Detecting Cosmic Rays With 18 Geiger Tubes

June 16, 2012 by 21 Comments

What do you do if you have 18 Geiger tubes lying around? [Robert] had an interesting idea to build a cosmic ray detector and hodoscope to observe the path cosmic rays take while flying through his lab.

[Robert]’s cosmic ray detector works by detecting the output 9 Geiger tubes on the y-axis and 9 Geiger tubes on the x-axis with a coincidence circuit. When a cosmic ray flies through the detector, it should trigger two tubes simultaneously. By graphing which of the two tubes were triggered on an array of 81 LEDs, [Robert] not only knows when a cosmic ray is detected, but where the cosmic ray was.

The detectors do pick up a little background radiation, but thanks to [Robert]’s coincidence circuit, he can be fairly certain that what he’s recording are actually high-energy cosmic rays.

Before building the 9×9 hodoscope, [Robert] built a similar drift hodoscope that simply plots the path a cosmic ray takes through an array of Geiger tubes. You can check out videos of both these cosmic ray detectors after the break.

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Turn Your Camera Phone Into A Geiger Counter

January 15, 2012 by 96 Comments

Next time you’re waiting in the security line in an airport, why don’t you pull out your smartphone and count all the radiation being emitted by those body scanners and x-rays? There’s an app for that, courtesy of Mr. [Rolf-Dieter Klein].

The app works by blocking all the light coming into a phone’s camera sensor with a piece of tape or plastic. Because high energy radiation will cause artifacts on the CMOS camera sensor inside the phone, radiation will be captured as tiny specks of white light. The title picture for this post was taken from a camera phone at the Helmholtz Research Center in Munich being bathed in 10 Sieverts per hour of Gamma radiation from the decay of Cesium-137.

We have to note that blips of ‘bad data’ from a CMOS camera sensor aren’t unusual. These can come from electrical weirdness in the sensor itself or even the heat from the battery. [Rolf]’s app takes a reading of the noise floor and subtracts it from the counter. Radioactive decay resulting in Beta particles such as the Potassium-40 in bananas or the Uranium in granite counter tops don’t really register, although [Rolf] did have some success with Potassium chloride and a long measurement time. Still though, it’s a really cool way to turn a phone into a tricorder.

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USB Geiger Counter Hack

May 13, 2011 by 17 Comments

usb_geiger

[Vic] bought a Kvarts DRSB-01 Geiger counter a few years ago, and recently dug it out of his electronics stash. The counter is a run of the mil no-frills unit. It lacks any kind of LCD display and it cannot be calibrated, so Sievert exposure ratings are out of the question. The unit essentially monitors background radiation and alerts the user to the presence of gamma and high-energy beta rays via audible clicks.

[Vic] wanted to make it a bit more useful, so he decided to interface it with his computer in order to take long-term radiation measurements. He dug up a schematic online and deadbugged a small circuit using an ATtiny44. The circuit allows him to enumerate the electrical pulses generated by ionizing particles striking the Geiger tube, passing them along to his PC over USB.

The counter seems to interface with the PC just fine, but [Vic] does say that he’s getting some odd readings. He thinks that he might have damaged the tube while messing around, but he’s all ears if you have any insight on the matter.

Geiger Counter Built In An Ohmmeter Enclosure

April 7, 2011 by 4 Comments

Here’s a Geiger Counter that makes itself at home inside of an old Ohmmeter (translated). [Anilandro] set out to built this radiation detector in order to learn how they work. Like other diy Geiger Counter builds we’ve seen, this project assembles a circuit to interface with a gas-filled tube which serves as the detector. [Anilandro] takes a few paragraphs to discuss how this works; the Geiger tube is basically a capacitor whose electrical characteristics change as an ionizing particle passes through it.

Once he had the theory worked out he scavenged some parts to use. A broken emergency light donated its transformer to provide the high voltage needed. The rest of the circuit was built on some protoboard, and a speaker was added to output the clicking noises that have become a familiar part of the detector hardware. The tube itself is housed in a wand that attaches to the base unit through a cable. Check out some test footage of the finished unit after the break.

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Geiger Counter A/D Conversion For Radiation Level Crowdsourcing

March 23, 2011 by 17 Comments

arduino_geiger_counter

[Akiba] and the crew at Tokyo Hakerspace are still hard at work trying to help out their fellow countrymen after the recent earthquake, tsunami, and ongoing nuclear crisis in Japan. You may remember the group as they are behind the Kimono Lantern project we featured last week. This time around, their efforts are focused on getting usable information out to those who need it.

With all of the talk about nuclear fallout, they wanted to see what sort of measurements they could get in Tokyo, however they could not locate a Geiger counter anywhere nearby. Luckily, they were eventually able to source two old counters from the Reuseum in Idaho. One is being lent out to individuals in order to check if their home’s radiation levels are safe, but it was decided that the other would reside outdoors in order to collect radiation readings from the air.

[Akiba] wanted to put the results from the external Geiger counter up on Pachube, however these old units are all analog. He figured that a quick and dirty way to do analog to digital conversion would be to monitor the chirps coming off the counter’s speaker. This was done by wiring up an Arduino to the speaker leads, and keeping track of each time the speaker was activated. This resulted in an accurate digital radiation reading, matching that of the counter’s analog display. The Arduinio wirelessly sends the information to another Arduino stationed inside his apartment, which then uploads the data to Pachube.

A walkthrough of his conversion as well as the source code for both the Arduino counter and the Pachube uploader are available on his site, in case anyone else in the Tokyo area has a Geiger counter handy and wishes to do the same.

Hackable Geiger Counter

October 21, 2009 by 41 Comments

SFE_Geiger_Counter

[Aaron] A.K.A. [A1ronzo] at SparkFun has put together a hackable USB Geiger Counter. In his tutorial, he gets the Geiger counter to work as a random number generator. Later, he analyzes and discusses how well it works as a random number generator.  In the past, we have seen a number of radiation detectors hacks such as the Mr. Fission digital Geiger counter, a count accumulator, and a Polonium detecting pen,  Besides our inital thoughts of speeding up the number generation, and using it as a special character device, what else can you come up with to do with this device?

Digital Geiger Counter

November 19, 2007 by 12 Comments


Worried about radiation levels? I’m not, but I still want to build one of these. Mr. Fission here was built by the same guy that’s behind the OpenTracker project. [Scott] based it on the Bargraph Geiger counter built by [Russel E. Cliff]. Both use a standard Geiger tube like the LND712. The tube works with high voltages – easy enough with older electronics, but it’s a slightly tougher challenge with todays low voltage gear. [Scott] used the high voltage power supply from the original project, and built the rest around a good ol’ Motorola HC86 series processor. [Scott]’s idea of using an inverter supply designed for a cold cathode lamp is definitely an interesting one.