Author Topic: History of EPMA  (Read 26174 times)

Anette von der Handt

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Re: History of EPMA
« Reply #15 on: February 27, 2018, 01:43:10 PM »
This video is described as showing an electron probe magnifier from the 1960's. It might be an SEM though. Anyone can recognize a make/model? What is that rotating turret at the end?

https://www.youtube.com/watch?v=i2oyzt98oc0
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AndrewLocock

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Re: History of EPMA
« Reply #16 on: February 27, 2018, 04:03:19 PM »
Hello,

A snapshot of the early history of electron microprobe manufacturers may be found in Table 18 of Beaman, D.R. & Isasi, J.A. (1972) Electron Beam Microanalysis. ASTM Special Technical Publication 506. This table (attached) lists the various manufacturers, their common acronyms, and then-current U.S. addresses.

A handy figure that shows the various takeoff angles for X-rays in many early instruments can be found in Figure 2 of Smith, D.G.W. & Rucklidge, J.C. (1973) Electron microprobe analysis in the earth sciences. Advances in Geophysics 16, 57-154. I have also attached this file to this post.

Cheers,
Andrew


AndrewLocock

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Re: History of EPMA
« Reply #17 on: February 27, 2018, 04:25:57 PM »
Further early history: 11 manufacturers (including MAC) are listed in the table given in Wittry, D.B. (1969) Recent Advances in Instrumentation for Microprobe Analysis. In: Möllenstedt G., Gaukler K.H. (eds) Vth International Congress on X-Ray Optics and Microanalysis. Springer, Berlin, Heidelberg. A copy in PDF format of the table is attached.

Probeman

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Re: History of EPMA
« Reply #18 on: March 03, 2018, 01:54:27 PM »
I'm still enjoying reading "The Disappearing Spoon- and other true tales of madness, love, and the history of the world from the periodic table of the elements"- whew, long title.

There's the story of how Monte Carlo calculations came to be (named).  Basically Stanislaw Ulam who played solitaire card games starting wondering what the chances of winning any randomly dealt hand were. That led to discussions with John von Neumann about such calculations, when they realized that this idea could be applied to all sorts of problems with lots of random variables. After all quantum mechanics are strictly probabilistic.  And computers were just becoming able to handle these types of calculations.

The naming of this calculation method is not completely clear according to the author, but he states that "historically, the science of probabilities has roots in aristocratic casinos, and Ulam liked to brag that he named it in memory of an uncle who often borrowed money to gamble on the "well known generator of random integers (between zero and thirty six) in the Mediterranean principality"".
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Jacob

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Re: History of EPMA
« Reply #19 on: October 14, 2018, 05:48:04 PM »
I actually started on an ARL SEMQ at UC Berkeley in the mid 1980s as a mechanical technician.   It was an "interesting" instrument to say the least.  After a student managed to implode the vacuum chamber (let's call it an explosive depressurization, a long story), the electronics tech and I rebuilt it completely.  It was an education in EPMA I can tell you. It was after that when I realized the software needed to be improved. The rest is history as they say.

Looking at the new Shimadzu literature on their EPMA-1720, it looks like the spectrometers accept xrays from above the objective lens.  Were the ARL probes like that?  It's a very interesting design.  Does anybody else do it that way?

Probeman

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Re: History of EPMA
« Reply #20 on: October 15, 2018, 10:52:44 AM »
I actually started on an ARL SEMQ at UC Berkeley in the mid 1980s as a mechanical technician.   It was an "interesting" instrument to say the least.  After a student managed to implode the vacuum chamber (let's call it an explosive depressurization, a long story), the electronics tech and I rebuilt it completely.  It was an education in EPMA I can tell you. It was after that when I realized the software needed to be improved. The rest is history as they say.

Looking at the new Shimadzu literature on their EPMA-1720, it looks like the spectrometers accept xrays from above the objective lens.  Were the ARL probes like that?  It's a very interesting design.  Does anybody else do it that way?

