Granville-Phillips/MKS Announces a novel Wide Range Cold Cathode Ionization Vacuum Gauge

It was an interesting day when I first heard about MKS’s plans to release a new wide range cold cathode gauge. I though to myself, “does the world need another 10-2 torr Cold Cathode Ionization Gauge?” Well, if that is what you are asking yourself, too then take a closer look. This transducer provides a wide measurement range of 10-7 torr to Atmosphere, eliminating the need for multiple gauges.

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Revolutionary new CCIG has a range for High Vacuum to Atmosphere. Image courtesy of MKS Instruments, Inc

The Series 523 uses two different types of discharges. The first is the normal pressure dependent discharge found in every CCIG which covers the range from 1 × 10-7 to 1 × 10-2 torr. The second range between 1 × 10-2 torr up to 10 torr is derived from a glow discharge measurements cause by the breakdown of the gas by the electric field.  Above 10 torr, the pressure is measured by the arc discharge current.  The published accuracy of the gauge is +/-50% over the range of the gauge.

The cost is contained by the elimination of expensive ceramic-to-metal seals. The 304 SST electrode structures inside the gauge are unique and made possible by using injection molding technology to build the sensor. The electrodes are held in place by the polymer that forms the vacuum envelope and the electrical feed through materials. The polymer, Polypropylene, was selected for low outgassing rate, mechanical and temperature stability and electrical properties.

The target market for this gauge is that set of processes that do not heavily rely on accuracy but just need basic vacuum level information. For applications that require higher degrees of accuracy, MKS provides a vast selection of vacuum measuring solutions.

Understanding Modern Vacuum Technology describes Cold Cathode Ionization Gauge technology as well as all the other pressure technology used in science and industry today. UMVT  is available through

You can read about the MKS 523 wide range CCIG on the MKS website.

LIGO Vacuum Systems and Gravitational Waves

LIGO is an acronym for Laser Interferometer Gravitational-wave Observatory. The purpose of LIGO is to detect gravitational waves. Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity. Einstein’s mathematics showed that massive accelerating objects (such as neutron stars or black holes orbiting each other) would disrupt space-time in such a way that ‘waves’ of distorted space would radiate from the source. In the semiconductor industry, I am concerned with a final product on a microscopic, nanometer scale on microprocessor chips. LIGO is at the other far end of the curve dealing with massive object colliding in space.

The problem is that detecting gravitational waves is an extremely difficult task. The waves will cause distortions in space on earth that are shorter than the dimension of an atom’s nucleus. In fact the distortions are on the order of 1/10,000th of the diameter of an atomic nucleus. The detector has to be super sensitive and in a very quiet location. Vacuum technology plays a key role in this experiment.


LIGO Livingston. Courtesy Caltech/MIT/LIGO Laboratory

LIGO consists of two interferometers, each with two 4 km (2.5 mile) long arms arranged in the shape of an “L”. Each chamber encloses 10,000 cubic meters of volume. One interferometer is located in Hanford, Washington and the other in Livingston, Louisiana. The reason for two is that the earth is a very active place with lots of human hustle and bustle. There are earth quakes and storms. So if the detectors both capture the same signal, then that is strong evidence that the signal is a gravitational wave.

When gravitational waves pass through the system, the distance between the end mirrors and the beam splitter lengthen in one arm and at the same time shorten in the other arm in such a way that the light waves from the two arms go in and out of phase with each other. When the light waves are in phase with each other, they add together constructively and produce a bright beam that illuminates the detectors. When they are out of phase, they cancel each other out and there is no signal. Thus, the gravitational waves from a major cosmic event, like the merger of two black holes, will cause the signal to flicker, as seen here

Gravitational waves sent out from a pair of colliding black holes have been converted to sound waves, as heard in this animation. On September 14, 2015, LIGO observed gravitational waves from the merger of two black holes, each about 30 times the mass of our sun. The incredibly powerful event, which released 50 times more energy than all the stars in the observable universe, lasted only fractions of a second.

In the first two runs of the animation, the sound-wave frequencies exactly match the frequencies of the gravitational waves. The second two runs of the animation play the sounds again at higher frequencies that better fit the human hearing range. The animation ends by playing the original frequencies again twice.

