最近有一項(xiàng)新的研究表明,人工智能可以用來更精確地控制核聚變反應(yīng),這或許能夠加快核聚變作為一種實(shí)用能源的發(fā)展。
該人工智能程序是由位于倫敦的人工智能研究公司DeepMind(屬于Alphabet旗下企業(yè))的計(jì)算機(jī)專家和位于瑞士埃居布朗的瑞士聯(lián)邦理工學(xué)院(EPFL)瑞士等離子體中心(Swiss Plasma Center)的物理學(xué)家共同開發(fā)的。這項(xiàng)突破性研究已經(jīng)發(fā)表于2月16日的科技期刊《自然》(Nature)上。
目前公認(rèn)最有希望的可控核聚變技術(shù)叫做“托卡馬克裝置”,它本質(zhì)是上一種利用磁約束來實(shí)現(xiàn)受控核聚變的環(huán)形容器,在通電時,氫會在該裝置中被加熱至等離子態(tài),而此時托卡馬克裝置內(nèi)部的溫度可以達(dá)到1億攝氏度以上。在這種狀態(tài)下,氫原子的原子核就會發(fā)生聚合,并且釋放大量能量。
但是由于等離子體的溫度級高,它是無法被任何物質(zhì)約束的,因此它只能懸浮在托卡馬克裝置內(nèi)部,用強(qiáng)大的磁場進(jìn)行約束。核聚變產(chǎn)生的熱量能夠用來產(chǎn)生蒸汽,蒸汽就可以驅(qū)動渦輪機(jī)發(fā)電了。
而DeepMind公司開發(fā)的人工智能軟件能夠?qū)W會控制托卡馬克裝置內(nèi)部的約束磁場,從而操縱等離子體形成科學(xué)家利用舊的控制方法不敢輕易嘗試的新結(jié)構(gòu),以產(chǎn)生更高的能量。
“這樣一來,我們就可以向前推進(jìn)試驗(yàn)了,因?yàn)楝F(xiàn)在我們能夠承擔(dān)一些以前不敢承擔(dān)的風(fēng)險”。參與該項(xiàng)目的瑞士等離子體中心的科學(xué)家安布羅吉奧·法索利說,“我們嘗試的一些等離子態(tài)已經(jīng)非常接近系統(tǒng)的極限,甚至有可能崩潰或者導(dǎo)致系統(tǒng)損壞。如果沒有人工智能技術(shù)給予我們的信心的話,我們是不敢冒這個險的?!?/p>
在過去的兩個星期里,核聚變技術(shù)迎來了重大的突破。兩周前,一群歐洲物理學(xué)家在英國的歐洲聯(lián)合環(huán)實(shí)驗(yàn)室(Joint European Torus Laboratory)成功進(jìn)行了有史以來最大功率的可控核聚變試驗(yàn)。該試驗(yàn)產(chǎn)生了59兆焦耳的能量(相當(dāng)于大約11兆瓦),且核聚變過程維持了5秒鐘。功率達(dá)到了1997年創(chuàng)下的最高紀(jì)錄的一倍。
歐洲聯(lián)合環(huán)實(shí)驗(yàn)室的托卡馬克裝置要比瑞士等離子中心使用的TCV托卡馬克裝置大得多,也強(qiáng)大得多。瑞士研究團(tuán)隊(duì)的成員介紹道,瑞士等離子中心的TCV托卡馬克裝置最多只可以維持2秒鐘左右的核聚變反應(yīng)。
不過瑞士等離子體中心使用的這類人工智能算法,或許也能夠適用于更大規(guī)模的核聚變反應(yīng)堆。目前全世界最大的核聚變反應(yīng)堆正在法國南部進(jìn)行建設(shè),包括歐盟、美國、中國和俄羅斯在內(nèi)的多個國家政府都為該項(xiàng)目提供了支持。
專家們希望,在本世紀(jì)下半葉,可控核聚變技術(shù)將足以為世界部分地區(qū)提供電力。核聚變可以將從相對容易獲得的氘、氚等元素中獲取幾乎無限的能源,而且既不會排放溫室氣體,其產(chǎn)生的放射性廢物也相對較少,并且它排放的廢物在一個世紀(jì)內(nèi)就會分解殆盡。相比之下,目前所有核電站采用的裂變反應(yīng)堆則會產(chǎn)生大量的高放射性廢料,其中一些廢料的毒害性會持續(xù)存在數(shù)萬年。
不過,目前的核聚變技術(shù)還很不成熟,短期內(nèi)實(shí)現(xiàn)商用的可能性還是很小的。所以雖然全球都忙著低碳環(huán)保、對抗全球變暖,但短期內(nèi)核聚變在這方面似乎還幫不上什么忙。
DeepMind公司的人工智能技術(shù)負(fù)責(zé)人普希米特·科利指出,該項(xiàng)目充分表明,這家研究公司有能力在物理學(xué)領(lǐng)域產(chǎn)生重大影響。2020年該公司還展示過一個名叫AlphaFold的人工智能系統(tǒng),它能夠通過蛋白質(zhì)的基因序列有效預(yù)測它的三維形狀。這是生物學(xué)的一個重大突破,很有可能在藥物開發(fā)等領(lǐng)域產(chǎn)生深遠(yuǎn)影響。不過在此之前,DeepMind公司最出名的人工智能產(chǎn)品就是它的AlphaGo了,這款A(yù)I應(yīng)用程序甚至戰(zhàn)勝過包括柯潔在內(nèi)的眾多頂級圍棋高手。
