Peace through practical, proved civil defence for credible war deterrence
  • Please see also post linked here, and our summary of the key points in Herman Kahn's much-abused call for credible deterrence, On Thermonuclear War, linked here.

  • Hiroshima's air raid shelters were unoccupied because Japanese Army officers were having breakfast when B29s were detected far away, says Yoshie Oka, the operator of the Hiroshima air raid sirens on 6 August 1945...

  • In 1,881 burns cases in Hiroshima, only 17 (or 0.9 percent) were due to ignited clothing and 15 (or 0.7%) were due to the firestorm flames...

  • Dr Harold L. Brode’s new book, Nuclear Weapons in ...

  • 800 war migrants drowned on 22 April by EU policy:...

  • Photographed fireball shielding by cloud cover in ...

  • Nuclear weapons effects "firestorm" and "nuclear w...

  • Proved 97.5% survival in completely demolished houses ...

    "There has never been a war yet which, if the facts had been put calmly before the ordinary folk, could not have been prevented." - British Foreign Secretary Ernest Bevin, House of Commons Debate on Foreign Affairs, Hansard, 23 November 1945, column 786 (unfortunately secret Cabinet committees called "democracy" for propaganda purposes have not been quite so successful in preventing war). Protection is needed against collateral civilian damage and contamination in conventional, chemical and nuclear attack, with credible low yield clean nuclear deterrence against conventional warfare which, in reality (not science fiction) costs far more lives. Anti scientific media, who promulgate and exploit terrorism for profit, censor (1) vital, effective civil defense knowledge and (2) effective, safe, low yield air burst clean weapons like the Mk54 and W79 which deter conventional warfare and escalation, allowing arms negotiations from a position of strength. This helped end the Cold War in the 1980s. Opposing civil defense and nuclear weapons that really deter conventional war, is complacent and dangerous.

    War and coercion dangers have not stemmed from those who openly attack mainstream mistakes, but from those who camouflage themselves as freedom fighters to ban such free criticism itself, by making the key facts seem taboo, without even a proper debate, let alone financing research into unfashionable alternatives. Research and education in non-mainstream alternatives is needed before an unprejudiced debate, to establish all the basic facts for a real debate. “Wisdom itself cannot flourish, nor even truth be determined, without the give and take of debate and criticism.” – Robert Oppenheimer (quotation from the H-bomb TV debate hosted by Eleanor Roosevelt, 12 February 1950).

    “Apologies for freedom? I can’t handle this! ... Deal from strength or get crushed every time ... Freedom demands liberty everywhere. I’m thinking, you see, it’s not so easy. But we have to stand up tall and answer freedom’s call!” – Freedom Kids

  • Friday, March 03, 2017

    Everybody has the ability to detect and measure fallout radiation now: smartphone cameras measure radiation

    My blogger profile photo shows me measuring insignificant (compared to the natural 0.01 mR/hour or 0.1 microSievert/hour) Chernobyl fallout radiation in 1986. Nowadays, everyone can use the radioactivity sensitivity of the CCD camera chip in their smartphone to measure radiation. Just tape some lightproof black paper over the camera aperture (to keep ordinary light out) and that converts the smartphone camera into a gamma radiation meter (there is also software to calibrate it into an accurate gamma dose rate meter, as proved in the youtube video linked here):

    That's fine for high levels of gamma from fallout in a nuclear attack, you say, but what about alpha radiation, either from fallout containing inhalation dangers due to Pu239 made from neutron capture in U238 in a nuclear explosion (which produces U239, decaying with a 23.5 minutes half life into Np239, which then decays with a 56 hours half life into Pu239), or in peacetime from Mr Putin's next attempt to assassinate someone using the alpha emitter Po210?  Surely you need some expensive scintillation counter like the PCM5/1 with DP2R probe to reliably distinguish between alpha and beta/gamma, which I demonstrated on youtube?


