual might have an effective dose equivalent of 40 mrem per year. This was the highest dose calculated in any of the exposure pathways considered by NUREG-1717. "

http://www.orau.org/ptp/collection/consumer%20products/fiesta.htm

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#2
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Re: Geiger tube counts pseudo standard

03/28/2017 3:22 PM

Yes, fortunately, we do not have any plans to handle except with tweezers (later on we pick the nose hairs). Alternatively, we will just read the chips (may the fall where they may, and lie there), and log that as a check prior to each experimental reactor run.

I still don't understand the previously low count, unless what we are seeing is mostly gamma, does that make sense?

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#3
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Re: Geiger tube counts pseudo standard

03/28/2017 3:41 PM

I don't know what you are seeing....unless you have a different color glaze comparison....

"Count rate measurements are associated with the detection of particles, such as alpha particles and beta particles. However, for gamma ray and X-ray dose measurements a unit such as the sievert is normally used.

Both cpm and cps are the rate of detection events registered by the measuring instrument, not the rate of emission from the source of radiation. For radioactive decay measurements it must not be confused with disintegrations per unit time (dpm), which represents the rate of atomic disintegration events at the source of the radiation. [1]"...

https://en.wikipedia.org/wiki/Counts_per_minute

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#7
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Re: Geiger tube counts pseudo standard

03/28/2017 4:09 PM

I understand we are not reading the actual emission rate. Our Geiger tube display card has onboard voltage generator, pulse discriminator, a simple micro controller to derive counts per minute, total counts since power up, and calculated μSv, based on the factor for the tube being used (SBM-20 factor is about 300 +/- as I recall, maybe 380.)

Dose ~ cpm/380. (units of μSv). I understand that to get the actual source intensity, one needs to know the type of particle, the energy of the particle, the detector efficiency for that particle at that energy, the acceptance angle of the instrument at the distance from source employed, and integrate all that out to 4π steradians.

ATESI conversion chart

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#4
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Re: Geiger tube counts pseudo standard

03/28/2017 3:49 PM

Beta radiation can be reduced significantly by just a few mm of aluminium plate, but heavier metals tend to produce secondary effects. It is quite possible the beta radiation is penetrating the wrapper, striking your GM tube's metal walls resulting in seconary gamma or X (Bremsstrahlung) radiation inside the tube. What sort of all-metal GM tube does your counter use? What metal does the tube use? Steel? Does it have a beryllium end-window?

Uranium's decay-product chain includes a number of isotopes that are much 'hotter' than the uranium itself - radium for instance - and so the aggregate tends to become more radioactive as time goes on.

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#5
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Re: Geiger tube counts pseudo standard

03/28/2017 4:00 PM

The tube apparently has no window, just an oddly colored metal wall (cylindrical). Sort of yellowish hue. Not quite the color of Admiralty brass, has more silver color.

Is this an Aluminum-Beryllium alloy possibly? I do not recall. Can't imagine it would resist corrosion at all, or hold up to any abuse. The thing appears to be something not to mess with for fear of breakage.

These sell all day on E-bay.

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#6
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Re: Geiger tube counts pseudo standard

03/28/2017 4:04 PM
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#8
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Re: Geiger tube counts pseudo standard

03/28/2017 4:17 PM

Good! Yet another source. I ordered a back-up card and tube already, before my buddy got the first one up and running.

I think circa 1930 Red Fiesta chips are still fairly young, and I have had them in hand (not literally) for less than six weeks. I don't think the source changed that much in such a span.

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#9
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Re: Geiger tube counts pseudo standard

03/28/2017 4:47 PM

haha maybe the're enriching themselves....

