When he saw the group of discharge tubes in front of him, Xu Yun couldn't help but feel a sense of witnessing history.
Low pressure gas discharge tube.
This can be said to be an enlightenment device for human beings to truly touch the microscopic world. In addition, it also has a relatively standardized name in concept.
That is......
Low pressure gas tube.
Of course.
The concept of electronic tubes has not yet been born, and it would not really appear until 1904.
At that time, John Ambrose Fleming, a student of Wheat, came on the scene and invented the famous electronic diode.
Then in 1906, De Forest invented the triode.
After that, there are point contact transistors, semiconductor transistors, p-n diodes, and Nixie tubes...
Wait until 2022 when Xu Yun travels through time.
The gas discharge experimental device has been optimized to a limit at the laboratory level.
For example, SMD1206 represents the packaging ceiling, YINT represents the performance extreme, and GDT represents the peak surge absorption capacity, etc...
Let alone ordinary gas discharge tubes at that time.
Even Nixie tubes have been eliminated for a long time and have become a small category with slight collection value.
You can buy a pretty good glow clock by spending a few hundred yuan on a certain product - but you have to check whether it is a glow clock or a pseudo-glow clock before placing an order. If you have the conditions, buying one is actually pretty good.
interesting.
all in all.
Compared with 2022.
The experimental equipment prepared by Faraday and others this time is undoubtedly extremely simple.
But on the other hand.
Simple, but not shabby.
most of the time.
History ushered in a critical node under such conditions that later generations would call "even dogs can't stand it", thus opening a new chapter.
His eyes returned to reality.
After everything is ready.
Faraday put on his gloves and led Xu Yun and others to the equipment, ready to start...
Pump mercury.
The modified version of the Geissler tube...or the anti-inflammatory tube's air extraction outlet is set in the middle of the test tube. It roughly looks like a small opening is opened, and then a hose is used to connect the outside.
The operation process is to use an external pressure valve to extract the mercury in the tube.
Once all the mercury is removed, and the magnetic circuit of the armature in the external relay is closed, a vacuum degree of one hundred thousandth can be achieved. (A reader left a message asking if there are any related books. Here are two recommended ones, "" by Yang Jinji"
Gas Discharge", and Mr. Yan Zhang's "High Voltage Insulation Technology")
Then Faraday made a gesture to Kirchhoff, who quickly came to the other side of the table.
Then......
He held a handle that was more than half a meter long and began to manipulate it like a rocker.
That's right.
This coolie-style operation was the most effective way to extract a vacuum in 1850.
no way.
Limited by the times.
There are many ways to extract vacuum in later generations, such as mechanical pumps, molecular pumps, ion pumps, etc.
A better ion pump can achieve a vacuum of about 10^-12mbar.
However, the equipment in 1850 was not as fully mechanized as later generations. Before 1870, there were only two ways to extract vacuum:
Reciprocating vacuum pump or oil-sealed rotary vacuum pump.
The principle of the former is to use the piston in the pump chamber to perform reciprocating motion, and manually activate the pump chamber to inhale, compress and discharge the gas.
Therefore, it is also called a piston vacuum pump.
The oil-sealed rotary vacuum pump is a rotary variable volume vacuum pump that uses oil to seal the gaps between moving parts to reduce harmful spaces.
Relatively speaking, the latter is more efficient.
However, the oil-sealed rotary vacuum pump requires the use of a gas ballast device, and the preparation and operation steps are relatively complicated, so Faraday chose a reciprocating vacuum pump this time.
"Hey hoo, hey hoo!"
Looking at Kirchhoff turning the handle like a fitter twisting a screw, Xu Yun suddenly thought of Brother Donkey in Lao Su's copy...
anyway.
By the time I returned to reality, it was almost time for the female donkey I bought from Wuzhou Mountain to be sent to school.
When the time comes to squeeze it... ahem, it will require another head of labor.
so good.....
that's all.
About five minutes passed.
Kirchhoff stopped what he was doing, panted and wiped the sweat from his forehead, and said to Faraday:
"Professor, the mercury has been taken out, and the voltage regulator always shows normal."
Faraday nodded and said:
"Thank you for your hard work, Gustave."
Then he motioned to Riemann to lower the curtains to block out all the light.
He himself walked to the left side of the table, fumbled for a moment, and pressed a certain power switch.
soon.
As the power is turned on, the external coil begins to discharge, the voltage at the two poles of the discharge tube begins to increase, and an electromotive force appears in the tube.
And in the microscopic world that cannot be seen by the naked eye.
Countless electrons emitted from the cathode move toward the anode under the action of the electric field.
They encountered residual air molecules in the middle of the gap, and after a series of collisions, a large number of new electrons, positive and negative ions were produced.
