BICKEL Gamma Ray Scintillometer

[zidex666]

More Bickel unit photos

More photos:

[zidex666]

General observations of the Bickel Unit panel controls

Looking at the front panel controls the following is observed:

The two smaller meters are over kill. One on the left center indicates the unit's current draw and the small one on the right merely indicates volts or battery condition. Those measurements could easily be combined in one meter. Great visual effect though with an unnecessary surplus of meters.

Knobs, switches etc. are standard Radio Shack items.

Cheesy off center mounted housing of the fuse holder.

The "subnormal" meter is likely utilized to indicate background noise and may be utilized to indicate what affect that the pulse shaping circuits can be utilized to attenuate it.

The "abnormal" meter is likely to read the amplitude and intensity of the gamma radiation.

In fact both of these functions (subnormal and abnormal) can be combined in one large meter. It does however add to its visual appeal for some.

The gothic lettering may be cheesy to some but as Dr. Bickel was a Nazi Rocket Scientist the choice of the gothic press-on lettering on the meter and panel faces makes sense. Depending on the client's choice we may either change the lettering or leave it as is to preserve the unit's originality.

[Bill512]

In response to Bill512:

Yes there are some scintillator probes that can be connected to certain vintage counting units made by such firms as Ludlum, Bicron, Eberline, Eltronics, etc.. and those unit are calibrated in CPM. However most vintage standalone Scintillators are calibrated in the now obsolete MR/HR. There is no standard way to convert CPM to MR/HR conveniently or accurately. It's essentially comparing apples to oranges. Hence new measuring standards are gradually being phased in. The point was that normally the output of a scintillator probe basically measures gamma flux intensity and does not rely on simple counting circuits as in Geiger Counters. so the original posting stands.

I've got my answer regarding the Bickel instrument (Disc or intensity).
However is true that the output of a scintillation tube is pulsed voltage directly related to the initial product of the NaI(T) photons? (photoelectric superimposed in compton).

This is only true in an conceptual idealized isotropic environment. Without going into the subtleties of Shannon's communications theory and simply utilizing practicle real world effects, signal to noise ratios are NOT fixed but independently variable. Either the source may be amplitude varying or the Background noise maybe be amplitude and time varying. In either or both cases the signal to noise ration is affected. If the background noise is of greater amplitude than the source signal, the source is swamped out by the background noise. The result is that the signal to noise ratio changes.

was necessary to mention the (trivial) note, that the source's are constant in time in this case? my intention was to be a simple example.
Now, lets see the more realistic cases.
Any time variance of the sources flux, has effect on the noise to signal ratio but this has nothing to do with any detector.
Let the ratio be variable all the time, with whatever function you like.
The point is that the "ultimate" (barrier) signal to noise ratio is a property of the space it's self, and not instrumentation related.
As you make an instrument more and more sensitive there is a point beyond that any improvement in terms of sensitivity is useless.
This is not because the signal then is buried in noise as in your statement: "..As you increase the sensitivity of a scintillator you increase the level of background radiation proportionately and any signal or signature of interest gets buried in the noise.."
This is simply because, beyond this point you amplify the signal as well the noise - so, no real benefit except signal scaling.

Not false!

sorry, but these "millions of miles of lead shield" was to shield the gamma radiation of a cosmic event in the order of magnitude of the bing bang?


anyway,many thanks for the Bickel info and the nice talking.
this instrument was mysterious, not to say (almost) mythical...
Bill

[Geo]

After your discussion I feel to be more irrelevant but thanks again

[zidex666]

To Bill512:

See: https://en.wikipedia.org/wiki/Signal-to-noise_ratio

Regards

[zidex666]

Vintage units similar to the Bickel Detector

For comparison here are some Photos of a Vintage scintillator (gamma ray detector) unit similar in function and sensitivity the BICKEL unit. The PRI-118 was manufactured and sold during the mid to late 1950's. It utilized sub-miniature vacuum tubes developed during WW2. The appear from time to time on EBAY.

Regards

[zidex666]

Photo of a bad NaI(t) scintillator crystal

Notice the canister below with the yellow crystal. The rubber O ring seal has leaked allowing moisture into the crystal housing. Crystal units constructed in the 1950 had this problem. They typically lasted only 2 to 3 years. Once yellowed they become useless unless the crystal is removed and replaced in a moisture free environment. Sometimes they can be re-polished. In the 1960' on, manfacturers started to hermetically seal them so that they would last longer.

As mentioned in previous posts by me, NaI(t) is extremely toxic and hygroscopic. It corrodes quickly when exposed to any moisture in the air . Ggreat care and precautions most be made when replacing or re-polishing it once it has yellowed. Once yellowed and no longer transparent, the crystals are useless.

The crystal along with the photomultiplier are the heart of any scintillator unit. The rest are simply electronics that process the output from the photomultiplier tube.

In addition to Nai(t) other materials such as special plastics and other compounds are used for monitoring certain bandwidths of the X-ray/Gamma spectrum are used today.

The myth that only the most sensitive scintillation crystal and/or photomultiplier tubes are only available from Germany is inaccurate and false. Both are now manufactured worldwide by many firms including some in Russia and China.