"The uranium-containing red glaze was used from 1936 to 1943. It was discontinued from 1944 to 1958 due to a shortage of uranium caused by demand from the U.S. Government to build reactors and bombs. It was produced again from 1959 to 1969. The uranium that was used during this last period was supposedly "de-enriched" by removal of the fissionable isotope, Uranium 235. This geiger counter is reading approximately 3 mR/hr. "

http://www.dangerouslaboratories.org/rglass.html

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#10
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Re: Geiger tube counts pseudo standard

03/28/2017 4:57 PM

Yes, that stuff is just way beyond the pitcher dangerous! That is a lot of rads per year by the time one multiplies the hourly by the number of hours.

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#11
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Re: Geiger tube counts pseudo standard

03/28/2017 5:23 PM

I collect antique uranium (aka 'Vaseline') glass.

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#17
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Re: Geiger tube counts pseudo standard

03/29/2017 11:54 AM

Oh swell - my parents collected antiques and we used them daily at times. My Mother just loved the red Fiesta Ware and the green vaseline plates - yep she had quite a collection of them The juicer - yeah that too.

Andrew Westerman posted a map in another post that showed I was minimally exposed to fallout radiation in my milk and ice cream, based on geographical location (bless the Alleghenies which shielded my home from westerly winds) But now I find our dinner ware and accompanying processing ware more than made up for that. When do my teeth start to glow?

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#19
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Re: Geiger tube counts pseudo standard

03/30/2017 1:17 AM

Low level radiation might not have done any net harm... it might even have been beneficial.

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#20
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Re: Geiger tube counts pseudo standard

03/30/2017 9:20 AM

I was just joking, as this is the least of my worries. I worked 11 years for an oil field logging company using Cesium 137 sources and Plutonium 238. We had a couple of "incidents", where a number of us were exposed for extended times to well over the allowable limits. I mean, when a fellow employee gets confused between the dummy plug for the source in an instrument, and the actual source, and walks around for hours with the live source in his pocket, and you stand beside him numerous times, this tends to give you some serious radiation. Not as bad as the one who made the mistake, but still not good. Then there was the time the o-ring failed on a cesium source, and no back up source was available for most of a day. One does what one has to to get the job done and get the drilling rig off the customers site, and having a back up o-ring available, well, upper level company officials never knew about what I did as the radiation monitoring badge was removed from the vicinity - just me and my district manager knew what happened. I'm still waiting for my fingers to drop off. Wonder if that is the cause of my eyes being less than stellar these days.

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#21
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Re: Geiger tube counts pseudo standard

03/30/2017 12:40 PM

Pu-238 is an alpha emitter and the top layers of skin are sufficient to stop the alphas. Its chief danger is inhaling or ingesting it.

Cs-137 is a different story. It's a beta emitter and beta is far more penetrating.

Which plug did he have in his pocket?

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#22
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Re: Geiger tube counts pseudo standard

03/30/2017 1:35 PM

Pu-238 alloyed with beryllium emits some serious neutrons, which the body does stop, after they rip DNA to shreds. We used it to bombard rock formations with neutrons and monitor how many reduced energy (epithermal) neutrons came back as an indication of hydrocarbon concentrations. Alpha radiation wouldn't have done crap in a borehole with mud.

The guy with the source in his pocket, Pu-238, has a monthly blood check at a hospital for life. Wonder who pays for that now that the company has folded?

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#23
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Re: Geiger tube counts pseudo standard

03/30/2017 1:42 PM

Pu-238 alloyed with beryllium is a different story. You didn't mention that part. That changes things considerably. Also keep in mind that the majority of this forum's readers have no experience with oil wells and would have no idea what purpose those plugs serve apart from your saying only that they have something to do with testing. Remember, you're writing to a general, albeit largely technically-literate, audience.

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#24
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Re: Geiger tube counts pseudo standard

03/30/2017 2:34 PM

Yeah - I had forgotten that too, until I realized you were right in saying it is an alpha emitter. It has been almost 30 years now since I last used a neutron tool. I thought about it and then remembered we had an alloyed source. We never called it a Pu238/beryllium source in the field - just Pu238. So in reality, it has been 40 years since I learned what the neutron source consisted of.