    Above: on 3 October 1960, James Robert Brown and Jack Sharpe filed US patent 3,126,482 for EMI Limited (the music publishers who also made and sold electronics, including Nuclear Enterprises Ltd, the Edinburgh based factory for radiation meters), “Radio-activity contamination monitor with discrimination means for alpha and beta radiation,” which was granted 24 March 1964. The brains of this invention is the ability to discriminate between 5 MeV alpha particles from typical fissile and fissionable fuel (uranium, plutonium, Am-241, etc.) and 0.5 MeV typical fission product beta particles.  Alpha particles carry more energy and thereby cause larger flashes of light when they hit zinc sulphide, than beta particles (or Compton electrons released from atoms by gamma rays).  All light flashes are detected in a photomultiplier probe fed with 850 volts (which is broken down into a range of potentials by a dynode chain of resistors, allowing electrons to be accelerated by successive multiplier plates in the probe).  The box of tricks with the meter, batteries and loudspeaker contains 30 transistors (no ICs) which include two discriminator circuits for the amplified current pulses from the probe.  Large current pulses, corresponding to particles of over 3 MeV, go into an alpha particle circuit and are assigned a "beeping pulse sound", while all smaller current pulses are assigned "clicks" (like an old fashioned geiger counter).  Switched to alpha+beta, this instrument therefore allows the user to discriminate between alpha and beta radiation by the sense of hearing.  Basically, the alpha detection circuit is like the "squelch" control in an old analogue radio transceiver: it cuts out (silences) all weak "noise" and is only triggered by strong signals.  The scintillation probe is constantly sending out pulses of varying current.  The alpha discriminator circuit simply ignores all pulses which are too small to be a beta particle.  This makes the "alpha only" setting very useful in making the probe respond only to nearby contamination the clothing it is passing over.  Older geiger probe based "contamination meters" proved useless in fallout areas because of the very high background count rate from beta and gamma emitters far away from the object the probe is placed near.  These instruments were used in the British nuclear reactor industry to tell apart plutonium (alpha) from fission products (beta).  The original 1960s instrument was the bulky box-like cream plastic PCM1 and PCM2 requiring eight D cells for power and demonstrated by Sean Connery in Dr No, but a more compact green coloured metal PCM3 soon followed, which during the 1970s evolved into the 1980s cream coloured PCM5 shown into the video which requires only two D cells (or rather, two rechargable AA cells placed in plastic A cell to D cell converters).  After using the PCM5 for a few hours, you can clip the meter box by the handle into your belt and reliably assess contamination levels by hearing alone, with the probe in one hand.  Various digital display versions are now available, including the LB 124 SCINT which combines the probe and analyser into one convenient handheld unit.

    Here's good news.  Now you can measure alpha too with the camera of a good smartphone, if you put a thin layer of zinc sulphide (ZnS, sold on ebay by chemical suppliers) on the back of a sheet of transparent plastic (such as the clear "windows" in retail packaging) and then cover the zinc sulphide with a layer of thin light-proof mylar foil (such as is used in toy balloons) which will let about half of the incoming 5 MeV alpha particles through, but stops light.  Since only a small amount of zinc sulphide is needed to detect alpha particles (obviously you need a thickness of zinc sulphide that is no greater than the small range of an alpha particle in it), anyone buying a jar of it could make these hundreds or thousands of these zinc sulphide coated foil camera lens covers as very cheap "stickers", for distribution at low cost on ebay in an alpha radiation emergency: they are easily calibrated by everyone because suitable alpha radiation sources are available in household Am-241 based ionization smoke detectors (which cost about £5 in supermarkets).  Putting that ZnS sticker over the smartphone camera aperture allows alpha radiation to be measured: to calibrate it, you simply compare the reading given by a sample to that given by a 1 microcurie Am-241 alpha source, contained in all ionization smoke detectors (not optical or IR smoke detectors).  This is quite accurate, because of the tolerance of the Am-241 sources in the smoke detectors, which must conform to regulated and standardised safety standards.


