Bent Electric Field Explains Antenna Radiation

We all use antennas for radios, cell phones, and WiFi. Understanding how they work, though, can take a lifetime of study. If you are rusty on the basic physics of why an antenna radiates, have a look at the very nice animations from [Learn Engineering] below.

The video starts with a little history. Then it talks about charges and the field around them. If the charge moves at a constant speed, it also has a constant electric field around it. However, if the charge accelerates or decelerates, the field has to change. But the field doesn’t change everywhere simultaneously.

Continue reading “Bent Electric Field Explains Antenna Radiation”

Warwalking For Radiation

Can’t find a recently updated survey of radioactivity in your neighborhood? Try [Hunter Long]’s DIY scintillation counter warwalking rig. (Video also embedded below.) What looks like a paint can with a BNC cable leading to an unassuming grey box is actually a complete kit for radiation surveying.

Inside the metal paint can is a scintillation counter, which works by attaching something that produces light when struck by ionizing radiation on the end of a photomultiplier tube, to make even the faintest hits “visible”. And the BNC cable leads to a Raspberry Pi, touch screen, GPS, and the high-voltage converters needed to make the photomultiplier do its thing.

The result is a sensitive radiation detector that logs GPS coordinates and counts per second as [Hunter] takes it out for a stroll. Spoilers: he discovers that some local blacktop is a little bit radioactive, and even finds a real “hot spot”. Who knows what else is out there? With a rig like this, making a radiation map of your local environment is a literal walk in the park.

[Hunter] got his inspiration for the paint-can detector from this old build by [David Prutchi], which used a civil-defense Geiger counter as its source of high voltage. If you don’t have a CD Geiger detector lying around, [Alex Lungu]’s entry into the Hackaday Prize builds a scintillation detector from scratch.
Continue reading “Warwalking For Radiation”

Global Radiation Montoring And Tracking Nuclear Disasters At Home

Many of us don’t think too much about radiation levels in our area, until a nuclear disaster hits and questions are raised. Radiation monitoring is an important undertaking, both from a public health perspective and as a way to monitor things like weapon development. So why is it done, how is it done, and what role can concerned citizens play in keeping an eye on things?

Continue reading “Global Radiation Montoring And Tracking Nuclear Disasters At Home”

Hackaday Podcast 032: Meteorite Snow Globes, Radioactive Ramjet Rockets, Autonomous Water Boxes, And Ball Reversers

Hackaday Editors Mike Szczys and Elliot Williams recorded this week’s podcast live from Chaos Communication Camp, discussing the most interesting hacks on offer over the past week. I novel locomotion news, there’s a quadcopter built around the coanda effect and an autonomous boat built into a plastic storage bin. The radiation spikes in Russia point to a nuclear-powered ramjet but the idea is far from new. Stardust (well… space rock dust) is falling from the sky and it’s surprisingly easy to collect. And 3D-printed gear boxes and hobby brushless DC motors have reached the critical threshold necessary to mangle 20/20 aluminum extrusion.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Direct download (41 MB)

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 032: Meteorite Snow Globes, Radioactive Ramjet Rockets, Autonomous Water Boxes, And Ball Reversers”

A Cheap And Cheerful Geiger Counter Build

Hackers often have broad interests across the sciences, of which nuclear topics are no exception. The Geiger counter remains a popular build, and could be a handy tool to have in a time of rising tensions between nuclear powers. [Leonora Tindall] had tinkered with basic units, but wanted a better idea of actual radiation levels in her area. Thus began the build!

The project began by leveraging the Geiger counter kit from the Mighty Ohm. [Leonora] had built one of these successfully, but wished for a visual readout to supplement the foreboding ticking noises from the device. This was achieved by installing a Metro Mini microcontroller along with a 4-character, 14-segment alphanumeric display. This, along with the cardboard enclosure, makes the build look like a prop from an 80s hacker movie. Very fitting for the Cold War-era technology at work.

By using a pre-built kit and upgrading it with display hardware, [Leonora] now has readings at a glance without having to reinvent the wheel and design her own board from scratch. Of course, if you’re thinking of taking on a more complex build, you might consider a scintillation detector instead.