Thank you for the reminder, but, that has been my story all my life and I doubt I'll change now. They introduce me to customers, here at work, as the company's Sheldon Cooper just to warn them what is coming when they talk to me.

I write descriptions in each quote of the control systems we are proposing here at work, and they get another engineer to read it and dummy it down for me. I've had questions in the exception pages of quotes rejected by my own company as too hard to interpret.

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#25
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Re: Geiger tube counts pseudo standard

03/31/2017 3:21 AM

Yeah, I've never heard anyone make claims of hormesis for neutron radiation.

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#26
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Re: Geiger tube counts pseudo standard

03/31/2017 8:09 AM

I lost track of the fellow with the neutron source in his pocket, I was moved 4 times by this company, and that was at the first base, but I bet he never had any children.

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#27
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Re: Geiger tube counts pseudo standard

03/31/2017 8:46 AM

He did.

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#31
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Re: Geiger tube counts pseudo standard

03/31/2017 9:35 AM

How epithermal are those neutrons? The way I understand neutrons, is that very cold neutrons are far more likely to be absorbed by virtually everything.

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#32
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Re: Geiger tube counts pseudo standard

03/31/2017 10:01 AM

Well, lets see, this goes back more than 30 years. The density log using gamma rays from a cesium source was about returning scattered gammas, to determine porosity, and the neutron the opposite, as absorption was what you were determining to figure hydrocarbon content, rather than scatter, and the resistivity log was, well, how resistive the fluids in the rock matrix pores was. Combined they gave a determination of porosity and water versus hydrocarbon content. There was also a gamma ray log which was placed way ahead of the density tool and it's gamma ray source. This let you determine shale / sand stone / limestone/ dolomite / coal / and so on. You know, I forget exactly how this worked, but have copies of both Birdwell and Dresser Atlas manuals on tool theory and calculation theory sitting in my garage on a shelf.

I know we had 2 different neutron logging tools. One used the source as it was and had 2 detectors at different spacing from the source, to allow compensation for absorption in the borehole, and the other was an epithermal neutron tool, which shielded the source to intentionally slow the neutrons down before the entered the borehole. The latter was used exclusively in eastern gas well areas where boreholes were drilled with very little fluid and blown dry before logging. The tool didn't work well in drilling mud. There you ran the compensated one, which means I ran it in school and almost never again. All I remember of the epithermal neutrons were they were some energy above Brownian.

Going to have to grab those manuals at lunch time to remember the theory.

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#39
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Re: Geiger tube counts pseudo standard

03/31/2017 2:28 PM

Okay, I see you mention hens teeth below.Yeah - this gets into neutron capture cross sections and such. I should mention the logs are sometimes called neutron lifetime logs, as that is what is being measured.

Very simply put, you can calculate porosity with a tool that reads scattered gamma rays, and porosity from a neutron measuring tool, as mentioned, and where the two are extremely different, well, you have lots of hydrogen. Maybe that is too simplified, but you get the idea. Now with the use of resistivity we can further determine salt water (borehole water is always salty)or hydrocarbons. Then add to that that chlorine in the salt has quite an effect on neutron capture and things get even more interesting. To present all the cross sectional charts for neutron capture and such would take a manual like I have at home, that is 8 1/2 x 11 paper and 500 pages long. Then there is a similar manual for comparing density readings from a density tool (gamma ray scattering) and neutron log porosity. It maybe a bit shorter, but not much. And finally a third with the resistivity readings added to the calculation mix.

We were very thrilled in the oil field when the tedious value versus depth reading and calculations from the three logs were finally automated. We recorded four diiferent tool logs on a tape recorder, and played them back through a processor that did the calculations for us and plotted them on a log similar to what was originally recorded, but reading porosity and % hydrocarbons beside the gamma ray log of the borehole for formation identification, instead of density, resistivity, and neutron cross section.

