Posts Tagged ‘radioactive’


Nuclear Collection (Part II)

March 1, 2009

Here are some more photos of my radioactive material collection. Featured today are radioactive vacuum tubes, radioactive optics, radioluminous items containing radium, and some recently-acquired resistors containing uranium.  I collect and buy radioactive material (duh!).  If you have some, and it’s in need of a good home, let me know!

radcollection_tubesMany types of electronic tubes contain radioactive material. Click on the thumbnail for a larger, numbered image. The purpose of adding a radioisotope to a vacuum tube is usually to ionize residual gas in gas-filled types, improving the timing characteristics or helping to “strike” a discharge.  Uranium glass saw much use in the metal-to-glass seals for tubes of all kinds.  Its coefficient of expansion more closely matches the metal than the regular soda glass of the package, and the slight radioactivity is merely incidental.  Various isotopes are found in tubes: these can include artificial H-3, Ni-63, Kr-85, Co-60, and Cs-137; and natural Ra-226 and Th-232.  The activity is usually internal to the tube, but some of the examples shown here feature external radium sources.

radcollection_lensesSome lenses contain thoria (ThO2) to improve the refractive index while keeping dispersion low.  The thorium content can range from barely-detectable to major constituent of the glass.  Along the back row, left to right:

  • Unknown first-generation image-intensifier tube from a military night-vision system.  The output optic on this tube is, as far as optics go, the most radioactive thing I have encountered–it reads 50 kcpm on a pancake GM tube, and about 1.5 mR / hr on an ion chamber.
  • Kodak Pony 135 Model C camera (mid-1950s), with thoriated Anaston lens.  Not all Ponies have radioactive lenses.  Reads 4500 cpm on a pancake GM tube.
  • Angenieux zoom lens for television or film, Type 10 x 15 B.  Reads 350 cpm on a pancake GM tube (the radioactive lens itself is buried deep within the assembly).
  • In front are some small lenses salvaged from a variety of ’50s-’60s-vintage still and movie cameras.  Hottest among these is a Kodak 3″ f/2.8 Ektar lens, reading 10 kcpm on a pancake GM tube.

radcollection_radiumRadium paint was used for glow-in-the-dark applications from the 1910s through the ’60s.  Many people know of the tragedies suffered by early watch dial painters due to ingestion of radium.  The articles in my collection were probably all machine-painted, however.  The glow from these devices is feeble today, the result of radiation “burnout” of the zinc sulfide phosphor and NOT because the radium has decayed.  It remains virtually as radioactive as it ever was.

  • In the back are WW-II / Korean War vintage military aircraft instruments: gyrocompasses, a radio compass, fuel gauges, an “oxygen flow indicator” and a small pressure gauge.  The latter item was sold in large quantities in 2002-2003 by various surplus dealers.   The larger dials probably contain a few microcuries of Ra-226.
  • Lower left: radium-tipped toggle switches.  Radium content is probably a few tenths of a microcurie.
  • Right: some consumer timepieces with radium–Westclox “Pocket Ben” watch and a Phinney-Walker travel alarm clock.  The older Westclox “Big Ben” clocks are also reliably radioactive and still inexpensive and commonplace collectibles.
  • Center: two instrument knobs with external radium paint: “Pull out before preset tuning” and an illuminated on/off knob
  • Center right: 10 ampere circuit breaker with radium strip that is visible when breaker is open
  • Center foreground: two radium drawer pulls (or glowing eyes for a radioactive teddy-bear?)

radcollection_resistorsRadioactive power resistors obtained at “The Black Hole” in Los Alamos.  The activity appears to be due to uranium and its daughters as determined by gamma spectroscopy.  At first I thought the uranium was in the black vitreous glaze, but it actually appears to be distributed throughout the volume of the resistor material (also black in color).  The activity is relatively mild–only about 300 CPM above background on a pancake GM detector.


