Volume 1: Student Life Chapter 214 Experimental Data
The experiment officially began at 10 o'clock in the morning.
The experiment will be conducted in three steps.
They are short-circuit test and open-circuit test of the generator, and the short-circuit current and open-circuit voltage will be measured .
The dummy load experiment from the generator to the transmission line to the dummy load resistor will measure the voltage across the generator and the dummy load resistor.
The beam test from the generator to the transmission line and then to the diode joint test will measure the typical voltage and current of the diode.
The measurement of these data will be carried out through specific parameter measurement devices.
The experiment was carried out quickly and the data feedback was timely.
With the switch closed, the final step of the beam emission experiment begins.
The fully charged magnetic pulse generator begins to discharge through the double-forming line-pair diode to form a strong pulsed particle beam.
At this time, Chen Zhou finally knew that the diode used in this experiment was called anode rod pinch focusing diode.
This is a coaxial diode developed from the conical anode reflector focusing structure used in early flash X-ray machines.
The structure of the anode stem pinch focus diode uses a thin annular cathode surrounding a small diameter anode stem, and this anode stem gradually tapers and extends a distance beyond the cathode plane.
In this diode , the electrons emitted from the radial cathode are pinched back under the action of the beam's magnetic field, focused toward the downstream of the cone, and finally bombard the anode tip made of heavy metal, thereby producing bremsstrahlung X-rays.
Then, these X-rays are emitted from the anode tip which is sharpened into a needle shape, and can form a point source-like X-ray.
The advantage of this diode is that the focal spot formed is small, stable and has a simple structure.
Chen Zhou estimated that this was also the reason why President Yang and his team chose the anode rod pinch focusing diode.
Considering what Peng Jia just said, there will probably be many more experiments with other diodes in the future.
Chen Zhou carefully observed the various measurement data fed back.
His greatest contribution to this research group is probably to discover the greatest value in these data.
Only by analyzing the data can the experiment be optimized.
How to obtain a strong beam with a small focus, stable shape and position, and how to obtain an electron beam or ion beam with a large area and good uniformity all need to be discovered from experimental data.
In particular, the research on strong pinch diodes, how to move towards high voltage > 10MV, small focus < 1mm, high brightness of 1000R irradiation at 1m, as well as multi-pulse and multi-amplitude, are also included in the experimental data.
The experiment ended quickly.
After the experimental data was sorted out, Dean Yang announced the end of the experiment and arranged preparations for the next experiment.
Chen Zhou felt a little emotional. This experiment was indeed quite laborious and time-consuming.
"Chen Zhou, how many days will it take to process the experimental data?" Dean Yang turned to look at Chen Zhou and asked.
Chen Zhou hesitated for a moment, then said, "Two days."
He is not in a hurry to start the math subject again now, so he can devote all his time to this subject.
After hearing what Chen Zhou said, Lin Xiaoen and the others looked at each other, wondering if this kid had never dealt with experimental data before. It’s only been two days?
Originally, they were against Dean Yang giving the task of data processing entirely to an undergraduate student, but Dean Yang guaranteed Chen Zhou's support.
They couldn't say anything more.
However, Chen Zhou's boast made them feel a little uneasy.
However, Dean Yang said, "Okay, send the data results to me and Peng Jia in two days."
Chen Zhou nodded.
Dean Yang arranged Yang Yiyi to work in the laboratory with Peng Jia.
Unlike Chen Zhou, Yang Yiyi is a pure physics student, and Dean Yang has higher expectations of her.
After briefly arranging the laboratory work, Dean Yang took Chen Zhou out of the laboratory.
After Chen Zhou left, Lin Xiaoen finally said, "Senior, do you think this guy is reliable?"
Peng Jia naturally knew that Lin Xiaoen was talking about Chen Zhou. She glanced at Lin Xiaoen and said, "Don't let your imagination run wild. He is a student in the Department of Mathematics, and since Dean Yang thinks highly of him, he must have some outstanding qualities."
Lin Xiaoen still said: "But, this is an experiment we have worked hard to prepare for for such a long time. If it is delayed..."
"No." Yang Yiyi interrupted Lin Xiaoen and said slowly, "If we only talk about data processing, I don't think any of us can compare to him. He is more than just a student in the Department of Mathematics."
Lin Xiaoen looked at Yang Yiyi doubtfully: "Do you know him well?"
Peng Jia also looked at Yang Yiyi with interest.
Yang Yiyi smiled softly: "He knows a lot about it, right? He just solved the difficult problem of the hail conjecture recently."
"What? Hail hypothesis?!" Lin Xiaoen and Peng Jia blurted out at the same time.
Although they stayed in the laboratory for a long time, it didn't mean that they didn't know what the hail conjecture was.
"How is this possible? Isn't he just a sophomore?" Lin Xiaoen suspected that he had heard it wrong.
At this time, most of the researchers in the laboratory noticed the movement here.
The news that this little girl said was a bit too shocking.
Yang Yiyi said calmly: "Does being a sophomore have anything to do with solving the hail conjecture?"
"Uh..." Lin Xiaoen was speechless.
But after get off work today, he will definitely check the news on this matter.
If it is true, then he has no objection to Chen Zhou handling the data.
Are you kidding? A professional mathematician can’t even handle some experimental data?
Chen Zhou, who was already on his way back to Yan University, had no idea what was happening in the laboratory.
Even if he knew, he probably wouldn't explain it.
Once the experimental data is processed and the results are presented, the doubts will naturally disappear.
In fact, Yang Yiyi didn't intend to say much, but this senior Lin Xiaoen, who seemed to be so enthusiastic, was whispering about her happiness behind her back. How could that be acceptable?
After returning to Yanda, Chen Zhou had a simple lunch, went back to the dormitory, and went to the library with his computer.
It was said to take two days, but according to his own actual estimate, it was probably about a day and a half.
"The current development process in the anode rod pinch focusing diode, let me think about it... Hmm..."
[At low voltage, the electrons move radially, which is space charge limited flow. At higher voltage, weak pinching begins, and the electrons begin to approach the anode and graze along the surface. ]
[At higher voltages, strong pinching occurs, forming a self-magnetic insulation flow. With the help of ions generated by the anode, electrons flow to the tip of the anode rod. In the magnetic confinement area, electron flow equipotential lines are formed, and most of the current reaches the tip of the anode rod. ]
After writing this process down on the draft paper, Chen Zhou looked at it again, tapped the draft paper a few times out of habit, and continued writing:
[In non-cylindrical geometry, under non-relativistic space charge confinement, the space charge confinement flow formula given by the Langmuir and Blodgett formulas can be inferred that when the diode current Rc/Ra is a constant, the current I is inversely proportional to Ra and directly proportional to l...]
[That is, the critical current for pinching Ic = α·8.5·(γ02-1)^(1/2)/ln(Rc/Ra), which has nothing to do with the length and only depends on the value of the ratio of the cathode radius to the anode rod radius Rc/Ra...]
[…When there are ions, α increases from α=1.6 when Rc/Ra≈1~2 to α=3 when Rc/Ra=16. γ0 is the relativistic factor, and γ0=1 ＋eV0/mec2. ]
【Therefore, the dose generated at a distance of 1m from the diode can be expressed as D(t)=7×10^(-4) I(t)V(t)^1.11rad.s^(-1). 】
According to the current development process in the anode rod pinch focusing diode, Chen Zhou first sorted out the formulas that would be used.
For him, this is a comfortable way to process data.
