Fred Schamber, EDS pioneer, passes away

Fred Schamber, one of the early pioneers of quantitative energy dispersive X-ray spectrometry and a significant contributor to the field throughout his life, passed away on the 25^th of February 2024.  Fred entered the field of X-ray microanalysis after earning a Ph.D. in health physics at Fermilab.  In 1972, he joined Jon McCarthy at Tracor Northern bringing with him experience in low-level radiation counting.  At Tracor Northern, they helped to develop some of the early classic energy dispersive X-ray microanalysis products including the TN-product line and the Flextran instrument control computer language.  Flextran became the basis for many third-party utilities like Sandia Lab’s SANDIA TASK8 which provided early SEM automation and Doyle and Chamber’s ZAF80 which provided matrix correction algorithms.

It is easy to forget just how primitive computers were in the early-1970’s.   Fred would describe how they would hand manufacture magnetic core memory using sewing needles and magnetic beads to construct 4k bit blocks of RAM.  He described how they would turn cathode ray screens on their side because the form factor was deemed better for displaying spectra.  The TN-product line had some of the first use of color displays.

Regardless, in 20k or less of RAM on computers with sub-1 MHz cycle times, they were able to collect, process and quantify X-ray spectra.  On a computer this size and speed, the code needed to be both time and byte efficient.  His answer to the difficult question of how to separate the continuum signal from the characteristic remains to this day the fastest and most accurate way to extract k-ratios from EDS spectra.  Using the so-called “top-hat” filter to remove both high and low frequencies, he was able to extract the characteristic signal from unknown and standard and perform a linear fit of one against the other.  When he first presented his algorithm at an early EPASA meeting, there were those in the audience who took him to task for claiming to be able to extract quantitative data from EDS spectra.  Of course, Fred was right and within a year or two he had converted his critics.

Later at Tracor-Northern, he led the skunk-works development of an instrument that was many years ahead of its competitors – the ADEM (automated digital electron microscope).  Fred would later admit that the ADEM might have been a little over-engineered.  It had an enormous chamber with a sturdy five axis motorized stage.  It was an entirely digital and software-based instrument when analog electronics were the norm.  Each sub-system was controlled by its own microcontroller, an expensive rarity.  In the days when wavelength spectrometers were positioned by hand, ADEM offered electronically controlled positioners under software control.  Because of the computer control and Fred’s experience developing automation for the TN-product line, the ADEM excelled at computer automated electron microscopy.  It was often used to analyze environmental particle samples like fly ash.

After 18 years with Tracor Northern, in 1990, Fred joined Rich J. Lee to form the instruments division of RJ Lee Group.  Here, Fred lead the development of the Personal SEM.  The vision was to take the innovations, size and cost reductions that came with the Personal Computer revolution to scanning electron microscopy.  The Personal SEM was a simple, inexpensive moderate performance SEM.  From day 1, the Personal SEM was designed to be computer automated.  Due to tight integration between the scan controller and the computer, it was possible to implement fast, efficient particle search and measure algorithms.  RJ Lee Group’s scientists served as design consultants and beta testers.  For many years, the Personal SEM and its successors became the go-to instrument for automated particle analysis including forensic gun-shot residue.  The Personal SEM went places few SEMs could.  They could be found next in iron foundries and aircraft hangers.   ASPEX developed a special SEM-in-crate to go in military aircraft hangers in the Persian Gulf at temperatures exceeding 90° F to characterize jet engine wear debris.  RJ Group Instrument Division became RJ Lee Instruments and eventually ASPEX.  ASPEX was bought out by FEI which was then bought out by Thermo Fisher.  The manufacturing which had been performed in Delmont outside of Pittsburgh was moved to the Czech Republic.

For his numerous contributions, Fred was made a fellow of the Microanalysis Society.

Fred retired at the end of 2014.  In retirement, Fred and his wife Julia invested their energies in the Lutheran Marriage Encounter Ministries and Fred loved to fly fish.  Fred is survived by his wife Julie and his children Doug, Pam and Kim.  He will be missed by all who knew him.

Authored by: Nicholas Ritchie