Nuclear Collection (Part I)

May 5, 2008

Here are some relatively recent additions to my collection of radioactive and nuclear-related items. Some of them I don’t know nearly enough about! Take a look, and if you have some information to add, please contact me. I will post other galleries as I get the chance. Also: I collect this kind of stuff (obviously), so if you have something radioactive and you’re not a big fan of radioactive stuff, let’s make a deal: send it to me. You get rid of the hot stuff that’s gonna harelip your kids and give you leukemia and whatnot, and I’ll pay you money for it.

Click on a photo for large size. Descriptions are at bottom of post.

graphite from CP1Graphite from CP-1, the world’s first nuclear reactor, built under the stands of Stagg Field at the University of Chicago in 1942. This 25th Anniversary memento popped up on eBay not long ago and I paid dearly for it. However, there’s not much of this stuff left; all but a couple bars of this famously pure graphite went on to be incorporated in CP-2 and thereafter entombed in concrete under a nondescript field in Illinois. The eBay seller would only say “I do know that my grandfather worked on the building of the atomic bomb but other than that I don’t know much else.” I have a feeling that the human story could be interesting, but on account of the seller’s reluctance to share so much as her grandfather’s name and other “personal information,” there’s nothing more to say right now. Tips appreciated…

graphite from CP1More Graphite from CP-1. This example was also obtained on eBay, but bears slightly different markings (the additional Argonne National Laboratory label on the side of the graphite piece) and different dimensions. Also, no notecard or box came with this one.

worker\'s badge from ChernobylWorker’s badge from the Chernobyl Nuclear Power Plant, dating from 1987 (the year after the catastrophe at Unit 4). Anyone able to read Russian shorthand? The back of the badge contains addresses and perhaps a description of what this man did at the plant. This badge is not discernibly radioactive.

Uranium glassUranium glass memento from the “Conference Nucleaire Europeenne” of 1975, held in Paris. The box also came with a slip of paper informing the recipient that “Ce verre est colore par un sel d’uranium” (“This glass is colored by a salt of uranium”). A present from a good friend, James Thiel. Shown at right under light from a mercury vapor discharge.

ionium“Ionium thorium nitrate” from Marie Curie’s lab. At least that’s the provenance claimed by the previous curator of this fascinating and rather radioactive vial. Ionium was a name for Th-230, the naturally-occurring parent of radium (Ra-226). Today, the vial contains 8.6 +/- 10% microcuries of radium as determined by careful gamma radiation measurements. If it’s indeed as old as the Curie lab, then there should be a couple hundred microcuries of alpha-emitting Th-230 present, in addition to a rather inconsequential activity of Th-232 carrier. The vial is contained in a test tube that has some rather cryptic markings on it. Take a look at the full-size pic and let me know if this means anything to you…

Walkie recordallThis late-model Walkie-Recordall contains a 4.8 microcurie radium source. An expensive dictation recorder in its day (ca. 1950s and ’60s), the battery-operated apparatus came in a discreet suitcase with hidden microphone—perfect for industrial espionage. Radium was used to discharge static on the “sonoband” embossing medium. This specimen was found by scintillation detector in a flea market in Ohio. The included sonoband, containing a medical lecture, was heavily damaged by radiation in the place where it sat in front of the radium source for years. The band still plays (video coming shortly). I pay $50 per Walkie radium source; taking out this radioactive strip does not impact operability of the recorder.

back in the good ol\' daysBack in the good ol’ days of 2004, an average joe could still buy uranium oxide from MV Laboratories in New Jersey, with nary a question asked. Those days are history! This 30-gram quantity of greenish-black U3O8 remains sealed in its bottle, an emblem of American freedom that has been eroded by the drumbeat of irrational fear. Something about “islamofascists” I think.

alpha sourceThis is an interesting alpha check source kindly given to me by Taylor Wilson. On the backside is a bare surface deposit of black UO2, evidently reading 700 CPM on the Nuclear Chicago Model R6 survey meter. Perhaps the UO2 was electrodeposited?


radium calibration sourceAnother interesting check source from Taylor, this one an “ionotron” type radium foil (probably about 0.1 microcurie) on a card that was last calibrated in 1955 at the height of the golden age of nuclear. It’s hard to see on the photo, but radiation damage has denatured and cracked the plastic right over the source strip in the lower right-hand corner.

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