I had an interview in a auditorium before ten veteran trainers, ten sy stems engineers, three managers, and a emeritus VP of Engineering, to get t hat X=Ray job. The interview was competitive, and I was the last of five to go. Anyone working in the division could come, watch my presentation, a nd ask questions. Quite a few did.
I did a ten minute lesson on a topic of my choice, and then was grilled on my knowledge of teaching techniques, physics, detectors, noise, servo syst ems, for forty five more minutes.
Then there was the second interview, setting at a CT with the covers pulled and manuals out. I was the only one of the perspective employees who could explain how a resolver worked when presented with one. And I assure you most CTs have a massive resolver imbedded in the rotor.
I was offered the job over several experienced senior engineers because I knew the physics, and because I lugged in a one hundred pound switching la ser power supply and test equipment, on a cart, and used them in my demo le sson.
I resent the implication that I do not know my X-ray physics. I was part of a seven person teaching team that trained thirty FSEs on the system, fr om the ground up, on a sixty day course. Not only did we do CT, but we sat in on ultrasound, other clinical X-ray systems, and comparative courses on other manufacturer's hardware, including inspection systems. I had sixteen machines of different vintage to maintain in one teaching hall alone. At any time I could be sent out in the field in an emergency, on an actual med ical system.
Funny thing about clinical X-ray, competitors do maintain each others sys tems in parts of the world where the competitor has a presence and the prin cipal manufacturer did not. So you could say I faced outside review of my teaching. Plus I sat all the exams on the system three times.
Not to mention diagnosis was readying around 4000 lines of commented comm ands going to and from the rotor on CANBUS per rotation. So I have a damn g ood idea of what the PSU and detector was doing. The detector returned data at 5.6 gigabytes per second over an array of free space laser diodes into a RAID array. The detector team came in and gave us lectures, so we could make new lesson s for the students. The local R and D team used the training machines for t heir tests of new hardware, and ANY part I needed was shipped in over night or supplied from the warehouse next door within 24 hours. This let us put faults in any part of the system or let the students blow a board.
So you geniuses can read up on Dual Spectrum X-Ray, Helical Scan, forth and sixth gen CT, Bremsstrahlung and Characteristic Radiation, K line, MaS, detector adsorption profiles, Edge Filters, Filter Wheels, and independent setting of tube current irrespective of tube voltage, because I lived it f or twelve hour days, six days a week. Because the Junior trainer was the on e who had to come in on Saturdays and oversee the students who were behind, and test every machine in the hall.
In classical tube terms, the tube was actually a Pentode, Two cathodes, a f ocus cup, a deflection electrode, and an anode.
Because five years later, I can still remember how to uncrate, position, an d align the damn machine in my sleep, and diagram the phantom and its adsor ption curves. I know about the anode, because I can still quote the HU numb ers. Not a one of you has mentioned tube conditioning, and why the anode is heated before scans to stabilize its spectrum across the spot and to clean up the vacuum before a PT run.
I had to profile all the aluminum in the path to align it, I have a damn fi ne idea of what x-ray lenses can and can not do.
I used to love SED, but I get real tired of people shouting off on systems they do not have a clue on.
Steve