I have a programmable Radio Shack calculator still in my possession that was programmed to accept the three log readings and calculate the porosity and hydrocarbon saturation from when I had to manually write down the three log values at certain intervals. After logging calculations could take 4 or more hours at one time.

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#40
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Re: Geiger tube counts pseudo standard

03/31/2017 2:34 PM

Yes, it gets so complicated. Amazing we can still get to the oil, and fuel the next generation. Way to go!

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#41
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Re: Geiger tube counts pseudo standard

03/31/2017 3:18 PM

Best part of this, is they managed to cram all this into electrical, mechanical, and industrial engineers heads inside of 6 weeks, well enough to allow us to go on site and converse knowledgeably with trained geologists, and actually analyze the well. They had found they couldn't jam all this physics into a geologists head, so they turned to engineers. We can be trained to do anything.

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#42
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Re: Geiger tube counts pseudo standard

03/31/2017 3:24 PM

Trainable is the key to any employment.

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#33
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Re: Geiger tube counts pseudo standard

03/31/2017 11:09 AM

Epithermal is greater than .2ev and less than 1ev.

The idea is to have one or more collisions and slow down into thermal neutron speed, where you have more time around nuclei in the area to be absorbed by the strong force. The energy of the gammas released after the absorption tells you what isotope was created when the neutron was absorbed.

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#36
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Re: Geiger tube counts pseudo standard

03/31/2017 11:34 AM

The cold neutrons I was referring to are supposed formed by electron capture of immobilized proton on matrix, such that the Heisenberg criterion allows it to take place, and I have no idea if it requires tunneling capture. Supposedly it follows that a translationally zero degree neutron results, but is soon nudged out of place (or captured due to an abnormally high neutron absorption cross section for cold neutron by most elements). The likelihood of such a neutron making out of the reactor is essentially zero. Epithermal at 0.2-1.0 eV I suppose the cross-section has already decreased with respect to capture. Thus the new cold neutron will only have picoseconds or nanoseconds before being thermalized by atomic vibrations nearby.

This stuff is almost as difficult as finding hens teeth.

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#37
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Re: Geiger tube counts pseudo standard

03/31/2017 12:20 PM

I was curious about the mechanism for neutron formation from protons. I already knew that the basis for cold fusion is to trap the source nuclei in a lattice and let the lattice provide the pressure to bring the nuclei into close proximity. I was unclear about whether you could transform a proton to a neutron, as the energetically favored reaction is for an unattached neutron to spontaneously decay to a proton plus a beta. It is rare for protons to absorb electrons and become neutrons. Typically an unattached proton grabs an electron and becomes monatomic hydrogen, leading to embrittlement of any associated metals. I can't say neutron formation won't happen, just that it's statistically unlikely.

I would expect a better likelihood of success with deuterium as you don't have the statistical hurdle of the proton to neutron transformation to contend with.

I have also assumed that you would need to essentially supersaturate the host lattice with fusible nuclei in order to force two nuclei into the same lattice pocket in order to get the necessary proximity to overcome electrical repulsion with strong force, or weak force, whatever.

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#38
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Re: Geiger tube counts pseudo standard

03/31/2017 1:59 PM

We have also considered a so-called D-D mechanism, but the natural occurrence of D in normal rain or distilled water is pretty low. Nearest neighbor would also certainly be H.

There is something odd about D-D interaction, as there appears to be a binding energy resonance, noting how high 4He binding energy is.

If you want more about protons capturing electrons to yield neutrons consider the information on this site:

http://brillouinenergy.com/science/lenr-cecr/

I think these folks have already achieved something like a 2 CoP, but were looking for a 3 CoP (heat out = 3 x heat in). They go into a considerable amount of detail about their patented process. Our matrix and methods differ, but same general idea.

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#12

Re: Geiger Tube Counts Pseudo Standard

03/28/2017 5:28 PM

If you are using chips from Fiestaware, there may be significantly different levels measurable depending on the arrangement and strucuture/shape of the chips.