    Turn the camera CCD chip in an old android based Samsung Mini smartphone into a reliable fallout radiation meter!


    Flashes occurring on the CCD image chip of the camera in a smartphone, like white dots of interference, are due to radiation.  By calibrating a smartphone with a light-covered (black taped) camera lens using the Am-241 radioactive source from an ordinary spare household smoke detector, reliable measurements of radiation are possible using everyday household items. 
    Above: scintillation counters use complex electron accelerator and multiplier vacuum tubes, but their role is simply to detect the flashes of light emitted by crystals which are disturbed by radiation.  (Note that there are no heaters, and there is a "dynode chain" of resistors to break up an input of 850 volts or whatever into a range of different potentials in the probe for different plates.  Therefore, the scintillation counter can be connected to the detector circuit box by just two conductors, e.g. simple coax cable.)  Many materials emit light in this way.  Even before the discovery in 1906 that gamma radiation from radium sources damages fast-dividing cancer cells, it has been discovered by Becquerel that ionizing radiation is like Roentgen's x-rays in having light-like properties on photographic plates (hence medical x-rays) and also makes zinc sulphide crystals glow.  While zinc sulphide responds to alpha particles, ordinary perspex (a transparent plastic) is a good beta particle phosphor.  By coating zinc sulphide on to perspex (or anthracene) you therefore get the phosphor which is the basis for the DP2 alpha-beta "dual probe".  The alpha side of the perspex is placed in direct contact with a thin light-proof mylar foil (metal coated plastic) which lets through over 50% of 5 MeV alpha particles, but stops light from entering.  Beta particles can easily penetrate the thin zinc sulphide before causing light scintillations in the perspex.  Gamma rays also produce Compton electrons with typically about half the energy of the original gamma ray, so those Compton electrons are similar to beta particles and can be detected in the same way.  A large crystal of thallium doped sodium iodide gives much greater sensitivity for gamma radiation, however. The first scintillation counter was simply zinc sulphide fixed to the inside of a thin opaque metal foil at one end of a tube, allowing a glow of light to be seen when an alpha radiation emitter is placed beside the thin light-proof metal foil: you can see the glow by looking into the open end of the tube in a darkened room and with a lens you can even see the individual flashes, just like an expensive instrument.  Geiger and Marsden used this manual approach to "counting" to prove Rutherford's nuclear atom theory by measuring the distribution of alpha particles scattered by a thin gold foil, until eye strain and boredom motivated Geiger to develop his electronic counter.

    Nuclear Enterprises (EMI) Portable Contamination Meter 5, PCM5, with scintillation probe in current use for decontamination of nuclear waste.

    EMI/Nuclear Enterprises radiation meters including two PCM1 alpha-beta discriminating meters, in the decontamination centre of the surprisingly hygienic but wicked Dr No, in the 1962 first James Bond movie.
    Sean Connery using PCM1 in the 007 film Dr No, 1962.


    Connery as 007 being carefully "frisked" by a DP2R dual alpha-beta probe, which is plugged into hand-slots and clothing monitor on the right, which has simultaneous dials for alpha and for beta contamination.  This equipment was all bona fide EMI/Nuclear Enterprises stock, and the success of the realistic decontamination sequences of the film proved a marketing help for their sales of advanced radiation monitors. Although the PCM1 was fully transistorised and used only 1.5 volt D cells (twelve of them, providing 18 volts!), it was chunky and heavy.  The PCM2 in 1965 differed only in offering a probe-clip to allow for one-handed operation.  In 1968, the PCM3 was a streamlined metal cased version of half the weight, powered by a 9 volt battery.  By 1980, this evolved into the lightweight PCM5, requiring only 3 volts (two D cells).
    Hope this blog post cheers up all those who find the current political anti-nuclear bigotry news too depressing.