Regards

[Geo]

Hello.
Today on ebay we can find scintillation crystals and photomultiplier tubes easy and at low prices. How difficult or easy is to construct a new device like Dr Brickel's ? For example Dr brickel was using a lot of components to make a digital counter and now it is fixed (i mean all components and display at same small case) at very low price. Except the protectiob for good shielding are there other things who makes the construction unposible or unworkable?

Regards

[zidex666]

Hello.
Today on ebay we can find scintillation crystals and photomultiplier tubes easy and at low prices. How difficult or easy is to construct a new device like Dr Brickel's ? For example Dr brickel was using a lot of components to make a digital counter and now it is fixed (i mean all components and display at same small case) at very low price. Except the protectiob for good shielding are there other things who makes the construction unposible or unworkable?

Regards

Hi Geo,

Yes there are on Ebay. Some really good ones are available from some Russian sellers. I suggest that you get a 6619 photomultiplier tube to mate with a 1 inch diameter NaI(t) crystal as a first project. Another idea is to get a vintage PRI-111 or PRI-111b scintillator or an alternative unit off EBAY and restore it.

Making Bickel's digital counter is unnecessary simply because you can buy panel mounted digital counter modules on EBAY for less than $20 USD. It works kind of like a simple kitchen digital count-down timer. All that counter does is to count "seconds" backwards to shut off an external electromechanical paper chart unit than can be connected to the Bickel unit.

There is simply NO way that the Bickel Counter, no matter what its count display, can accurately identify an individual isotope unless a scalar reading with an external chart recorder is utilized. Even then it's only a guess at best. It merely counts time in Seconds not isotope number. Furthermore, it is extremely improbable that the Bickel unit can identifiy any gold isotope by reading some mysterious number on the counter display. Gold in nature is stable and any gold isotope that is radioactive can only be so if it is "synthetic." That means that it must be strongly irradiated with radioactivity and in essentially laboratory conditions. Additionally any such synthetic radioactive gold isotopes have comparatively short half-lives.

The only things that the Bickel unit along with other NaI(t) based scintillometers detect and are most useful for are
radioactive sources emitting gamma/xray radiation in the field. Primarily decay products from Thorium and Uranium as they eventually decay into lead. Do a search on Uranium and Thorium decay products (example radium. etc.) to learn how Uranium or Thorium eventually transmute into Lead. Also, look up the half-life of the individual elements as they decay into lighter elements in the decay chain.

Finally, there is NO magic or obscure Nazi Science manifest in the Bickel unit. It's a rather conventional Scintillator design with an unnecessary bunch of extra bells and whistles, fancy knobs and unnecessary meters. In order to identify ore fields that were found using the Bickel unit, other extant scintillator at the time could have given equivalent if not superior performance. Without a good knowledge of the geology of the terrain, the out-croppings, and other envronmental factors, which the Bickel may certainly have had, a scintillator will not directly identify oil, gold, dinosaur bones, precious metals, or treasures. The exception maybe if someone buried a nuclear warhead or radioactive uranium mine tailings.

Any NaI(t) based scintillator on the other hand CAN detect long range radioactive (trans-uranium and trans-thorium) ore bodies beneath the surface. Identifying the ore body and its constituents, one can properly identify any other elements such as gold, oil, or other things requires an intimate knowledge of geology, chemical testing, borehole sampling, and other factors in addition to a scintillator.

See below some pictures of common vintage scintilltors we've restored.

FYI: The are some excellent YAHOO interest Groups that are devoted to Geiger Counters and Scintillators.

Regards

[Geo]

Zidex thank you.
Do you think that one device like these can catch buried gold 100 years at depth 4m and weight 500kgr??

Regards

[Nicolas]

Thanks all friends. you can contact her soon here about more information or inquiries.

http://www.longrangelocators.com/forums/showpost.php?p=73412&postcount=26

[abdou2014]

Thank You

[Mike(Mont)]

You might try to contact a member here SEDEN. I think he has studied Bickel.

[Nicolas]

Hi all
Maybe this can help you to build your neutron detectors for long range.

I advice to read it first please to understand good

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

Second you can try here to find the scheme details.

https://www.google.com/search?q=Neut...0ezDnSkmSSM%3A

Third you can build your neutron detectors here.

http://uzzors2k.4hv.org/index.php?page=rs232geiger_counter

or this

http://www.blackcatsystems.com/GM/geiger_counter.html

or this

http://www.imagesco.com/articles/geiger/build_your_own_geiger_counter_-_gm_tube.html

http://www.berkeleynucleonics.com/wordpress/?m=200910

http://www.berkeleynucleonics.com/products/model_940.html

http://www.directindustry.com/prod/canberra-industries/product-23661-1346769.html

For us we use the thermal detection and we are competent in this domain

https://www.youtube.com/watch?v=oVAlQhLRB1I

https://www.youtube.com/watch?v=uRkqy4K7o9g

https://www.youtube.com/watch?v=Rokwo50EoL0

Good luck to all

Best regards
Nicolas

[Nicolas]

https://www.orau.org/ptp/collection/surveymeters/surveymeters.htm

https://www.orau.org/ptp/collection/surveymeters/precisionroyal.htm