Hi Jacob,
Yes, it is an interesting design. Everyone else seems to have settled on a 40 degree takeoff angle accepting x-rays from underneath the objective lens. The ARL/Shimadzu was designed that way to obtain a very high takeoff angle of 52.5 degrees (if you've ever seen this angle and wondered where it comes from, it's from the ARL/Shimadzu design).  One advantage is smaller matrix corrections, for example F Ka in CaF2 at 40 degrees:

SAMPLE: 32767, TOA: 40, ITERATIONS: 0, Z-BAR: 14.64681

 ELEMENT  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR STP-POW BKS-COR   F(x)u      Ec   Eo/Ec    MACs
   Ca ka  1.0024  1.0000  1.0134  1.0158  1.0505   .9646   .9606  4.0390  3.7138 153.760
   F  ka  3.2329   .9998   .9795  3.1661   .9449  1.0366   .2318   .6870 21.8341 6822.03

 ELEMENT   K-RAW K-VALUE ELEMWT% OXIDWT% ATOMIC% FORMULA KILOVOL                                       
   Ca ka  .00000  .50536  51.335   -----  33.333   1.000   15.00                                       
   F  ka  .00000  .15371  48.665   -----  66.667   2.000   15.00                                       
   TOTAL:                100.000   ----- 100.000   3.000

And here at 52.5 degrees:

SAMPLE: 32767, TOA: 52.5, ITERATIONS: 0, Z-BAR: 14.64681

 ELEMENT  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR STP-POW BKS-COR   F(x)u      Ec   Eo/Ec    MACs
   Ca ka  1.0019  1.0000  1.0134  1.0153  1.0505   .9646   .9679  4.0390  3.7138 153.760
   F  ka  2.7944   .9998   .9795  2.7366   .9449  1.0366   .2825   .6870 21.8341 6822.03

 ELEMENT   K-RAW K-VALUE ELEMWT% OXIDWT% ATOMIC% FORMULA KILOVOL                                       
   Ca ka  .00000  .50559  51.335   -----  33.333   1.000   15.00                                       
   F  ka  .00000  .17783  48.665   -----  66.667   2.000   15.00                                       
   TOTAL:                100.000   ----- 100.000   3.000

This originally American designed/made instrument was innovative in several ways, but it also had some significant issues for example, very small Bragg crystals which was only partially compensated for by using a very small (127 mm) focal circle.  But the ability to have six tunable spectrometers is very attractive from an analytical perspective, if fact that is why Probe for EPMA still has the capability of handling six spectrometer instruments!
« Last Edit: October 15, 2018, 02:51:12 PM by Probeman »
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Probeman

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Re: History of EPMA
« Reply #21 on: November 30, 2018, 10:57:47 AM »
I'm compiling a list of (dead) people that should be mentioned in the history of EPMA.

I have:
Hans Bethe (for electron energy loss)
J. J. Thompson (for discovery of the electron)
Wilhelm Röntgen (for the discovery of x-rays)
Henry Mosely (for discovery of atomic number and wavelength relationship)
Raimond Castaing (for invention of EPMA instrument and physical basis of matrix corrections)

Any others come to mind?
john
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Probeman

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Re: History of EPMA
« Reply #22 on: November 30, 2018, 03:37:48 PM »
John - you're list is going to be a long one, but for starters:

William Lawrence and William Henry Bragg (Braggs' Law)
Andre Guinier (Guinier XRD cameras and Castaing's PhD supervisor)
August Beer (X-ray attenuation)
Frans Michel Penning (cold-cathode vacuum gauges)
Max Planck (Planck's law)
Ernst Ruska/Max Knoll/Manfred von Ardenne (scanning electron beams)
Walter Schottky (Schottky effect)

Doh!  Of course the Bragg father/son duo is sorta obvious.  Thanks!
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John Donovan

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Re: History of EPMA
« Reply #23 on: December 08, 2018, 03:02:47 PM »
John - you're list is going to be a long one, but for starters:

William Lawrence and William Henry Bragg (Braggs' Law)
Andre Guinier (Guinier XRD cameras and Castaing's PhD supervisor)
August Beer (X-ray attenuation)
Frans Michel Penning (cold-cathode vacuum gauges)
Max Planck (Planck's law)
Ernst Ruska/Max Knoll/Manfred von Ardenne (scanning electron beams)
Walter Schottky (Schottky effect)

