Reborn and become a Great Scientist

Chapter 346 85 Hydrogen Fusion of hydrogen to produce deuterium

Eddington was very interested in the experiment that Chen Muwu announced in the Times that he was about to do it, and he couldn't wait to do it for him.

He also brought out his age and past experiences in an attempt to persuade Chen Muwu to agree to the matter.

There are so many flaws in this matter that Chen Muwu doesn't know where to start.

After Eddington graduated with a master's degree from Trinity College in 1905, he entered the Cavendish Laboratory and conducted experiments with Old Thomson.

Perhaps because of his weak hands-on ability or insufficient experimental talent, Eddington worked at the Cavendish Laboratory not long before he left Cambridge University in the same year after graduation and entered the Royal Observatory in Greenwich, London, where he began to work. Engaged in the research of astronomy, using his superb mathematical calculation ability to calculate related problems.

After all calculations, Eddington could only work in the Cavendish Laboratory for more than a few months. Now he said that he would help Chen Muwu, which made Acting Director Chen unable to let go.

Similar to Eddington's experience, it was Professor Bohr in Copenhagen.

Bohr received his PhD from the University of Copenhagen in 1911 with a paper on the theory of electrons in metals. Then he took a boat across the North Sea and traveled across the ocean to England.

Bohr also almost completely followed Eddington's steps. He also showed that he entered the Cavendish Laboratory, joined the old Thomson's disciples, and conducted experiments for several months.

Then he left the University of Cambridge and transferred to the Victoria University of Manchester, where he became the only theoretical researcher under Rutherford, providing various theoretical support for the latter's experiments and starting his own theoretical physics research.

Later, Bohr returned to China, won the Nobel Prize in Physics, founded the Institute of Theoretical Physics at the University of Copenhagen, taught and educated people, and eventually became the head of the Copenhagen School and a great master in physics.

In Bohr's entire physics career, the only time he did experiments was during the few months he spent at the Cavendish Laboratory.

Therefore, he is very self-aware and never conducts experiments himself.

If the experiment was simple, Bohr would have students from the Institute of Theoretical Physics go to the basement laboratory to perform the experiment.

But more often than not, Bohr waited for well-known laboratories around the world to publish experimental data and results before conducting corresponding theoretical physics research on their basis.

Bohr's approach is the correct approach for most people who are not strong in hands-on ability.

And Eddington's current performance, to put it mildly, is his unremitting pursuit of scientific truth.

To put it harshly, it actually means that he overestimates his abilities.

However, the above words were all complained by Chen Muwu in his heart, and he did not say them in front of Eddington.

After all, Eddington really helped him a lot. Chen Muwu was able to come to Cambridge University to study, and his first two papers were successfully published. Eddington took the greatest credit.

He also happily allowed himself to use the telescope on the rooftop of Cambridge University, so that Chen Muwu could "discover" the ninth planet in the solar system hidden beyond Neptune.

So since Eddington expressed such a strong intention to participate in the experiment, Chen Muwu certainly could not refuse him directly.

But Eddington offered to help, so let this matter go.

Although it is said that whether it is hydrogen, deuterium or helium-3 produced by the reaction, these three substances before and after the reaction are not radioactive and are relatively safe for the human body, this does not mean that this artificial nuclear fusion experiment is not radioactive. any danger.

First of all, the spherical electrode of the particle accelerator will generate a high voltage of millions of volts. You must carefully wear classic isolation clothes and take various insulation measures to prevent the human body from being broken down by static electricity.

Also, both hydrogen and deuterium are flammable gases.

In this environment, it is necessary to prevent the occurrence of open flames and the generation of electric sparks. It is a trivial matter for hydrogen and deuterium to burn, but it is a great pleasure to explode after mixing with air.

The key to the problem is that it doesn't matter if Chen Muwu and Eddington are injured. If the particle accelerator, which is regarded as a treasure, is blown up, Rutherford may really fight Chen Muwu.

Eddington's enthusiasm was definitely hard to refuse, so Chen Muwu made up his mind to let him help in name. However, in fact, all operations had to be completed by himself, and Eddington was still far away. Just stand aside and be a spectator.