There may be a clear nonradioactive glaze over radioactive glaze. There should be a low or no radioactivity portion under the radioactive glaze that made up the bulk of the original piece.

Depending on the size, depth, and shape of the chips relative to the layer of radioactive glaze, you should get different counts from different sides of a single chip.

.

.

parent nuclidehistoric name (short)

[citation needed]

historic name (long)atomic mass

[RS 1]

decay mode

[RS 2]

branch chance

[RS 2]

half life

[RS 2]

energy released, MeV

[RS 2]

daughter nuclide

[RS 2]

Subtotal MeV

238U

U

I

Uranium I238.051

α

100 %4.468·10

9a

4.26975

234Th

4.2698

234U

U

II

Uranium II234.041

α

100 %2.455·10

5a

4.8598

230Th

11.6708

234Th

UX

1

Uranium X

1

234.044

β

100 %24.10

d

0.273088

234mPa

4.5428

234Pa

UZUranium Z234.043

β

100 %6.70

h

2.194285

234U

6.8110

234mPa

UX

2, Bv

Uranium X

2, Brevium

234.043

IT

0.16 %1.159

min

0.07392

234Pa

4.6168

234mPa

UX

2, Bv

Uranium X

2, Brevium

234.043

β

99.84 %1.159 min2.268205

234U

6.8110

230Th

IoIonium230.033

α

100 %7.54·10

4a

4.76975

226Ra

16.4406

226Ra

RaRadium226.025

α

100 %1600 a4.87062

222Rn

21.3112

222Rn

RnRadon, Radium Emanation222.018

α

100 %3.8235 d5.59031

218Po

26.9015

218Rn

218.006

α

100 %35

ms

7.26254

214Po

37.3053

218Po

RaARadium A218.009

β

0.020 %3.098 min0.259913

218At

27.1614

218Po

RaARadium A218.009

α

99.980 %3.098 min6.11468

214Pb

33.0162

218At

218.009

β

0.1 %1.5

s

2.881314

218Rn

30.0428

218At

218.009

α

99.9 %1.5 s6.874

214Bi

34.0354

214Po

RaC'Radium C'213.995

α

100 %164.3

μs

7.83346

210Pb

45.1388

214Pb

RaBRadium B214.000

β

100 %26.8 min1.019237

214Bi

34.0354

214Bi

RaCRadium C213.999

β

99.979 %19.9 min3.269857

214Po

37.3053

214Bi

RaCRadium C213.999

α

0.021 %19.9 min5.62119

210Tl

39.6566

210Tl

RaC"Radium C"209.990

β

100 %1.30 min5.48213

210Pb

45.1388

210Po

RaFRadium F209.983

α

100 %138.376 d5.40745

206Pb

51.7709

210Pb

RaDRadium D209.984

β

100 %22.20 a0.063487

210Bi

45.2022

210Pb

RaDRadium D209.984

α

1.9·10

−6 %

22.20 a3.7923

206Hg

48.9311

210Bi

RaERadium E209.984

β

100 %5.012 d1.161234

210Po

46.3635

210Bi

RaERadium E209.984

α

13.2·10

−5 %

5.012 d5.03647

206Tl

50.2387

206Tl

RaE"Radium E"205.976

β

100 %4.202 min1.532221

206Pb

51.7709

206Pb

RaGRadium G205.974stable----51.7709

206Hg

205.978

β

100 %8.32 min1.307649

206Tl

50.2387

See that 234mPa a fee lines down form the top? the one with the 99.84% likelihood? That decay yields a beta with an energy of 2.26 MeV. That is an energetic electron. Even with its charge it is going a good distance and material like plastics won't often stop it without being very thick. Shipper envelope and plastic bag may get lucky and get of these every once in a while but even then at 2.26 MeV secondary interactions will leave a lot for the Geiger counter to notice.

