Focus Unfortunately, hopes for the success of the Hgl detector have dimmed somewhat from the time of its original conception. Birks still feels that "the Hgl detec tor will probably be coming on the market commercially." But Donald Leyden of Colorado State University, who has done a considerable amount of experimentation with Hgl detec tors, says that two major problems persist with this new technology: "It's all but impossible to get reproducible production of detector crystals, and even with the best electronics the res olution decreases dramatically with increasing count rate. I think now that people have all but thrown in the towel. For example, I know one com pany that was working on commercial izing this has put it on the shelf, and that shelf is pretty high and pretty dusty." At Kevex (not the same company), where the Hgl detector is currently a beta-test research product, marketing manager David Wherry also acknowl edges reliability problems, but he says that "there isn't anything fundamen tal we can see in the technology that would prevent the Hgl product from reaching the market at some point in
time. The technology is sufficiently promising to justify continuing efforts on our part." Of course, Hgl detectors have been shown to work, and some have oper ated successfully for several years. The problem, says Wherry, is that "If we build 100 detectors, six months later only half of them will be working. No one understands the mechanism by which these devices are degrading in their performance and why. That makes it difficult to make a commer cial product. But at the research scale this is a very nice little product." Whither the Hgl detector? It's a technology that is generating mixed signals at this point. It's close enough to reality to be interesting, but it has serious problems that make its immi nent commercialization unlikely. Suggested reading
Bertin, Eugene P. "Introduction to X-Ray Spectrometric Analysis"; Plenum Press: New York, N.Y., 1978. "Energy-Dispersive X-Ray Microanalysis: An Introduction"; Kevex Corporation: Foster City, Calif., 1983. Jenkins, Ron. Anal. Chem. 1984,56, 1099-1106 A. S.A.B.
Software Collection Planned i The Blacksburg Group, Inc., a firm that writes and publishes books about I using small computers, is planning a j collection of useful scientific routines S and subroutines. According to Jona- : than Titus, president of The Blacksburg , Group, this book will give people who j have written interesting programs a ; chance to share these programs with j other scientists. The Blacksburg Group is looking I particularly for short programs written in BASIC that have specific purposes, I such as numerical analysis, graphing, j and printer control routines. All re- j sponses will be answered, and all j programs will be treated in confidence, j The author will retain the copyright and | will be free to offer the program for [ sale on disk or to a magazine for serial publication. Compensation has not j been determined yet; this will depend | somewhat on the length and type of j programs received. s If you are interested in submitting a j program, contact The Blacksburg ' Group, Inc., P.O. Box 242, Blacksburg, 1 Va. 24060; phone 703-951-9030. M.D.W. !
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CIRCLE 138 ON READER SERVICE CARD ANALYTICAL CHEMISTRY, VOL. 57, NO.
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