OK, we added some more birthdays of famous people in EPMA to the "special greeting" list in Probe for EPMA.  There are several in December. Maybe you will find out who they are!
« Last Edit: December 08, 2018, 03:06:49 PM by John Donovan »
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Probeman

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Re: History of EPMA
« Reply #24 on: January 07, 2019, 10:20:35 AM »
I am saddened to receive this notice on the passing of Dr. Robert (Bob) Tracy:

Quote
Dear Faculty, Staff, and Students:

With great sadness, I must inform you that Dr. Bob Tracy passed away late last night.

Bob has been a stalwart of our department for many years, having served as both a professor and department head.  He was a generous colleague, a connoisseur of wine and monazite, a peerless microprobe-whisperer, and a selfless mentor to students and junior faculty alike.  He leaves a void that will be impossible to fill.

At the end, Bob’s wife Pat was with him, and he had been visited by several close friends from the department, including Mark and Kristie Caddick, Nancy Ross, and Maddy Schreiber.

While this is a sad day for our department, at an appropriate point in the future we will hold a memorial event that will celebrate Bob’s life and his many contributions to the Department of Geosciences, the College of Science, and Virginia Tech.

Steve

____________________________

W. Steven Holbrook
Professor and Head
Department of Geosciences
Virginia Tech
926 West Campus Drive
4044 Derring Hall MC 0420
Blacksburg, VA  24061

wstevenh@vt.edu
http://www.steveholbrook.com
540-231-6521 (voice)
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JohnF

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Re: History of EPMA
« Reply #25 on: January 11, 2019, 07:26:43 AM »
Begin forwarded message:

From: Mark Caddick <caddick@VT.EDU>
Subject: Bob Tracy
Date: January 10, 2019 at 12:09:24 PM CST
To: <GEO-METAMORPHISM@JISCMAIL.AC.UK>
Reply-To: Metamorphic Studies Group <GEO-METAMORPHISM@JISCMAIL.AC.UK>, Mark Caddick <caddick@VT.EDU>

Dear All,

It is with profound sadness that we write to inform you of the loss of our friend and colleague Robert (Bob) Tracy, who died at his home in Blacksburg early on Sunday morning.  Bob is survived by his wife of 50 years, Patricia.

Bob was a metamorphic petrologist whose thinking always stemmed from the deepest understanding of mineral structure and chemistry, and from a delight in the beauty of phase equilibria.  He made important contributions to our understanding of the measurement and significance of chemical zoning in metamorphic minerals, of metamorphic phase equilibria, of the processes of crustal melting and the mineralogy of residual rocks, of the behavior of sulfur during metamorphism, of microprobe dating of monazite, and of the tectono-metamorphic evolution of New England.  More importantly, Bob was a generous colleague, an enthusiastic teacher, and a fiercely loyal friend to the petrologic community.

Bob was born in Washington, D.C., in 1944.  He obtained his A.B. degree from Amherst College in 1967 before receiving an M.S. from Brown University in 1970 for work that first introduced him to the Cortlandt Complex of New York State – rocks that he would continue to work on throughout his career.  Bob’s Ph.D. (1975) was from the University of Massachusetts at Amherst under the supervision of Peter Robinson, focusing on metamorphic reactions and partial melting in pelitic schists of the Quabbin Reservoir Area, MA.  He then moved to Harvard as a research fellow, during which time he published influential work with Alan Thompson on anatexis in pelitic rocks and inferring metamorphic histories from chemical zoning in garnet.  Bob moved to Yale in 1978 as an assistant and then associate professor and moved to Virginia Tech in 1986 as full professor.  Bob was a great departmental citizen, serving as Department Chair from 2005 and 2008 and as Associate Chair from 2012 to 2018, and devoted much time to looking after and nursing along aging electron microprobes from which he was able to extract phenomenal data.  He was also extremely active in professional societies, in particular the Geological Society of America, in which he assumed numerous leadership roles.