Since electrons move very fast, a large number of electrons are concentrated in the front part of the forward direction.
The positive ions stayed at the rear, and formed a collection of electrons and positive ions in the tube - this collection had a name in later generations, called electron collapse.
at the same time.
There are also a large number of ions that undergo other changes:
They combine into normal gas atoms in the tube.
Classmates who were Ions in their previous lives should know this.
The so-called ion recombination actually refers to the process of electrons returning to positive ions.
When the electron returns to the atom.
It will emit the energy it carries in the form of light.
As the electron avalanche moves toward the anode, there are more and more electrons and positive ions inside.
On the one hand, this changes the electric field distribution in the discharge gap, and at the same time, the charges in the electron avalanche weaken the electric field inside the electron avalanche, thereby enhancing the recombination effect.
The recombination of electrons and positive ions will produce a large number of photons, and the photons act on the gas at the rear, causing these gases to undergo electric field ionization.
Then a second electron avalanche and a third electron avalanche occur.
The head and tail of each electron avalanche develop toward the anode and cathode respectively, and finally connect together.
until.......
piu——
With a small voice.
A complete ionized gas channel is formed, and the gas gap in the tube is broken down.
Also don't forget.
Faraday had previously filled the tube with mercury, a very volatile substance.
Although they have all been extracted from the naked eye, Kirchhoff is not the elder of the Soul Palace after all, so some mercury still remains on the tube wall.
Under the stimulation of voltage, they quickly formed mercury vapor.
then......
A blue-white light appeared inside the tube, making people unconsciously think of mio's blue-and-white bowl.
This is a light effect unique to mercury. If it is replaced by sodium, it will appear yellowish white.
See this situation.
Faraday couldn't help but leaned down and stared at the blue-white light in the coffin.
I don’t know whether he was lamenting the time or admiring the magic of Xiao Yan Pavilion. I just heard this old man who was nearly sixty years old murmuring:
"It's been 12 years..."
be honest.
Compared with the 6% vacuum tube 12 years ago, the image of today's Xiao Yan tube is indeed much clearer.
Faraday didn't even need a magnifying glass to see several intervals of different brightness, distributed in sequence from the cathode to the anode.
"one two three...."
Faraday counted carefully, turned to look at Xu Yun, and asked:
"Classmate Luo Feng, there are six light and dark areas in total?"
Xu Yun once said that 'Fat Fish' had not completed this experiment, so he simply spread his hands towards him:
"I can't come."
Faraday gave him a meaningful look and said nothing.
Then he called Weber and others to his side and recorded the phenomenon.
From an observational perspective.
Glow discharge is undoubtedly one of the more distinctive gas discharge phenomena.
When it occurs, the entire space in the arc gap is discharging, and the temperature will not be too high. What limits observation is actually the degree of vacuum.
The higher the vacuum, the easier it is for glow discharge to occur and the phenomenon is clearer.
The conditions of a vacuum degree of one hundred thousandth, even if it were moved forward a hundred years, would still be considered acceptable in 1950.
Therefore, Faraday and others could observe and write down notes freely.
"Gustave, please remember this."
"...Starting from the cathode, the first thing that appears is a very short dark area, which is slightly visible to the naked eye. Detailed observation requires the assistance of a magnifying glass..."
"The second area is close to the first layer, has moderate brightness, and can be observed with the naked eye..."
"The third piece glows faintly..."
"The fourth area has a clear boundary. The light is strongest on the boundary line, and then gradually becomes weaker..."
"The fifth block appears as a transition area, the original Faraday Dark Zone..."
Farah first observed and narrated, his tone slightly trembling.
Although I have already made some mental preparations, I can roughly guess that the experimental phenomena will be quite impactful.
But now that he saw these six clearly arranged areas, he still couldn't help but feel a complex emotion in his heart.
Twelve years ago, he really thought that there was only a Faraday dark zone in the Nixie tube...
He was like a fisherman who had a good harvest during the fish season and caught an eel on a certain beach.
He could roughly guess that more eels might be found in the sea in that direction, but he fell in love with the cuttlefish shoals in the other direction, so he gave up here.
Unexpectedly, with the improvement of accuracy, let alone the 'deep sea' behind the light.
Even near the Faraday Dark Zone, a tidal flat that he originally thought was "just that", there are actually huge wild croakers buried...
And the other side.
Looking at Faraday and others who were frantically recording the phenomenon, Xu Yun's expression remained relatively calm.
He conducted glow experiments more than once in later generations, and was still not surprised by the phenomenon itself.
And actually.
The areas that appear during the glow discharge process are not six areas, but seven areas...or eight areas...
The first one is called the Aston Dark Zone, which is a very thin layer of dark zone in front of the cathode.
in the original history.
