Hackaday Links: November 5, 2023

November 5, 2023 by Dan Maloney 5 Comments

As I write this, Supercon 2023 is in full swing down in Pasadena — 80 degrees and sunny at the moment, as opposed to 50 and pouring rain where I am, not that I’m bitter. Luckily, though, we can all follow along with the proceedings thanks to the livestreams on the Hackaday channel, which of course will all be available once they’re edited in case you miss anything live. There are a ton of interesting talks coming up, so there’ll be a lot to catch up on when the dust settles. And that won’t be far from now; by the time this post publishes, Supercon will be all but over, which makes it the Thanksgiving dinner of cons — all that work and it’s over in just a few minutes.

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DIY Repair Brings An X-Ray Microscope Back Into Focus

September 22, 2023 by Dan Maloney 6 Comments

Aside from idle curiosity, very few of us need to see inside chips and components to diagnose a circuit. But reverse engineering is another story; being able to see what lies beneath the inscrutable epoxy blobs that protect the silicon within is a vital capability, one that might justify the expense involved in procuring an X-ray imager. But what’s to be done when such an exotic and expensive — not to mention potentially deadly — machine breaks down? Obviously, you fix it yourself!

To be fair, [Shahriar]’s Faxitron MX-20 digital X-ray microscope was only a little wonky. It still generally worked, but just took a while to snap into the kind of sharp focus that he needs to really delve into the guts of a chip. This one problem was more than enough to justify tearing into the machine, but not without first reviewing the essentials of X-ray production — a subject that we’ve given a detailed look, too — to better understand the potential hazards of a DIY repair.

With that out of the way and with the machine completely powered down, [Shahriar] got down to the repair. The engineering of the instrument is pretty impressive, as it should be for something dealing with high voltage, heavy thermal loads, and ionizing radiation. The power supply board was an obvious place to start, since electrostatically focusing an X-ray beam depends on controlling the high voltage on the cathode cup. After confirming the high-voltage module was still working, [Shahriar] homed in on a potential culprit — a DIP reed relay.

Replacing that did the trick, enough so that he was able to image the bad component with the X-ray imager. The images are amazing; you can clearly see the dual magnetic reed switches, and the focus is so sharp you can make out the wire of the coil. There are a couple of other X-ray treats, so make sure you check them out in the video below.

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Screwdrivers And Nuclear Safety: The Demon Core

August 15, 2023 by Al Williams 61 Comments

Harry Daghlian and Louis Slotin were two of many people who worked on the Manhattan Project. They might not be household names, but we believe they are the poster children for safety procedures. And not in a good way.

Harry Daghlian (CC-BY-SA 3.0, Arnold Dion)

Slotin assembled the core of the “Gadget” — the plutonium test device at the Trinity test in 1945. He was no stranger to working in a lab with nuclear materials. It stands to reason that if you are making something as dangerous as a nuclear bomb, it is probably hazardous work. But you probably get used to it, like some of us get used to working around high voltage or deadly chemicals.

Making nuclear material is hard and even more so back then. But the Project had made a third plutonium core — one was detonated at Trinity, the other over Nagasaki, and the final core was meant to go into a proposed second bomb that was not produced.

The cores were two hemispheres of plutonium and gallium. The gallium allowed the material to be hot-pressed into spherical shapes. Unlike the first two cores, however, the third one — one that would later earn the nickname “the demon core” — had a ring around the flat surfaces to contain nuclear flux during implosion. The spheres are not terribly dangerous unless they become supercritical, which would lead to a prompt critical event. Then, they would release large amounts of neutrons. The bombs, for example, would force the two halves together violently. You could also add more nuclear material or reflect neutrons back into the material.

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The Radioactive Source Missing In Australian Desert Has Been Found

February 1, 2023 by Lewin Day 66 Comments

Nuclear material is relatively safe when used, stored, and managed properly. This generally applies to a broad range of situations, from nuclear medicine to nuclear power generation. Some may argue it’s impossible to use nuclear weapons safely. In any case, stringent rules exist to manage nuclear material for good reason.

Sometimes, though, things go wrong, mistakes are made, and that nuclear material ends up going AWOL. That’s the situation that faced authorities in Australia, as they scoured over a thousand kilometers of desert highway for a tiny missing radioactive source with the potential to cause serious harm. Thankfully, authorities were able to track it down.

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Broken Genes And Scrambled Proteins: How Radiation Causes Biological Damage

January 24, 2023 by Dan Maloney 31 Comments

If decades of cheesy sci-fi and pop culture have taught us anything, it’s that radiation is a universally bad thing that invariably causes the genetic mutations that gifted us with everything from Godzilla to Blinky the Three-Eyed Fish. There’s a kernel of truth there, of course. One only needs to look at pictures of what happened to Hiroshima survivors or the first responders at Chernobyl to see extreme examples of what radiation can do to living tissues.

But as is usually the case, a closer look at examples a little further away from the extremes can be instructive, and tell us a little more about how radiation, both ionizing and non-ionizing, can cause damage to biochemical structures and processes. Doing so reveals that, while DNA is certainly in the crosshairs for damage by radiation, it’s not the only target — proteins, carbohydrates, and even the lipids that form the membranes within cells are subject to radiation damage, both directly and indirectly. And the mechanisms underlying all of this end up revealing a lot about how life evolved, as well as being interesting in their own right.

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New Study Tells Us Where To Hide When The Nukes Are Coming

January 19, 2023 by Lewin Day 70 Comments

Geopolitics is a funny thing. Decades can go by with little concern, only for old grudges to suddenly boil to the surface and get the sabers a-rattlin’. When those sabers happen to be nuclear weapons, it can be enough to have you mulling the value of a bomb shelter in your own backyard.

Yes, every time the world takes a turn for the worse, we start contemplating what we’d do in the event of a nuclear attack. It’s already common knowledge that stout reinforced concrete buildings offer more protection than other flimsier structures. However, a new study has used computer modelling to highlight the best places to hide within such a building to maximise your chances of survival.

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