As the black holes spiral closer and closer in together, the frequency of the gravitational waves increases. Scientists call these sounds “chirps,” because some events that generate gravitation waves would sound like a bird’s chirp.

Audio Credit: Caltech/MIT/LIGO Lab

The lasers are operated in a vacuum level on the order of 10-9 torr. This ensures that there are no air currents causing distortion of the laser beams either through transmission of sound or thermal energy. Also it lessens the chance of particle movement in the vacuum system.


Spiral welding a section of a vacuum tube. Courtesy Caltech/MIT/LIGO Laboratory

LIGO’s vacuum tubes were constructed of spiral-welded 3 mm thick 304L stainless steel. With its relatively low carbon content, 304L steel is resistant to corrosion, especially at the critical welded seams. The 1.2 m diameter beam tubes were created in 19 to 20 m-long segments, rolled into a tube with a continuous spiral weld. To prevent collapse, LIGO’s tubes are supported with stiffener rings that provide a significant layer of resistance to buckling under the extreme pressure of the atmosphere. The tubes must withstand these stresses for at least 20 years.

Evacuating the chambers took 40 days of constant pumping to evacuate them to their optimal operating pressure. In that time, turbomolecular pumps removed the bulk of the air in the tubes while the tubes themselves were heated to 150-170 degrees C for 30 days to drive out residual gases.

The gases that remain in the system are primarily H2 and water vapor. There are liquid nitrogen cryogenic panels in place to capture the stray water molecule and ion pumps to capture H2 gas. There is so much more technology involved in the LIGO detectors. I encourage you to visit the LIGO website. Although LIGO depends on extreme vacuum engineering, the vacuum technologies involved are explained in Understanding Modern Vacuum Technology.

NOTE: On June 1st, 2017, LIGO made their third detection of a gravitational wave event from the collapse of 32 solar mass black hole and a 19 solar mass black hole forming one large black hole of 49 solar masses. The means that two solar masses of material were transformed into energy by the collision.

Training the Next Generation of Vacuum Technologists

I had the opportunity to talk with Del Smith of Normandale Community College in Bloomington, Minnesota last fall at the American Vacuum Society Symposium in Nashville, Tennessee. Del has put together a phenomenal set of accredited classes specifically to teach vacuum technology and thin film technology with the purpose of graduating qualified technicians.

In this video, Del presents the concept of vacuum technology to laypeople and discussed the importance of training qualified technicians. He points out that unlike mechanical, electrical or medical technicians, vacuum technicians are a relatively small group of individuals but are in high demand.

It is well worth watching this video as Del explains the importance that industry is placing on having trained individuals who understand in detail vacuum technology beyond just being able operate the equipment from recipes without understanding.

From the YouTube post:
“Published on Nov 9, 2016 From TVs to potato chip bags, “thin film” is used in myriad ways. Normandale Community College is helping to make it possible for you to use all of your current technology. It is the only community college in the country to offer an associate degree in vacuum and thin-film technology. Every electronic device uses thin film in some way and NCC is focused on the thin-film used in computer chips and computer hard drives. Del Smith is a graduate of the University of Minnesota, and has worked for high tech companies in the Twin Cities area his entire career. Del spent thirty years at Honey-well Aerospace, where he was the lead engineer in two different areas; the Thin Film Facility and the Vacuum Laboratory. Del was a member of the team that established the Vacuum and Thin Film program at NCC in the mid 1990s, and taught part time for a few years. The program was started at the request of several local companies who recognized the need for more educated technicians as the equipment they were using became more complex. Today, due to a three year $800,000 grant from the National Science Foundation, Del’s class reaches students not only in Bloomington, but as far away as Ireland through “telepresence” instruction. Join us to learn more about this technology and the ways our lives depend on it.”

I admire Del for the well thought out program and equipment he put together and his desire to to give back to the vacuum industry.


AVS 64 in Tampa


Preparations for the program of AVS 65 International Symposium and Exhibition are well underway. The deadline for the submission of was the 1 May, 2017. That means that those of us who are on the Program Committee of the Vacuum Technology Division are reading through the abstracts and putting together the program.

