This experiment is only a preliminary experiment, even if the experimental process is known, there is no loss, so the secrecy is much worse, so his mentor can take him there, otherwise he would not even have the qualifications to enter the laboratory.

After explaining the meaning of some formulas, it was already half past one, and the experiment would start in the afternoon.

The name of this experiment is called the experimental method of neutron-nuclear interaction cross-section, and the method used is the transmission method, which calculates the reaction cross-section of neutron-nuclear interaction by directly measuring the number of transmitted particles after the incident particles pass through a target of a certain thickness.

The principle of the method is that a beam of neutrons with an intensity of 0I hits a sample with a thickness of t, and the number of nuclei per unit volume of the sample is N. Because of the nuclear reaction and elastic scattering of neutrons and samples, the neutrons are attenuated in the beam direction, and the degree of attenuation is directly related to the cross-section of the neutrons.

With the thickness of the sample and the number of nuclei per unit volume in the sample, the neutron beam is measured with a neutron detector in both the presence and absence of a sample to obtain the transmittance, which can be obtained for the full cross-section.

This experiment requires certain experimental conditions, in which the size of the neutron source, the sample and the detector are all required, and the typical geometry of the full section is measured by the total transmission method. In terms of neutron sources, the strength of the neutron beam is required to be stable and to have an appropriate energy range of incident neutrons.

The original is measured by a low-energy accelerator, but the accelerator state is relatively unstable, and the energy of the neutron needs to be constantly adjusted, but with the development of other accelerators, the white light source has the best application value, and the selection of the size and position of the sample makes the detector unable to directly detect the neutron that has not passed through the sample, that is, the "good geometry" condition.

There are a large number of factors in the actual experimental process, which affect the accuracy of the results, so some major influencing factors need to be corrected appropriately.

For most experiments, there is an environmental background, and there are more or less neutrons around the detector that are not from the neutron beam, which will seriously affect the accuracy of neutrons, so it is very important to reduce the influence of environmental background.

At present, this kind of experiment has been relatively mature, so the result is not important, as a big man in the neutron field, Chen Dezhi is not worried, this time is not successful, there will be a next time, as long as the experiment is successful, do not care about the process.

After following the supervisor to the laboratory, I found that many people had come to the laboratory, and they were all graduate students, who could also be said to be his senior brothers.

Everyone saw Chen Dezhi come to the laboratory and greeted them one after another, as for Shang Yiyun, because they met for the first time, they didn't know anyone, so they just said hello, my name is ***.

Faced with this situation, Shang Yiyun responded with a smile, and then reported his name.

After some pleasantries, the experiment officially began, and everyone restrained their smiles and expressions were very serious.

In the process of experimentation, everyone does not dare to be careless, physical experiments are very strict, and if there is a slight mistake in the experimental process, all efforts will be lost, so everyone's heart is in a tense state.

The experiment was completed step by step, and it took half an hour to work hard, and the experiment was completed significantly, this experiment, someone had tried it before, but this time it was just on the basis of the predecessors, and this kind of experiment was just to get some data.

"Yi Yun, have you gained anything from this experiment?"

Hearing the words of the mentor, Shang Yiyun expressed his experience.

After hearing this, Chen Dezhi was also more satisfied, he let Shang Yiyun observe this time, that is, let the other party enter the real world of physics, experiments are an indispensable part of learning physics, and many major discoveries in physics need to be verified by experiments.

After the experiment, Chen Dezhi took Shang Yiyun out of the laboratory, and the data results of the experiment were sorted out by someone, so there was no need to participate in the troublesome things behind.

Looking at the laboratory in front of him, Shang Yiyun's heart burned with pride, he believed that the time was not far from his qualification to enter this laboratory, as long as his physics knowledge level could reach 60% of the master's level and pass the test of Chen Dezhi, he could enter it and do it himself.

After walking out of the laboratory, he said goodbye to his tutor, and while there was still some time this afternoon, he was going to go to Huaguo Normal University once, and while Chen Feiyun had no class this afternoon, he was ready to discuss with the other party where to go on National Day.

There are many cities that can be traveled to in the country, but the National Day holiday is only seven days, so you need to choose well, and where you can go in the end requires the consent of both people.

Some cities in Dongshan Province do not need to be considered, and the main thing now is whether to go to the south or just to the north, which is a question.

The characteristics of the south and the north are different, most of the north is a cultural landscape, while the south is mostly a natural landscape, the type is different, and the feeling is not the same.

On the way, Shang Yiyun called Chen Feiyun and asked the other party to come out, he was going to wait at the door, after the last time he entered, he was not ready to enter the campus again.

When I came to the gate of Huaguo Normal University, I waited for nearly ten minutes before I saw the other party.

"Fei Yun, I came this time, mainly to discuss with you where to go on the National Day, the seven-day National Day holiday, I am going to play with you for a few days, I am not ready to go home, what are you going to do?" Shang Yiyun didn't talk nonsense, and directly stated his purpose.

Hearing Shang Yiyun ask where she wanted to go, Chen Feiyun pondered for a while and spoke.

"I haven't been to the south yet, during the National Day holiday, let's go to the magic capital for a few days, is it okay?"

Regarding Chen Feiyun's proposal, Shang Yiyun thought about it for a while and agreed, although he had been there in the previous life, but having a girlfriend to accompany him in this life is believed to be a different journey.

After finishing business, I bought an ice cream for each other and walked around the school, enjoying the feeling of companionship.

No matter how long the journey was, it didn't take long to come to the side gate of the school, Shang Yiyun knew that it was time to part, and watched the other party's figure disappear in front of his eyes, so he reluctantly left this place and prepared to return to Kyoto University.

Today is Wednesday, there are still four days left before the National Day, and after spending the last four days at school, he can take Chen Feiyun to the magic capital, go to see the Oriental Pearl TV Tower together, and go to Disneyland together......

In the magic capital, there are many places to play, and the places that I have been to in the last life have only a small part, and the last time I came was during the professional investigation, and the itinerary has been arranged.