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#13

Re: Geiger Tube Counts Pseudo Standard

03/28/2017 5:41 PM

Due to secondary effects, for energetic electrons (beta radiation) a slab of polyethylene makes a much safer barrier than metal one. Seems counter-intuitive, but the energy of the secondary photons depends in part on how fast you decelerate those electrons. That kinetic energy has to go somewhere, and metals decelerate them very quickly, producing X- and gamma-ray photons. This is why the anodes of X-ray tubes are made of tungsten, for instance. Polyethylene brakes them slowly and so the secondary photons have much lower energies overall.

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#14
In reply to #13

Re: Geiger Tube Counts Pseudo Standard

03/28/2017 6:56 PM

Reread. Removed comment

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#15

Re: Geiger Tube Counts Pseudo Standard

03/28/2017 7:29 PM

This might help:

"Old Fiesta dinnerware was made using radioactive glazes. While the red pottery is noted for its especially high radioactivity, other colors emit radiation. Also, other pottery from the era was glazed using similar recipes, so just about any pottery from the early to mid 20th century may be radioactive. The dishes are highly collectible, both because of their vivid colors and because the radioactivity is cool.

Would you be safe eating off the dishes or would it be better to place them high on a shelf, to admire from afar? Here's a look at just how radioactive the dishes are today and the risks of using them for serving food.

WHAT'S IN FIESTA THAT IS RADIOACTIVE?

Some of the glazes used in Fiesta Ware contain uranium oxide. Although several colors of glazes contain the ingredient, the red dinnerware is best known for its radioactivity. The uranium emits alpha particles and neutrons. Although the alpha particles don't have much penetrating power, the uranium oxide could leach from the dinnerware, particularly if a dish was cracked (which also would release toxic lead) or the food was highly acidic (like spaghetti sauce).

The half-life of uranium-238 is 4.5 billion years, so you can rest assured pretty much all of the original uranium oxide remains in the dishes. Uranium decays into thorium-234, which emits beta and gamma radiation.

The thorium isotope has a half-life of 24.1 days. Continuing the decay scheme, the dishes would be expected to contain some protactinium-234, which emits beta and gamma radiation, and uranium-234, which emits alpha and gamma radiation.

JUST HOW RADIOACTIVE IS FIESTA WARE?

The workers who made the dishes seem not to have suffered any ill effects from exposure to the glazes, so you really don't have a lot to worry about, just being around the dishes.

That being said, scientists at Oak Ridge National Laboratory have measured radiation from the dishes. A standard 7" "radioactive red" plate (not its official Fiesta name) will expose you to gamma radiation if you're in the same room as the plate, beta radiation if you touch the plate, and alpha radiation if you eat acidic foods off the plate. The exact radioactivity is difficult to measure since so many factors play into your exposure, but you're looking at 3-10 mR/hr. The estimated daily human limit rate is only 2 mR/hr. In case you're wondered just how much uranium that is, researchers estimate a single red plate contains approximately 4.5 grams of uranium or 20% uranium, by weight. If you eat off the radioactive dinnerware daily, you would be looking at ingesting around 0.21 grams of uranium per year. Using a red ceramic teacup daily would give you an estimated annual radiation dose of 400 mrem to your lips and 1200 mrem to the fingers, not counting the radiation from ingesting uranium.

Basically, you're not doing yourself any favors eating off the dishes and you certainly don't want to sleep with one under your pillow. Ingestion of uranium could increase the risk of tumors or cancer, particularly in the gastrointestinal tract.

However, Fiesta and other dishes are a lot less radioactive than many other items produced during the same era.

WHICH FIESTA WARE IS RADIOACTIVE?

Fiesta commenced commercial sales of colored dinnerware in 1936. Most colored ceramics made prior to World War II, including Fiesta Ware, contained uranium oxide. In 1943, manufacturers stopped using the ingredient because the uranium was used for weapons. Homer Laughlin, the maker of Fiesta, resumed using the red glaze in the 1950s, using a depleted uranium. The use of depleted uranium oxide ceased in 1972. Fiesta Ware manufactured after this date is not radioactive. Fiesta dinnerware made from 1936-1972 may be radioactive.