It would not be discovered experimentally until 1968 by F.W. Aston.
In this area, the electrons have just left the cathode and their flight distance is still short.
The energy they get from the electric field is not enough to excite the gas atoms, so they don't emit light.
Next to the Aston Dark Zone is the cathode glow zone.
Since electrons have enough energy to excite atoms after passing through the Aston dark zone, when the cathode glow region returns to the ground state, this area emits light.
Behind them are the Crookes Dark Zone, Negative Glow Zone, Faraday Zone and Positive Glow Pillar Zone.
As for the last area that was not discovered by Faraday...
It is actually a collective name for two small areas, called the anode glow area and the anode dark area.
The conditions for the formation of these two small areas are relatively high, and they only appear when the current drawn by the anode is greater than the current that the plasma zone can normally provide.
Therefore, they are generally not regarded as common areas in discharge phenomena.
Among all the above areas, the most important is the positive glow column area.
The electron ion concentration in this area is about 10^15~10^16/m3, and the concentrations of the two are equal, so it is called plasma.
Actually.
This part of the area is dispensable for the glow phenomenon itself. In a short discharge tube, the positive column area will even disappear.
But in the derivative field, this thing is really cool:
Cutting-edge science and technology such as plasma coating, plasma etching, plasma physics, nuclear fusion, plasma propulsion, and electromagnetic fluid power generation in modern microelectronics are all related to it...
This chapter is not finished yet, please click on the next page to continue reading the exciting content! At the same time, the relationship between these technologies and the Zhenghui Pillar Area is not just a slight fluff, but one of the solid basic research supports.
Of course.
At present, Faraday and others do not know how big an impact these areas will have in the future - they have not even discovered the seventh area.
Influenced by the vision of the times.
They were completely unaware of what they had done and how much harder it would be to take the college entrance examination more than a hundred years later...
After recording the relevant data.
Faraday, Gauss and Weber discussed and analyzed the phenomenon on the spot.
Weber's eyes were fixed on the vacuum tube. At this time, one of the famous unlucky men in the history of physics showed his keen judgment:
"The first dark zone is much darker than the third dark zone...still much dimmer than the Faraday dark zone."
"But there is obviously an electromotive force exerted on this area, which means that the hardware equipment and the intensity of the 'field' are all consistent."
"Then there is probably only one reason for the appearance of the dark zone..."
Speaking of which.
Weber couldn't help but raise his head, looked at each other with Faraday and Gauss, and said in unison:
"energy!"
Xu Yun on the side heard this and his eyes narrowed.
The core reason why dark areas appear in glow discharges is that the excitation is small - if we leave aside the special case of the cathode dark area, it can be said that ionization does not occur in the other three dark areas.
The reason why these charged particles are not excited is because the energy of electrons is very low.
Just like eight and eight and a half branches, the area where they hit is the bright area, and the area where they come out to accumulate power is the dark area.
Although there is still a huge gap between energy and particle excitation.
But with today's scientific understanding, it is really amazing that Weber and others can think of the energy aspect.
Of course.
In addition to the abilities of Webber and others, a large part of the reason for this is attributed to the Mavericks:
It is precisely because he proposed the rudimentary theory of wave-particle duality that future generations like Weber were able to make conjectures more freely.
Then Faraday and others measured and recorded the test tubes, and then began the more important step...
Detect the nature of this ray.
First, Faraday walked to the test tube and pressed a certain switch.
With the switch activated.
A small round piece of wood that was originally attached to the inside of the tube wall was placed down, blocking the path of the light.
As the light path was blocked, within a few seconds, a clear shadow appeared on the right side of the test tube.
Faraday saw this and nodded slightly.
The left side of the test tube is the cathode and the right side is the anode.
Adding a small object between the two, and the shadow appearing on the right side, illustrates one thing:
The rays originate from the cathode.
Think of this.
Faraday couldn't help but look at Xu Yun and asked:
"Classmate Luo Feng, did Mr. Fat Fish name this beam of light?"
Xu Yun shook his head:
"No."
Faraday pondered for a moment, looked at Gauss and Weber again, and said after consideration:
"In that case, let's call it cathode ray."
Xu Yun was originally worried that Faraday would say some sexy name, such as Aurora or something like that, but he was relieved after hearing the cathode rays.
As for whether this is the inertia of history or a term that happened to come to Faraday's mind...
This is not something Xu Yun has the ability to understand.
all in all.
Make sure the source point of the light is behind the cathode.
Faraday's expression suddenly straightened, and his expression instantly became serious.
The left hand he placed behind his back even shook a few times in an extremely subtle way, but no one noticed this scene.
Then he turned around with a serious face and said to Kirchhoff:
