While we’ve seen developments that could see T-ray spectrometers featuring in a future handheld tricorder-like device, good ol’ X-rays could also get a guernsey thanks to an engineering team from the University of Missouri. The team has invented an accelerator about the size of a stick of gum that can create X-rays and other forms of radiation, opening up the possibility of cheap and portable X-ray scanners.
As well as being small, the device requires just a fraction of the electricity used by current X-ray machines. Using a crystal made from lithium niobate, it uses the piezoelectric effect to amplify an electrical input of 10 volts to produce more than 100,000 volts of electricity. This could allow the crystal to be powered by batteries in a handheld device.
“Currently, X-ray machines are huge and require tremendous amounts of electricity,” said Scott Kovaleski, associate professor of electrical and computer engineering at MU. “In approximately three years, we could have a prototype hand-held X-ray scanner using our invention. The cell-phone-sized device could improve medical services in remote and impoverished regions and reduce health care expenses everywhere.”
In addition to potentially putting an X-ray scanner in every doctor’s office, Kovaleski says the technology has a wide variety of potential applications. It could improve border security by allowing more widespread searching of cargo at border crossings, while the size and low energy requirements of the technology would also be perfect for inclusion on future interplanetary probes, like the Curiosity rover.
Closer to home, Kovaleski says the device could also allow dentists to take X-rays from the inside of the mouth so that the rays are shooting outward, rather than exposing the patient’s head to harmful radiation.
Because the accelerator is able to create forms of radiation other than X-rays, it also has the potential to replace the radioisotopes used in drilling for oil and in other industrial and scientific operations. Additionally, the device offers a safer source of radiation as it can be turned off in the event of an emergency.
“Our device is perfectly harmless until energized, and even then it causes relatively low exposures to radiation,” said Kovaleski. “We have never really had the ability to design devices around a radioisotope with an on-off switch. The potential for innovation is very exciting.”
The technology is detailed in a paper published in the journal IEEE Transaction on Plasma Science.
Source: University of Missouri
So don't expect a small handheld device with which you can make "x-ray photos". (Low power means longer measurement times...) Nor will this device decrease the dose what you get during medical examinations. (That is determined mainly by the detectors, which require a certain dose to form a proper image.)
In most cases the question is not "How to decrease electrical power input?", rather "How to increase it without melting the anode?". Without new, drastically more efficient detectors, the possible applications for this device are very limited. You need to find a niche where measurement time is not a priority, but the weight of the device is. Screening at airports or at doctor's offices are not such applications. Space probes, and small, portable XRF spectrometers might be the ones to utilize this invention.
That's a nice essay, but the problem is that you're thinking of this in terms of the old technology you know. There isn't enough information in the abstract to really know, but it seems like this generates electron beams in a fundamentally different way, without exposed cathodes and anodes. Sort of like the difference between vacuum tubes and semiconductor devices. It would be foolish to dismiss solid state devices by basing assumptions on what you know about vacuum tubes.
Generating an electron beam is not such a difficult thing, and it does not consume to much power either. (A few watts from the hundreds or thousands of watts, consumed by the source...) The rest is used to accelerate the electrons to high energies. The real problem is, that converting the energy carried by the electrons to X-rays is very inefficient. In most cases the electron beam is directed to a metal surface, and it produces bremsstrahlungh or characteristic X-rays. The problem is that only about 1% of the energy of the electrons is transformed to X-rays. The rest is turned into heat. And in this respect this new source is not different from the old ones. The article claims that X-rays were produced by bremsstrahlung when the electron beam struck the stainless steel wall of the vacuum chamber. As it uses the same effect to produce X-rays as traditional sources, there is no reason to believe this is more efficient than the old ones.
And it is not a solid state device either. Small (1 mm long, 0.1 mm in diameter) platinum-iridium wires were glued to the end of the piezoelectric crystal. They served as cathodes. The anode was the wall of the vacuum chamber. Between the two electrodes the electrons flew in vacuum. I admit, that 1E-3 torr (which was enough for this device to operate) is much higher than the pressures required by traditional X-ray sources, and this might be an advantage, but this is still a vacuum tube, and not a solid state device.
As I see, the novelty of this device is the way it produces the high voltage, which is required to accelerate the electrons. Using a piezoelectric crystal instead of traditional electronics is a good idea, and it makes it possible to integrate the high voltage supply into the vacuum chamber. But still: it generates X-rays in pretty much the same way as traditional X-ray sources.
@nutcase You don't need an X-ray source for that. Your phone will do it for you... :(