Echos Of The Cold War: Nuclear-Powered Missiles Have Been Tried Before

On August 8th, an experimental nuclear device exploded at a military test facility in Nyonoksa, Russia. Thirty kilometers away, radiation levels in the city of Severodvinsk reportedly peaked at twenty times normal levels for the span of a few hours. Rumors began circulating about the severity of the event, and conflicting reports regarding forced evacuations of residents from nearby villages had some media outlets drawing comparisons with the Soviet Union’s handling of the Chernobyl disaster.

Today, there remain more questions than answers surrounding what happened at the Nyonoksa facility. It’s still unclear how many people were killed or injured in the explosion, or what the next steps are for the Russian government in terms of environmental cleanup at the coastal site. The exceptionally vague explanation given by state nuclear agency Rosatom saying that the explosion “occurred during the period of work related to the engineering and technical support of isotopic power sources in a liquid propulsion system”, has done little to assuage concerns.

The consensus of global intelligence agencies is that the test was likely part of Russia’s program to develop the 9M730 Burevestnik nuclear-powered cruise missile. Better known by its NATO designation SSC-X-9 Skyfall, the missile is said to offer virtually unlimited flight range and endurance. In theory the missile could remain airborne indefinitely, ready to divert to its intended target at a moment’s notice. An effectively unlimited range also means it could take whatever unpredictable or circuitous route necessary to best avoid the air defenses of the target nation. All while traveling at near-hypersonic speeds that make interception exceptionally difficult.

Such incredible claims might sound like saber rattling, or perhaps even something out of science fiction. But in reality, the basic technology for a nuclear-powered missile was developed and successfully tested nearly sixty years ago. Let’s take a look at this relic of the Cold War, and find out how Russia may be working to resolve some of the issues that lead to it being abandoned. Continue reading “Echos Of The Cold War: Nuclear-Powered Missiles Have Been Tried Before”

Fail Of The Week: Spinning The Pripyat Ferris Wheel

This multifaceted fail comes to us straight from the Chernobyl Exclusion Zone, where a group of friends apparently decided that a fun weekend project would be trying to turn over the iconic ferris wheel in the Pripyat Amusement Park. The [Kreosan] crew documented their admittedly very creative attempt at suicide in the video after the break, but we can save you some time by telling you right up front that the decades-old ferris wheel never actually rotates more than a few degrees. Though that’s hardly the key failure of this endeavour.

Even if you don’t understand anything they’re saying (we certainly don’t), it’s not too hard to follow along with this harebrained scheme.

Under cover of darkness, the troupe gains access to the mechanisms below the towering Soviet-era ride, and removes the brake unit mounted next to the motor. With the wheel now free spinning, the team is elated to see the mechanical advantage is such that spinning the shaft by hand is enough to cause a very slight rotation of the pulley and cables attached to the wheel.

Realizing they need more speed, the group then spends the rest of the night and apparently a good deal of the following day attempting to spin the mechanism using the rear wheel of one of their electric bicycles. But a rubber wheel held by hand against a rusty shaft, rather unsurprisingly, turns out to be a fairly poor mechanical linkage. They get a couple partial rotations on the pulleys, but still no serious movement.

One of the guys was working on the next phase of the inexplicably misguided plan, removing some heavy counterweights hanging under the ferris wheel, when a young woman shows up with a dosimeter and starts taking some measurements. Eventually, one of these moonlighting ferris wheel engineers uses the meter to observe the elevated radiation levels of the dirt and rust accumulated on his bare hands. This swiftly brings the operation to a close, and they all ride off on their bikes.

This was, without question, a monumentally stupid thing to do. Even if this was just a run-of-the-mill ferris wheel that had been abandoned and exposed to the elements for over thirty years, climbing on the thing and trying to get it to spin would be dangerous. But when you combine that with the fact it’s common knowledge to those who explore the Exclusion Zone that there are parts of the ferris wheel still emitting radiation at hundreds of times the normal background dose, this misadventure is a strong contender for the 2019 Darwin Award.

We’re lucky the remnants of Chernobyl’s number four reactor are locked away inside the Chernobyl New Safe Confinement, or else some up-and-coming Internet celebrity might try to get in there and spin up the turbines for a laugh. We’ve seen some pretty crazy stunts from [Kreosan], and we’d like to see more. So please, stay safe(r) guys!

Continue reading “Fail Of The Week: Spinning The Pripyat Ferris Wheel”