Thinking of this, Chen Muwu smiled and responded to Eddington: "Okay, Professor Eddington, I will call the British Air Company and ask them to prepare a tank of deuterium gas as soon as possible and transport it to the University of Cambridge. ."

The Cavendish Laboratory could have chandeliers upstairs and downstairs, but it couldn't install telephones in every room.

Chen Muwu could only go to a room with a telephone and order the smallest tank of liquid deuterium from British Air Company.

The price of liquid deuterium is not too expensive, and the Cavendish Laboratory will pay the full price, but the Air Company is actually very unwilling to do this work.

First, the preparation of liquid deuterium requires lower temperatures and is troublesome to operate.

Second, the quantity required by Chen Muwu is too small, and it is not cost-effective to open the machine once.

However, even if it was reluctant, the Air Company did not refuse this request.

The University of Cambridge is the best institution of higher learning in the UK. With Chen Muwu in the Cavendish Laboratory, new discoveries may be made in research at any time. Liquid deuterium is the best example.

As long as it has a good relationship with the Cavendish Laboratory, if some of their discoveries happen to be related to low-temperature physics in the future, the Air Company may be able to successfully obtain authorization to transform the technical discoveries into industrial applications, and then use them to Reap benefits and benefits.

During the phone call, British Air Company assured Chen Muwu that it would liquefy the separated liquid deuterium as soon as possible and send the canister to Cambridge University as soon as possible.

Although this process is very fast, Chen Muwu estimates that he will have to wait for a few days no matter what.

He explained his thoughts to Eddington and asked the director of the observatory to calm down and go back to wait for the news.

Whenever the British Air Company delivers the liquid deuterium needed for the experiment, I will definitely go to the rooftop to find Eddington as soon as possible and ask him to go to the particle accelerator again to help with the experiment.

However, Eddington seems to have his own views on this matter.

"Chen, why can't we prepare deuterium gas directly in the Cavendish Laboratory?"

Hearing this question, Chen Muwu felt angry and funny. The call he just made seemed to be in vain.

"Professor, to be honest, I also wanted to make it in the laboratory, but when I discovered that the instrument for liquid deuterium was not in the Cavendish Laboratory, it was in the David Faraday Laboratory at the Royal Institution of London." If you have to go all the way to London and back just to prepare a small amount of liquid deuterium, you might as well wait for British Air Company to prepare it and send the canned deuterium gas over. Basically, the time difference between the two is not much. . "

"No, no, no," Eddington shook his head, "Chen, that's not what I meant. What I want to ask is, since the experiment we are going to do is to use accelerated deuterium nuclei to bombard the deuterium in the target, and then obtain nitrogen. Element. Then why can't we analogize it by directly bombarding protons with protons, and then we can get deuterons?"

Okay, okay, Eddington asked another "good" question.

The flaws in his latest speech became more dense, and Chen Muwu didn't know where to start.

Eddington thought that the experiment Chen Muwu was going to do was to bombard deuterium with deuterium to produce helium-4. This view was quite understandable.

Because Eddington’s idea at the beginning was to fuse four hydrogens into one helium-4. With deuterium, it would not only reduce the number of particles participating in the fusion reaction by half, but also help Eddington solve a problem that he had not thought of before. Okay big question.

That is, the four protons carry four positive charges, while the generated helium-4 nucleus only carries two positive charges.

As a result, when four protons are fused, two additional negatively charged electrons must be added. These six particles must participate at the same time in order to achieve charge balance before and after the nuclear reaction.

The two deuterons carry two positive charges. This time, no electrons are needed to participate in the reaction, and the charge balance can be achieved.

Because current physicists still don't know that there are two kinds of strong and weak interactions between microscopic particles, they all think that whether charged particles repel or attract, it is the effect of Coulomb force.

In Eddington's initial theory, regardless of the four protons and two electrons, the probability that these six moving particles must come together at the same time to aggregate into a new particle is very low.