You can buy modern Fiesta ceramic dishes in just about any color of the rainbow, though the modern colors won't match the old colors.

You can even get red! None of the dishes contain lead or uranium. None of the modern dishes are radioactive."

https://www.thoughtco.com/how-radioactive-is-fiesta-ware-608648

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#16

Re: Geiger Tube Counts Pseudo Standard

03/28/2017 8:13 PM

"... we initiated Geiger testing by the reactor, hoping to detect Beta or Gamma radiation from the experiment. We really only expect Beta radiation. We are sure that Alpha radiation cannot penetrate the reactor."

What sort of 'reactor' ?

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#28
In reply to #16

Re: Geiger Tube Counts Pseudo Standard

03/31/2017 9:16 AM

Electrolysis reactor. Don't go getting too excited.

It seems that my buddy, had one set up with the SMB 20 tube about 0.5 cm from the shipper bag, with nested polyethylene bag, and got some 900 cpm. Then he placed a thin aluminum electrical box lid (like the ones at Radio Shack), about 0.030" thickness.

The count was lowered to about 290 cpm. I think this is consistent with what everyone has been telling me on this thread.

I have not figured out how he got the 2500 cpm reading, but that almost has to be close contact with source materials.

Typical background of the immediate vicinity of our electrolysis setup was 10 cpm. With the experiment only just powered up within an hour of operation we were seeing 19-35 cpm, considerably more variable. I have no further data. I think he is waiting for me to show up there at the farm once again, because we only have minimal data logging systems up and running at this point after a re-arrangement.

New server power supply HP ESP120, and Chinese made PSU (don't tell Trump), are working hand-in-glove. Absolute control of whatever current we dial in up to 15 amps. Previous work in our group (over in England) got high count readings after a long induction time (about 10-20X background) which totally died off back to background rate after 20-30 minutes. This suggests (does not totally prove yet) a NAE was established in solution (or on the surface of our matrix), that was ejected from an open tub electrolysis, and this as a result of localized XSH (bump boiling behavior when bulk solution was far below normal boiling point).

Our reactor has a lid on it, and the system will let go at precisely 28 psig, sort of violently throwing off the lid as you may well imagine, but we are not running more than about 30 kPa now, based on back-pressure due to gas bubblers, etc. in line.

Our experiment has certain calorimetry monitoring, that should reveal the power in versus power out (thermal) balance, once dry gas flow is measured, and we have at least on bomb calorimeter result that estimates properly the heat content of the gas produced. We suspect the gas will have about 286 kJ/mole as hydrogen (S.T.P.)

If our findings are anything other than the usual ( unity or less than unity heat balance ) you gentlemen and ladies will be the first ones outside our research group to know it.

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#29
In reply to #28

Re: Geiger Tube Counts Pseudo Standard

03/31/2017 9:21 AM

"I have not figured out how he got the 2500 cpm reading, but that almost has to be close contact with source materials."

If it happens again, check outside the barn to see if Phys' old oil-field buddy is lurking about with that Cs-137 plug still in his pocket. You never know.

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#18

Re: Geiger Tube Counts Pseudo Standard

03/29/2017 12:31 PM

Going from counts per minute to radiation dosage doesn't directly correlate.

You are measuring counts per minute per square centimeter (flux) and dosage is energy absorption per unit volume (Rads and Rems). The number of particles generates the flux. The number of particles times energy level generates the dose.

I agree that you are most likely not seeing alpha radiation as a sheet of paper will usually stop alphas.

The tube you are using measures hard beta (electrons over 1000 electron volt energy). The hard beta does two things. If it strikes a light metal, aluminum or beryllium, they knock loose neutrons, x rays or low energy gamma radiation. Otherwise beta radiation can directly ionize the gas in the Geiger tube if they make it through the tube wall.

