Hand rubbing nuclear fusion live in the wilderness

Chapter 465 Time Domain Matter Wave Lens
Just because ordinary viewers can't understand these technical terms doesn't mean that experts from various countries who are squatting in the live broadcast room can't understand.

Experts in alloy materials and mirror manufacturing, in particular, couldn't help but gasp when they heard this series of indices.

Radian error 0.0000108rad;

Specular IRI index 0.0000023m/km
They couldn't be more clear about what these data represent.

These indexes represent the top mirror polishing process.

In layman's terms, the mirror surface of the world's strongest ace pigeon 'Weber Telescope', which cost more than 100 billion meters of gold and took nearly 15 years to go to the sky, is far inferior to the beryllium-iridium alloy in front of us.

If the mirror surface of the Webb telescope is indexed, the arc error before and after rapid cooling is about 0.0002rad, and the IRI index of the mirror surface will be higher, which may reach 0.00007m/km.

Compared with the beryllium-iridium alloy mirror in front of you, the index data can differ by ten or even dozens of times.

Of course, this is also related to the different materials and structures used by the two.

Although the mirror surface of the Webb telescope is also made of beryllium alloy, it is not a beryllium-iridium alloy, and its thermal expansion coefficient is definitely inferior to the latter.

And the structure is even better.

When the Webb telescope is launched, due to the capacity of the launch rocket, it will try its best to reduce the weight of the goods sent.

Among them, there is adjustment work for the mirror surface.

Although the density of beryllium alloy is very low, only 1.85 g/cm, far lower than iron's 7.86 g/cm, it is still a metal after all.

The mirrors of the Weibo telescope are all made of beryllium alloy, so in order to reduce the weight of the mirror, the staff first cut off most of the back of the beryllium mirror blank, leaving only a thin "rib" structure.

Although most of the metal is gone, this rib is enough to keep the entire shape of the mirror stable.

And this operation can make each part very light.A beryllium lens has a mass of 20 kg.

Greatly reduces the weight of the mirror.

And for the Korean won.

20 kilograms, let alone a giant mirror with a diameter of more than [-] meters, even the beryllium-iridium alloy in his hand is far more than this weight.

Stealing the mirror surface and reducing the weight will also reduce the stability of the mirror itself to a certain extent, but the degree of reduction is within the acceptable range.

But for the won, there is no need to do so.

He has a space shuttle with enough thrust to send a super-heavy space telescope into space.

Therefore, it is the goal to improve the reflection effect of the mirror as much as possible.

After the low-temperature detection of the beryllium-iridium alloy was completed, Han Yuan recorded all the changes in the shape of the reflector segment caused by exposure to low temperature, as well as related data, and then began to calculate and adjust the grinding and polishing angle, speed, radian, etc. of the mirror surface. information.

The grinding and polishing of the space telescope mirror cannot be completed at one time. Even if he calculated the grinding and polishing data almost perfectly through the data model in advance, the polished mirror still had flaws.

For example, the radian error of a certain part is a bit too large, the flatness of a certain part of the lens is too high, and so on.

These large and high places still meet the standard values, but they can be further optimized and adjusted through calculations to improve the reflection performance of the mirror.

Although it is troublesome, it is totally worth it for him.

The higher the performance of the mirror, the clearer what can be seen.

In particular, Han Yuan also wants to use this space telescope to carefully observe the situation outside the solar system and see what happened outside the solar system.

Therefore, the grinding and polishing of the mirror surface must be more refined.

After the low-temperature test was completed, according to the recorded data, Won once again adjusted the beryllium-iridium alloy mirror.

This adjustment took another five days, but it was worth it.

The third adjustment reduced the flatness of almost every part of the mirror to 0.00006m/km.

Don't look at it is only one ten-thousandth point missing, the improved performance may be less than one percent or even one thousandth.

But after the final manufacturing and assembly into performance, this performance improvement can increase the distance that this space telescope can see by several light-years, or even tens of light-years.

If a small difference is placed in the universe counted by light years, the resulting error can have an unimaginably large impact.

In this way, time passed little by little, and after nearly 20 days of tossing, Won finally completed all the work on the beryllium-iridium alloy mirror.