    Links to app download for the Rolf Deiter Klein smartphone gamma dose rate measurement:

    https://play.google.com/store/apps/details?id=com.rdklein.radioactivity

    Note that in an emergency where this app (or another type of radiation meter) is not available, a smartphone can be used as a basic indicator of strong radioactive contamination without such an app simply by blanking off the camera lens (to make it lightproof) with black tape or a taped over piece of foil or black paper, and opening the camera app to observe the rate of small white flashes (like old fashioned analogue TV interference) on the black screen background.  Rolf Deiter Klein gives data tables here which convert the number of flashes per minute for different types of phones in to radiation levelshttp://www.rdklein.de/html/radioa_data.html.  For example, my old Samsung Galaxy Mini GT-S5570 has a calibration conversion factor of 27 flashes per minute for each microGray per hour of gamma radiation:

    Different smartphone cameras have differing sensitivity to radiation: the Samsung Galaxy S4 gave 2 flashes per minute for 1 microGray/hour while the Samsung Galaxy Mini GT-S5570 have 27 flashes/minute for the same radiation level.  In general, the newer and higher quality the smartphone camera, the more sensitive it is to radiation. (If you have a phone that has two cameras (front and back), you only need to cover up one of the cameras with tape to use as a radiation meter, leaving the other camera free to take pictures or video.  The full list of data is found at: http://www.rdklein.de/html/radioa_data.html.)


    (For those unfamiliar with radiation units, 1 milliGray = 1000 microGray = 0.001 Joule/kg = 0.1 rad which for low LET gamma radiation with RBE =1 is equal to 0.1 rem or 1 milliSievert.  For RBE =1, Grays and Sieverts are identical.  For short term exposure over a few days or less, 10 Sieverts is the lethal dose, but spread out over 25 years in the bones of radium dial painters this dose was just the threshold dose needed to cause bone cancer, because of the repair by protein P53 to damaged DNA at low dose rates which is not possible at very high dose rates.)

    His downloadable app simply counts the flashes and gives the conversion automatically.  This is useful for very high radiation levels, but even then, without the app you can still get an idea of the relative strength of the radiation by the rate at which white flashes appear on the camera when the lens is properly covered.  For example, if you take shelter in a concrete building, this will give an idea of the relative degree of fallout protection.  It will make radiation visible, and provides a great civil defence use for old "network locked" smartphones (even without a SIM card, the WiFi network access allows radiation meter apps to be downloaded, installed and properly checked).  This information about the use of smartphone cameras as nuclear radiation indicators should be included in modern civil defence handbooks.  Being able to get an indication of harmful radiation using an everyday device like a smartphone should be useful information in a radiation emergency affecting a large area and thousands of people.

    1 Comments:

    At 5:14 pm, Anonymous Anonymous said...

    I'll have to try this - I tried this once several years ago just to see if I could tell the difference between flying and not flying but it didn't work. After Fukushima, I also tried making a radiation meter out of a test PCB I did that had a photodetector circuit that I covered up. It sort of worked for gamma rays but I was hoping I could distinguish between the different gamma particle energies but they all kind of mushed together and I couldn't figure out how to control the different flux with orientation. I would have considered it a success to have detected a Cs134 decay (unique to Fukushima) but I just couldn't get it to work well enough. Back then I didn't try very hard because I have a day job that keeps me busy.

    I'm in the US and believe that we are underprepared as civilians for the North Korean threat and the time is running out to build cost-effective dual-purposed fallout&blast structures in the US in time to meet the North Korean threat. Buildings over here are well-constructed given the construction economics unique to the US and risks of earthquakes; but in a nuclear blast overpressure/fire scenario, they are very difficult to shore up compared to much of Europe.

    As some feedback, I love your site as it is a wealth of unique and thorough content and opinion. But it is very difficult to navigate because of the lengthy preamble with each page and postamble with the links and archives at the end. Is there any chance you could put the preamble and postamble in a sidebar so that I don't have to scroll through the page to find the newer articles you have written?

     

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