James Stephenson

My First Real Full-time Job

My job interview at Argonne was February 15, 1961. I arrived from Los Angeles the day before. The overnight temperature in Chicago on the morning of February 15th was minus twenty-five degrees F.

I was a very cold Californian as I made my way through the snow from building to building for my appointments. The last interview was with Dr. John Martin, head of the RF Group of the ZGS project. He was in a Quonset hut at the western edge of Argonne. It was a bleak sight in the snowy afternoon gloom of that cold winter day. I had no idea what a "ZGS" was and I had no experience in RF circuits but the interview gave way to a job offer from Dr. Martin. Back at Hughes I gave my boss, Joe Stover, six weeks notice. He tried to talk me out of leaving, but he didn't know that Shirley Smith was my real reason for going back.

My drive to Illinois in mid April began with a weekend camping trip with the Youth Group from the Congregational church. There were about six of us who slept in the desert with raccoons watching from the trees overhead. When the weekend was over we said our sad goodbyes, and they headed back west and I east. The trek back home was long and lonely. I was hoping to stop at Missouri Central College in Fayette to see Shirley and break up the boredom, but she wasn’t answering my letters. I couldn’t even find a hitch-hiker to talk to along the way.

I was back in Lockport by April 20th and moved back into my old room at 605 Twelfth. Following a week of relaxing, I began work at Argonne on Monday, May 1st. I was almost 25. It was an immediate wake-up call to responsibility. Dr. Martin delegated! He clearly felt that the training that produced two degrees in Electrical Engineering should count for something. Soon I was in charge of at least four very different projects: (1) the Master Oscillator, (2) the Cavity Bias System, (3) the B-dot Coil, and (4) the System Status and Interlock system. I also worked on some high-energy-physics projects with physicist Stuart Markowicz.

A feature of employment at Argonne was that each engineer supervised a number of technicians, generally one or more technicians per project. Working with me full time were Carl Wegner, Tony Donaldson, Leon Bartelson and Norm Wilson. When I arrived Carl Wegner had already been on the Master Oscillator project for several years. His attitude was, "OK, you’re the guy. Tell me something worthwhile to do."

Here is a rundown of the four projects. The Master Oscillator system taught me a lot about RF circuits and servo feedback systems. The master oscillator drove the very-high-voltage RF cavity that provided the kick to each proton as it came around the ring. As the protons sped up, the frequency had to increase to keep everything in synch. This meant that the master oscillator frequency went from 4 to 14 MHz during the one second it took to accelerate the protons to nearly the speed of light. The precision had to be plus or minus one part in ten thousand. The oscillator was immersed in a constant-temperature oil bath. A feedback system kept the oil temperature constant. My graduate course in servomechanisms paid off. Regarding RF circuits, I learned that capacitance and inductance are not just discrete components but entities that are everywhere. Inductance, as well as resistance, exists in all conductors, and capacitance exists between any two circuit components as well as from component to chassis (ground). At RF frequencies, these spurious parameters have to be reckoned with.

The Cavity Bias project was all about precise control of high current. The RF cavity was basically a tuned circuit. You changed the resonant frequency by varying a bias current that saturated the core material and changed the inductance of the tuned circuit. The current required to do this was hundreds of amperes, and two hundred transistors were wired in parallel to provide the necessary precision control. This was a fairly aggressive use of transistors, and great care was taken to protect them. They were mounted on a water cooled manifold and each had a little light that would shine if the transistor shorted out. It was a dark moment the day I checked the system and found all 200 little lights shining brightly. Dr. Martin was not amused. It was as if I was put on earth to protect the precious little transistors, and I had failed.

Then there was the B-dot coil. Everyone knows that a change in a magnetic field enclosed by a loop of wire that has a break in it will produce a voltage across the break. Such voltage is directly proportional to the rate of change of the magnetic field. The voltage, v, is equal to: k x dB/dt, where k is a constant, B is the magnetic field, and t is time. The time derivative of magnetic field, dB/dt, is called "B dot." In the ZGS it is necessary to know the magnitude of the magnetic field that is bending the protons in a circle as they are being accelerated. To come up with a representation of this field, "B," all you have to do is "integrate" the dB/dt signal.

The System Status and Interlock system was basically a relay rack full of relays and indicators.

I have some specific memories about Argonne. Shirley and I set our wedding date for June 30, 1963. We planned a honeymoon in the Bahamas and I asked Dr. Martin for three weeks off. I was pretty upset when he proposed one week instead. I think he felt that my projects were behind schedule, and they probably were. To his credit, he suggested that I take it up with Lee Teng who was head of the ZGS project. (I'm sure I reflected on my experience five years earlier when Mr. Berner, head of Men's Residence H-1 at Purdue, suggested I go see his boss, Jack Smalley.) Dr. Teng proposed a two-week compromise, which actually wound up being plenty of honeymoon.

Shortly after returning to work, I was standing in the lab area. I shook my left hand for some reason, and my wedding ring flew off. We couldn't find it anywhere, but there was a little hole in the floor under a workbench. Sure enough, I found my ring in the basement. I had the ring immediately resized, and it hasn’t been off my finger since that day. It’s too small to come back over the knuckle.

Several months later I was walking across that same basement area around lunch time and happened to pass an African-American gentleman walking the other way. He said, "Did you hear? Kennedy’s been shot." That’s where I was when I heard the news.

Around 1965 I took a night class in FORTRAN. That was a life-changing event. I loved it and still get a warm feeling when I think about it. Ed Barsotti and I wrote a circuit analyzing program we called NETWORK. It featured user-friendly input and graphical output, both in frequency domain and time domain. I used NETWORK to analyze the stop filters on the Loche organ. I began spending lunch hours in the basement of Building 365 where I could have this awesome computer to myself for an hour. My dream of having my own company was definitely stoked, because companies, not people, had the resources to have a computer in those days.

Well, eventually all the systems worked, and in 1968 the ZGS became operational. From this point on the ZGS ran around the clock, and a call in the middle of the night to come and look into a problem happened every now and then. Our technicians were generally immune from such calls since they had to be paid to come in. I began to long for the good old “design” days. The action was in "Operations" and in high energy physics, and I wasn’t excited about either one of these.

But, there was a lot of good stuff just over the horizon. I was 32.