Despite Bob's substantial and diverse research and service contributions, he will be known to many students because of his co-authorship with Harvey Blatt on the second edition of the textbook "Petrology: Igneous, Sedimentary, and Metamorphic” (published 1985).  This landmark textbook was updated with Brent Owens and published in its 3rd edition as Blatt, Tracy and Owens in 2006. It is still in common use today.

Those who knew Bob well, or who have subscribed to this listserv for some time, will be aware of both the depth and the breadth of his knowledge.  He was a font of information, a walking encyclopedia of mineralogy, petrology, optical and electron microscopy, sample preparation, wine, french cuisine, European and American political history, fishing, barbecue (amongst many other topics).  Bob liked nothing more than using this information to help people, and students in particular, generally espousing his wisdom with a carefully pointed wit.  His generosity in terms of sharing his time, knowledge, ideas, data and opinion are difficult to equal.

He will be greatly missed,

Mark Caddick & Nancy Ross,

Department of Geosciences, Virginia Tech
########################################################################

Probeman

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Re: History of EPMA
« Reply #26 on: January 26, 2019, 12:34:05 PM »
I think it's Peter Duncumb's birthday today:

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Probeman

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Re: History of EPMA
« Reply #27 on: March 15, 2021, 10:01:48 AM »
Here's a photo I found recently that shows the ARL SEMQ that UC Berkeley purchased in the late 1970s at a trade show. Yes, the actual instrument which they got a discount on because it was a "prototype".



My advice: never buy anything with a low serial number!

After the instrument had been destroyed by an errant airlock exchange valve decapitating the stage and imploding the diffusion pump thus spraying Fomblin fluid all over the electron column, light optics and WDS spectrometers, which then polymerized forming a hard plastic coating on everything, the electronics tech (George Engeman) and mechanical tech  (yours truly) were called in to disassemble, clean (in boiling methylene chloride!), and rebuild the instrument. Here is a photo of myself testing the new instrument still running on the trusty PDP-11 with 64K RAM:



The PDP-11 and the (removable) 10 MB disk packs are seen in the lower left.

It was then we realized that we needed a better computer so here is the same mechanical technician after writing new software for the then recently released IBM AT PC with 10 times the memory (640K)!



Remember "640K ought to be enough for anybody" sometimes attributed to Bill Gates.  The IBM PC can be seen behind the technician.

Also note the monocular light optics which was a modification, because the original binocular optics produced images of a slightly different sizes, which caused most users "wanging" headaches because the brain was trying to see them as the same size FOV.
« Last Edit: March 15, 2021, 12:38:03 PM by Probeman »
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jon_wade

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Re: History of EPMA
« Reply #28 on: March 15, 2021, 03:34:16 PM »
cracking pictures - that ARL looks like how I imagined the future! and thats no Technician!

I don't know if anyone has pics, but the old Camebax we had in Bristol was held together by vacuum alone (there was a bet that someone, no names, might knock the 'power off' and the whole column collapse around them with comedy effect). 

I was quite fond of this old banger until I found  an old replacement green CRT screen in a box behind it. The screen (the imaging screen)  had been made in a factory that catastrophically blew up whilst I was working there. My mate had got me the job when I left school and, luckily for me, I was a bit hungover one morning and had sneaked off to the canteen for a bacon roll rather than checking on a vapour deposition process.  What my chum didn't tell me was that he had been blown up two years previously checking the same process.....  Anyway, thats why, if you needed a replacement CRT screen for a Camebax you couldn't get one for love nor money - I was hungover.

Probeman

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Re: History of EPMA
« Reply #29 on: March 16, 2021, 08:58:41 AM »
Our Cameca SX50 came with special Sony "overlay" monitors that were originally built for the film industry.  They were used to display number of feet of film remaining, etc.   Cameca utilized them for displaying the WDS crystals and mag info.

I was happy to replace these old vacuum tube monitors with flat screens (using a homemade video overlay circuit), but at least the old Sony monitors never blew up on us!

https://probesoftware.com/smf/index.php?topic=173.msg752#msg752

Login to see the attachments which include our video display modifications in order to utilize flat screen monitors for the overlay video.
« Last Edit: March 16, 2021, 09:05:59 AM by Probeman »
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