Source: The Vancouver Sun

    Discovery of British Columbia physicist could well revolutionize the forest industry.

University of Northern B. C. physics professor Matt Reid with students such as Tara Todoruk and other collaborators are trying to create devices that use terahertz waves to see inside wood.
Photograph by : Vancouver Sun, Handout photo

    When University of Northern B.C. physicist Matt Reid decided to examine a block of wood in his lab using a burst of terahertz waves ¡ª a more refined and benign form of radiation than X-rays ¡ª he was driven by both curiosity and his upbringing in timber-dependent Prince George.

    What he saw was an image of the long cellulose fibres the way nature had laid them down as the tree grew. He saw far more detail than the simple dark patches that would show density in an X-ray image. Using different colours, he could see if the fibres were aligned or twisted, almost as if he were looking at the wood grain from the outside.

    Reid realized he was seeing something that could revolutionize the forest industry of his home town.

    If operators could see inside wood, they could make stronger products and get straight lumber out of the dried, cracked and twisted timber that the mountain pine beetle has left in its wake across the central Interior. Sawmills are finding it increasingly difficult to get enough quality boards out of the timber to justify harvesting it.

    It was a fluke, Reid said of his decision to put wood under terahertz radiation. Called T-rays, they occupy a space on the electro-magnetic spectrum between X-rays and microwaves, and are becoming a focus of international research because they can reveal clear images without producing harmful radiation.

    It was 2003 and he was working on his PhD at the University of Alberta, a leading centre for research in terahertz waves.

    ¡°I was putting a whole bunch of things in there, and one of the things I put in was a shelf, which was made out of wood, and, as it turned out, I could see through it, which surprised me.¡±

    The surprise discovery had nothing to do with his research project ¡ª he was actually examining crude oil. But what he saw opened up a whole new world of possibilities where terahertz technology could be used in Interior sawmills to actually see the inside of beetle-damaged logs.

    Reid is a leading terahertz researcher and was part of a team that recently captured a world record for producing bursts of terahertz waves with the largest energies ever recorded.

    At Montreal¡¯s Advanced Laser Light Source facility, the team used ultra-fast lasers to produce their burst of T-rays, which gave them the ability to see right through objects in real time.

    Terahertz waves have been the subject of research for 20 years. But because they have a short range, it was not until the 1990s that the technology was developed to produce and detect coherent terahertz radiation. Initially, researchers could penetrate no further than the thickness of a piece of paper.

    The science is still in its infancy, but with more advanced technical tools, researchers like Reid are scrambling to be the first to find an industrial application for T-rays.

    Reid expects terahertz waves will soon replace X-rays in hospitals and be installed at airports, where they would show more detailed images, exposing features within people or objects under their clothing without producing radiation side-effects.

    Reid¡¯s goals are more simple. He is focussed on bringing the technology to his own part of the world, where the window for finding economic options for beetle-killed timber is beginning to close.

    ¡°With all of the mountain pine beetle-killed wood that¡¯s coming out now, one of the things that¡¯s really important is to determine what can be done with that wood,¡± Reid said. ¡°Because, as the fibre deteriorates, you won¡¯t be able to make a very good two-by-four out of it.¡±

    Reid is now developing several patents and working with Bruce Sutherland, of Wolftek Industries in Prince George to create camera-like devices using terahertz waves to see inside wood.

    Sutherland said the possibilities are endless.

    ¡°We have kept this under wraps until now,¡± he said in an interview. ¡°It¡¯s not smoke and mirrors. This could be very solid. The possibilities are worth millions of dollars.¡±

    Sutherland said the mountain pine beetle¡¯s impact on sawmilling has been costly. Boards are shattering on the production line because the grain has a slope to it that cannot be identified before the log is cut. And when a board shatters, the line has to be shut down and cleared, wasting valuable production time.

    Sutherland, an entrepreneur with practical forest industry experience, said he can see the day when mills and oriented strand board plants ¡ª whether they are using beetle wood or not ¡ª could stamp their products certifying their internal strength once they have been scanned by terahertz cameras.

    The technology Reid has developed to this point can see through boards, solving the problem of weak boards shattering on the production line. Research is under way to reach the point where he can see through a whole log.

    Reid said also believes T-rays can aid in producing oriented strand board, a panel product made by laying down layers of fibre wafters on top of each other. Each layer is oriented at 90 degrees to the layer below. But they don¡¯t always fall perfectly aligned onto the mat.

    Reid believes if producers had a means of seeing how well the layers are being oriented by viewing the inside of the panel as it is being made, they would be able to make a stronger product.

    Gary Crooks, of the Council of Forest Industries, described Reid¡¯s research as timely and interesting. But there are a lot of steps to be taken before it could be applied in sawmills or OSB plants, he said.

    ¡°There are various technologies that could be of assistance to the mill operators, but this is the first I have heard of this one,¡± he said.