(Page 2 of 2)
User interface: The researchers developed software to operate the telescope and analyze data in real time.
University of New Hampshire
The telescope comprises two different cylinder-shaped "scintillation" detectors that work in tandem, surrounded by large glass photomultiplier tubes. When a gamma ray hits the front detector, the energy is scattered and absorbed by the rear detector. The energy is then converted into visible light and detected by the highly sensitive photomultiplier tubes. The specific color and intensity of the light can identify the radioactive material involved, says Gerald Share, a visiting senior research scientist in the department of astronomy at the University of Maryland, who was not involved in the work.
"The instrument measures how much energy is deposited in each detector to calculate the total energy of the gamma ray," says Ryan. "This tells you what the radioactive isotope is." The researchers have hooked up the telescope to a laptop and developed software that is easy to control.
The researchers will present their work at the 2009 IEEE International Conference on Technologies for Homeland Security. "Since the 9/11 terrorist attacks, we realize we are in a dangerous world, and it is essential to put money into technologies like this," says Share. "We have no other choice."
Ryan says that the telescope could be used in a variety of national-security settings, such as for cargo inspections and to search for rogue nuclear weapons.
Small, implantable devices could measure radiation from within tumors themselves.
Researchers integrate refraction information to improve x-ray resolution.
A new device, with sensors the size of human cells, can measure, record, and assess the risk of radiation emissions in real time.
The halving distance for a gamma ray in air is no more than 200 meters. In 10 to 20 halving distances the gamma ray source is not detectable. So the range of a detector is about 4000 meters at most. So no satellite can detect a gamma ray source on earth from space. That is the reason why they put gamma ray observatories in orbit in the first place; to get above the earth's atmosphere.
Guest (jguerrier)
Sorry folks they have not repealed 1/radius squared relating to the detection of electromagnetic energy.
If you read the article you find that the gamma ray telescope is mounted on a terrestrial vehicle (truck). The output from a weapon amount of U-235 is still completely attenuated by an insignificant amount of simple shielding material. Medical Isotopes that could be employed as dirty bomb can be concealed in the interior of a standard shipping container and shielded to the degree that detection would be difficult.
There are scintillation and solid state gamma ray detection systems currently in use that will rival if not outperform this gamma ray telecsope.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
This document is part of the “How-To Guide for Most Common Measurements” centralized resource portal. This tutorial provides a detailed guide for measurement and device considerations to take temperature measurements using thermocouples. Get an introduction to thermocouples, which are inexpensive sensing devices widely used with PC-based data acquisition systems. Also review some specific thermocouple examples and learn how thermocouples work and ways to integrate them into a data acquisition measurement system.
View full PDF >
Listen to story > 
Our list of the 50 most innovative companies, including the following:
On Twitter
Become a Fan on Facebook
Subscribe to the Feed
jojo99
12 Comments
Dirty bombs
If we can detect gamma rays and such from billions of light years away, why couldn't a similar device be mounted in a satellite pointed at the Earth's surface?
Reply
makornitzky
17 Comments
Re: Dirty bombs
Detector in a satellite ... Who says there aren't detectors up there already?
Reply
Pjazzz
14 Comments
Re: Dirty bombs
relax folks....the detectors are already up there, and there are enough of them pointed at "appropriate" areas, in the US and elsewhere.
Reply