I have just been through the 57 abstracts for the VTD program and I am impressed. We will be getting briefed on some cutting edge technologies. There is a new paradigm in pressure technology discussed. NIST is moving over from mercury manometers to photonic based pressure standards.

Tri Alpha Energy will be giving a talk on the progress of their latest fusion reactor. They have some very stringent vacuum requirements and are using chemisorption surfaces to pump H2 along with cryogenic surfaces.

There will be several discussions about vacuum generation in high energy physics experiments in Japan, the UK, Germany and the US.

Paul Arnold of MKS/Granville-Phillips will give an invited talk as part of the AVS History Committee endeavor to preserve our technical heritage. He will discuss the Electro-Ion pump developed in the 1960s. This was a complex UHV pump that combined cutting edge technologies in one package; a titanium sublimation pump with a triode pump.

There will be discussion about handling EUV exposure systems, vacuum systems to improve storage batteries, process development for new lighting technologies and much, much more.





First blog post: Confessions of a long time blogger

It has to start somewhere. I am not new to blogging. I have been blogging for over 10 years. My current photography blog has been in publication for 9 years and my wife and I ran a wine blog for a couple of year before that. Blogging is getting to be a little old school, but still, it is an effective method of communication about a topic.

I bring all this up because one is tempted to exclaim from the mountain tops, “This is my blog! I am going to say really important things and it is going to__” and then lay down a bunch of ideas of what the blog will be only to have it evolve into something else. I must truly confess, I have ideas for the blog, but honestly, after seeing so many blogs come and go, I think that I will just sit back and relax today and not worry about what it will be tomorrow.

So about this Understanding Modern Vacuum Technology book. I had been toying with the idea of writing a manuscript of the vacuum principles that I use frequently. I have lots of books and references, but every time I want to find that handy-Jim-dandy reference that solved that problem five years ago, I would have to figure out where I found it before.

The next problem I faced, after becoming a corporate vacuum guru, was that folks would walk into my office and ask me questions vacuum technology. “Now where was that handy-Jim-dandy reference? Oh, it is in Dushman’s† second book. Oh Lord, I can’t send Pete away with that book, how will he separate out the old that applies to the new?”

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Dushman, 1949, Scientific Foundations of Vacuum Technique, John Wiley & Sons, Inc.

So I decided to write my own book. Feeling good about that decision, I put it off for about six years. You don’t want to go rushing into these things, now do you? Then one fine day, or maybe it was during a nor’easter‡ and I was getting cabin fever, I decided that the I just needed to get started on the book and get it done. How long could it take?

I bumped into my old friend and mentor, Paul Arnold from Granville-Phillips. Still feeling a little wobbly on my pins about writing a text book, I figured that if I actually announced to Paul that I was writing a book, then that would be like a promise or a commitment to follow through and get it done. “Paul, I’ve decided to write a vacuum technology book.”

“Well, then,” Paul interjected, “that will keep you busy.”

He was right, but I was thoroughly committed. Sometimes when you are “stuck in a maybe”, you just have to make a decision. I now had my “winter project” to get me through the next season of nor’easters.

So that was the genesis of Understanding Modern Vacuum Technology. I has burned up 800 to 1000 hours of spare time. (Paul was right.)

Oddly enough, the little book has been doing okay. I am surprised at who is reading it. I expected engineers types, but there has been feedback from executives and sales folks in the industry, too.  I had a Ph.D student stop me to tell me that it helped her with a problem in her thesis.

And all that makes me happy because I know that finding that handy-Jim-dandy reference can be difficult enough for a died-in-the-wool “Torr-head” like me. At least I can make it easier for others.

So this is the start of this blog. My next posts will be of more significant content.

Saul Dushman: vacuum technology pioneer and former Assistant Director, Research Laboratory, General Electric Company Schenectady, NY

nor’easter‡: A nor’easter (also northeaster) is a macro-scale cyclone. The name derives from the direction of the strongest winds—as an offshore air mass rotates counterclockwise, winds tend to blow northeast-to-southwest over the region covered by the northwest quadrant of the cyclone.