Test, adjust, test, adjust; test again, adjust again.
A whole half a month was spent on this.

It can be said that this is the single part that took the longest to manufacture since the live broadcast, and it is also the most precise of all parts.

Even the nanoscale lithography machines and nanoscale carbon-based chips that have been manufactured before do not have a precision as low as five nanometers.

However, the time spent is totally worth it. This experimental beryllium-iridium alloy mirror meets the basic requirements in various tests.

And under his continuous improvement, the various indexes of the final mirror surface far exceed the original settings.

If, say, in previous targets, this space telescope can see the infrared light emitted by the universe 130 billion years ago.

So now, Won estimates that this number of years can be increased by about [-] million years.

Although the percentage of improvement is not much, it is very difficult for the current universe.

Although infrared light has quite good propagation properties, the longer the infrared light is, the higher the probability of being annihilated in the universe.

And even if there are occasional ones that can reach the earth, it requires a fairly high-performance space telescope to capture them.

Because they pass through the vast universe, they are so faint that it is difficult to be found.

After completing the beryllium-iridium alloy mirror used in the experiment and collecting various data, the rest is to start manufacturing the real space telescope mirror.

Won did not do this work himself, handing it over to the X-1 industrial robot, and he himself started to manufacture another key part of the space telescope.

What he made by himself is the three-stage reflector and the fine steering mirror in the mirror system.

In an infrared sensing outer space telescope device, there are three basic system structures.

Mirror structure system, integrated scientific instrument structure system, and control structure system.

Compared with the latter two, the former is the core part of the entire telescope.

Also the hardest part to make.

Taking the infrared telescope he designed as an example, a complete mirror structure includes four sets of mirrors: primary mirror, secondary mirror, tertiary reflector, and fine steering mirror.

Among them, the main mirror has a total of 18 yuan, and the secondary mirror, tertiary mirror, and fine steering mirror are all one piece.

These 21 mirrors form a complete observation mirror.

One of them faces space, and the secondary mirror faces the primary mirror.

Its shape is somewhat similar to an open umbrella.

It's just that this 'umbrella' faces the sky from the inside.

The main mirror is like a raincloth that is put on the ground after the umbrella is opened. The rain in the sky is the light transmitted from the distant outer space, which is collected after falling on the raincloth.

The secondary mirror is the 'umbrella handle'. Because of the special arc shape of the primary mirror, the infrared light falling on it will be concentrated and reflected to the umbrella handle.

The umbrella handle (secondary mirror) will reflect the light to the third-level reflector again.

If you still use the umbrella as a metaphor, then the three-stage reflector and the fine steering mirror are the fixed springs on the umbrella and the skeleton of the umbrella.

Behind them are integrated scientific instrument structures.

The light and image transmitted back from the secondary mirror can be further stabilized, and then transmitted to different scientific load modules according to different types for analysis.

The analyzed data is then transmitted back to the earth through the communication module.

The whole process ends here.

This is how the infrared light-reflecting space telescope designed by Won observes the universe and draws the whole process of star maps.

Its principle is ordinary optical refraction, but what is refracted is infrared rays that cannot be seen by the human eye.

Of course, in addition to observing the universe by refracting infrared light, he also designed a space telescope and a set of exoplanet discovery modules.

The role of this module is different from that of the former, which is used to observe the universe tens of billions of light-years away.

The role of the latter is to find out whether there are planets with similar conditions to the earth within tens of light-years of the solar system, and to further obtain valuable clues for unraveling the "suspense" of extraterrestrial life.

In Won's hands, of course, its role is to explore what's in close outer space beyond the solar system.

The words left to him by the former host of Taishan base still remain in his mind.

Plus those giant insects that apparently came from outside our solar system.

What exists outside the solar system interests Won more than aliens.

The manufacture of three-stage reflectors and fine steering mirrors is more difficult than the manufacture of primary mirrors.

This principle is actually the same as the mask plate in the lithography machine.

The primary mirror is the primary mask, and the tertiary reflector and fine steering mirror are the final mask.