It is only said that there is both attraction and repulsion among these six particles. The Coulomb force will deflect their orbits and prevent fusion from occurring.

Therefore, in Eddington's calculations, the particles must gain enough kinetic energy, that is, after the temperature is high enough, they can break through the obstacles of the Coulomb force and let them finally come together.

This high enough temperature should be tens of billions of degrees after calculation.

According to estimates of the actual sun, the temperature in its central area can only be about 4000 million degrees, which is several orders of magnitude different from the theory.

Therefore, as soon as Eddington's fusion theory was proposed, it was rejected by other astronomers and considered to be completely nonsense.

Eddington heard that Chen Muwu was going to use deuterium to conduct experiments, and subconsciously brought it into the reaction of deuterium and deuterium to produce helium-4.

He believes that from six particles participating in the reaction to two particles participating in the reaction, the repulsive effect caused by the Coulomb force may be reduced, so the temperature required for the reaction is also likely to be reduced.

Bombarding deuterium with deuterium can indeed produce a nuclear reaction, but the final product is not helium-4 as Eddington imagined, but hydrogen-3, which is tritium.

In the original space and time, Rutherford and Olyphant used this reaction to find the second isotope of hydrogen.

Chen Muwu felt that if he had extra time this time, he could pretend to be ignorant and try it out, and take the right to discover tritium into his own name.

But the idea that Eddington proposed at the end of his words, bombarding protons with protons to produce deuterons, made Chen Muwu dumbfounded.

Bombard protons with protons, and the two protons will first fuse into diprotons, which are helium-2 nuclei without neutrons.

Then one of the protons emits a positron and an electron neutrino outward through the weak interaction, turning into a neutron, turning helium-2 into deuterium-2.

Because the mass of one deuteron is greater than the mass of two hydrogen nuclei, according to the mass-energy equation, this reaction is an energy-absorbing reaction, and the energy required is approximately on the order of millions of electron volts.

Accelerating protons to this energy is not difficult for the Cavendish Laboratory's particle accelerator.

The difficulty is that after generating a helium-2 nucleus, this two-proton nucleus will have a probability of more than 99.99% that it will decay back into two protons and separate in less than one nanosecond.

The probability of a helium-2 nucleus decaying into a deuteron is less than [-] in [-].

This reaction is common in stars such as the sun, because of the huge size of stars.

Moreover, the protons and protons in the sun are not combined together through high energy, but through the quantum tunneling effect to break through the Coulomb barrier, and the average reaction time is on the order of hundreds of millions of years.

But for physicists, trying to reproduce this reaction in the laboratory is much more difficult than finding a needle in a haystack.

It can only be said that Eddington's idea is a good one, but Chen Muwu hopes that he will not think about it next time.

But he couldn't tell Eddington directly, so he could only find excuses to push the matter away.

"Professor, have you seen the relevant papers published by our laboratory after the particle accelerator was built?"

Eddington shook his head: "I really don't know that. I only know that you created an amazing big guy. Chen, are there any new discoveries in those papers?"

"It's just ordinary, nothing extraordinary."

Chen Muwu thought about Versailles a little, and in the eyes of someone who had experienced it, those reactions were indeed just like that.

But from zero to one, from nothing to something, is an amazing thing in itself.

What he said was so mysterious that Eddington was even more confused: "Then why are you mentioning these papers?"

"Professor, I want to say that although I haven't made any great discoveries, I have used accelerated protons to bombard other target elements, and I have obtained several existing or newly discovered atomic nuclei.

“But if you carefully read the papers published by the laboratory, you will know that deuterons have never been generated on this accelerator.

"Is this because no one in the laboratory is doing experiments on proton bombardment of hydrogen?
"On the contrary, it's because someone has already tried it. At least in this accelerator, the fusion reaction between hydrogen nuclei cannot occur. It's just a collision between two spheres of the same shape, size and mass.

"Let me make it more clear. Deuterium cannot be produced using a particle accelerator. We can only wait for the British Air Company to send liquid deuterium before we can proceed with the next experiment."

(End of this chapter)