The gammas and x rays ionize the gasses in the tube, neon, argon and bromine which generate the counts when they reach the cathode in the Geiger tube. The neutrons usually don't interact with the Geiger tube gasses.

Measured radiation emissions depend on the geometry of the source, the energy level of the particles and the amount of material between the source and the detector.

Measured flux from a point source decreases with distance squared plus intermediate material absorption.

Measured flux from a linear source decreases with distance plus intermediate material absorption.

Measured flux from an infinite planar source does not decrease with radius, but only by absorption of intermediate material.

To calibrate your detector you need a source with a known particle emission rate, a known geometry and do geometry calculations for source shape and absorption of intermediate materials.

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#30
In reply to #18

Re: Geiger Tube Counts Pseudo Standard

03/31/2017 9:32 AM

I agree that Fiesta ware chips in a bag do not a point source make. I have considered ordering another standard source that is in a shielded container, however, we are interested really only in knowing (a) our SBM 20 is up and running true, and (b) can detect hot electrons and photons. I suspect now that both conditions are true.

I do not think alphas if they were being made or released by anything in our electrolysis bath could escape water, much less punch through a Lexan window about 3 mm thick, and much less make it through carbon steel reactor wall, although there could be possible Bremsstrahlung effect radiation.

The intended use of the SBM 20 is to log counts over possibly weeks at a time, and search for high spots in detected count rate. Statistical analysis proceeds from there, along with comparison of various temperature profiles (including infrared temperature), at or near the time when count maximizes. We really would be happy to see further evidence by "bump boiling events", cavitations, sharp pinging sounds within the boiling, abnormal sized gas bubbles, etc.

The reactor enclosure (for calorimetry purposes) consists of foil-back Styrofoam panels up to 2" thick (sandwiched for extra insulation), so maybe this weekend, we will install a new bore-scope (for Android or laptop) for visual inspection of reactor behavior during calorimetry.

I would suspect we need not really think we have over unity even when the heat balance goes higher than one, since nuclear transformations are not out of the question. We are not applying any unusual waveform at this time, just DC.

Later on, we will want the ability to switch on heat gain (and have a higher heat gain value) at will, and will most likely utilize a proprietary second applied waveform, designed to increase electrode efficiency, but mainly to enhance the electric flux induced motion of charged particles suspended in the bath.

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#34
In reply to #30

Re: Geiger Tube Counts Pseudo Standard

03/31/2017 11:10 AM

Are you fueling with Deuterium? If so, you could put a high point tap in the gas headspace and look for helium light spectrum. The only source for helium would be fusing of deuterium. You probably already know that an alpha particle is a helium atom ionized to the +2 state.

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#35
In reply to #34

Re: Geiger Tube Counts Pseudo Standard

03/31/2017 11:26 AM

I understand that, and agree. It has been attempted at China Lake, with some success. They had to watch the ambient Helium inventory very closely, and attempt careful purges to get the residual Helium low enough that the samples could be meaningful when read later on Mass spectrum. The result (in their deuterated experiment according to the Fleischmann-Pons protocol) was that the helium observed could only have come from nuclear transformations. Excess heat was detected 17 out of 23 times (as best as I recall) at the China Lake Lab.

Fleischmann-Pons experiment

Unfortunately, the earlier tests by MIT and CIT (and Texas A&M) largely failed to carry Deuterium loading into the Palladium to the required atom fraction.

I believe it requires some pressure slightly above ambient to reach those levels.

Our present experiment is with normal light water, a matrix of our choosing, and sodium bicarbonate electrolyte. Various electrodes may be employed, but I will not list them here. They are really nothing exotic, or specially treated. The matrix has to be prepared using another AC electrolysis procedure with a considerably higher voltage, and less electrolyte, as I recall. I have to obtain the matrix from the group leader.

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