It needs to receive all the light reflected by the primary mirror, and ensure that there is no loss of these light and images, and even further stabilize it.

The difficulty of the two is like carving the same painting on walnuts and rice grains.

Although both are difficult, the latter is significantly more difficult than the former.

After handing over the manufacturing of the primary and secondary mirrors to the X-1 industrial robot, Won came to the CNC factory.

Experimental beryllium-iridium alloy mirrors can be fabricated in a physics laboratory, but mirrors for tertiary reflectors and fine turning mirrors cannot.

The tools in the physics laboratory cannot meet the level requirements for manufacturing this kind of mirror, so it can only be completed with the help of more sophisticated equipment in the CNC factory.

There are no changes in the materials used to make the tertiary mirrors and fine turning mirrors, both of which are beryllium iridium alloys.

The difference is that the three-stage reflector and the fine steering mirror not only require higher precision, but also need to have a cooling system.

Strictly speaking, the temperature of the three-stage reflector and the fine steering mirror is lower than that of the primary mirror and the secondary mirror by one level or even two levels.

Because only a lower temperature can better and more accurately receive the infrared light refracted by the secondary mirror.

If the temperature is the same, there is a certain probability that the infrared light received by the three-stage reflector and the fine steering mirror will be spectrally blurred.

Once the spectrum is blurred, the computer cannot restore the captured deep space, and even if it is restored, problems such as distortion will occur.

This is absolutely not allowed in a high-precision space telescope.

Taking out the beryllium-iridium alloy prepared in advance, Han Yuan got busy in the CNC factory.

Compared with the main mirror with some curvature, the three-stage reflector and the fine steering mirror have no curvature.

They are flat mirror surfaces.

From this point of view, it is more conducive to the processing of the mirror surface.

It's just that for higher precision, it still needs to carry a cooling system to make them more difficult to process.

Higher mirror fineness is not too difficult for Won.

After writing the NC program, he gave the beryllium-iridium alloy mirror to the NC equipment, and he thought about how to cool down the three-stage reflector and the fine steering mirror.

The working temperature of the primary mirror and the secondary mirror is to work in the extremely low temperature of minus 220 degrees.

This temperature is calculated by Won through the properties of beryllium-iridium alloy.

In an environment of -223°C, the infrared heat radiation of the beryllium-iridium alloy itself can be ignored, and will not affect the reflection of external infrared rays by the mirror.

The temperature requirements of the three-stage reflector and the fine steering mirror are even lower.

Of course, if it is simply to create such a temperature, there are many ways for him.

Such as laser refrigeration, such as helium refrigeration and so on.

After thinking about it, Won targeted two ways.

The first is liquid helium refrigeration. The lowest limit of this method can reduce the temperature to close to -270°C.

But this method has a disadvantage. Liquid helium refrigeration is more suitable for indoor refrigeration. If it is in a vast space, it is not very suitable.

Of course, Won can choose to hollow out the lens and arrange pipelines inside the lens, in this way to reduce the temperature of the mirror.

But it also has disadvantages, that is, the temperature of the mirror surface may be uneven, and the temperature of liquid helium is not easy to control.

However, this method is still included in the plan by the won.

The second is the 'time domain matter wave lens' cooling method.

This kind of term is a term from the physics world, but it really comes from the physics world.

The principle is similar to laser cooling, only more complex.

In simple terms, it reduces the temperature of the system by slowing down the speed of particle motion.

By combining the Bose-Einstein condensate (BEC) excitation with a magnetic lens, a 'time-domain matter-wave lens system' can be fabricated.

By placing the focal point of the 'time domain matter wave lens' at infinity, the total internal kinetic energy in the system can be reduced to 38 picokelvin.

In this way, it is theoretically possible to reduce the temperature in the system domain to as low as seventeen picokelvin.

Seventeen picokelvins, or -256.15 degrees Celsius.

Although this temperature is not as high as the limit of liquid helium refrigeration, it is relatively controllable and more stable.

The disadvantage is that it is very complicated to manufacture and requires a large calculation load.

Both methods have their pros and cons, so Won decided to try both to see which one was more suitable.

(End of this chapter)