DeepMind的這款核聚變控制程序使用了一種叫做“強(qiáng)化學(xué)習(xí)”的方法,系統(tǒng)首先會在模擬器里學(xué)習(xí)和試錯。該技術(shù)最令人關(guān)注的一個問題是,是模擬器是否構(gòu)建得足夠好,能否讓AI程序在學(xué)習(xí)完畢后有效控制一個真實(shí)的托卡馬克裝置。參與該項(xiàng)目的DeepMind公司研究員喬納斯·布赫里說:“我們認(rèn)為,模擬器可能做得還不夠好?!?/p>
首先是模擬器沒有準(zhǔn)確捕捉到一個真實(shí)的托卡馬克裝置中存在的所有變量。不過布赫里表示,他們在模擬器里加入了一些隨機(jī)參數(shù)來代表這些變量,因此DeepMind的AI程序仍然可以訓(xùn)練出足夠靈活的人工智能,能夠?qū)⒃谀M器里學(xué)來的知識應(yīng)用到真實(shí)的托卡馬克裝置上。
其次,為了控制托卡馬克裝置內(nèi)部的等離子體,控制算法的決策速度必須非常快,甚至要可以對磁場做出微秒級的調(diào)整。但是很多人工智能系統(tǒng)的計(jì)算時間過長,目前仍然無法很好地適應(yīng)這種高速的環(huán)境。
有鑒于此,DeepMind團(tuán)隊(duì)使用了兩個組件來訓(xùn)練人工智能系統(tǒng)。一個是大型神經(jīng)網(wǎng)絡(luò),它的設(shè)計(jì)結(jié)構(gòu)較為松散,主要用來模擬人腦的功能,它能夠就磁場的變化如何影響等離子態(tài)做長期預(yù)測。然后這個網(wǎng)絡(luò)會被用來訓(xùn)練一個規(guī)模上要小很多的系統(tǒng),這個系統(tǒng)可以通過學(xué)習(xí),掌握如何實(shí)施好第一個網(wǎng)絡(luò)推薦的最佳方案。與托卡馬克裝置直接交互的只有那個小網(wǎng)絡(luò),這樣它才能夠在50微秒內(nèi)做出決策。(財富中文網(wǎng))
譯者:樸成奎
最近有一項(xiàng)新的研究表明,人工智能可以用來更精確地控制核聚變反應(yīng),這或許能夠加快核聚變作為一種實(shí)用能源的發(fā)展。
該人工智能程序是由位于倫敦的人工智能研究公司DeepMind(屬于Alphabet旗下企業(yè))的計(jì)算機(jī)專家和位于瑞士埃居布朗的瑞士聯(lián)邦理工學(xué)院(EPFL)瑞士等離子體中心(Swiss Plasma Center)的物理學(xué)家共同開發(fā)的。這項(xiàng)突破性研究已經(jīng)發(fā)表于2月16日的科技期刊《自然》(Nature)上。
目前公認(rèn)最有希望的可控核聚變技術(shù)叫做“托卡馬克裝置”,它本質(zhì)是上一種利用磁約束來實(shí)現(xiàn)受控核聚變的環(huán)形容器,在通電時,氫會在該裝置中被加熱至等離子態(tài),而此時托卡馬克裝置內(nèi)部的溫度可以達(dá)到1億攝氏度以上。在這種狀態(tài)下,氫原子的原子核就會發(fā)生聚合,并且釋放大量能量。
但是由于等離子體的溫度級高,它是無法被任何物質(zhì)約束的,因此它只能懸浮在托卡馬克裝置內(nèi)部,用強(qiáng)大的磁場進(jìn)行約束。核聚變產(chǎn)生的熱量能夠用來產(chǎn)生蒸汽,蒸汽就可以驅(qū)動渦輪機(jī)發(fā)電了。
而DeepMind公司開發(fā)的人工智能軟件能夠?qū)W會控制托卡馬克裝置內(nèi)部的約束磁場,從而操縱等離子體形成科學(xué)家利用舊的控制方法不敢輕易嘗試的新結(jié)構(gòu),以產(chǎn)生更高的能量。
“這樣一來,我們就可以向前推進(jìn)試驗(yàn)了,因?yàn)楝F(xiàn)在我們能夠承擔(dān)一些以前不敢承擔(dān)的風(fēng)險”。參與該項(xiàng)目的瑞士等離子體中心的科學(xué)家安布羅吉奧·法索利說,“我們嘗試的一些等離子態(tài)已經(jīng)非常接近系統(tǒng)的極限,甚至有可能崩潰或者導(dǎo)致系統(tǒng)損壞。如果沒有人工智能技術(shù)給予我們的信心的話,我們是不敢冒這個險的。”
在過去的兩個星期里,核聚變技術(shù)迎來了重大的突破。兩周前,一群歐洲物理學(xué)家在英國的歐洲聯(lián)合環(huán)實(shí)驗(yàn)室(Joint European Torus Laboratory)成功進(jìn)行了有史以來最大功率的可控核聚變試驗(yàn)。該試驗(yàn)產(chǎn)生了59兆焦耳的能量(相當(dāng)于大約11兆瓦),且核聚變過程維持了5秒鐘。功率達(dá)到了1997年創(chuàng)下的最高紀(jì)錄的一倍。
歐洲聯(lián)合環(huán)實(shí)驗(yàn)室的托卡馬克裝置要比瑞士等離子中心使用的TCV托卡馬克裝置大得多,也強(qiáng)大得多。瑞士研究團(tuán)隊(duì)的成員介紹道,瑞士等離子中心的TCV托卡馬克裝置最多只可以維持2秒鐘左右的核聚變反應(yīng)。
不過瑞士等離子體中心使用的這類人工智能算法,或許也能夠適用于更大規(guī)模的核聚變反應(yīng)堆。目前全世界最大的核聚變反應(yīng)堆正在法國南部進(jìn)行建設(shè),包括歐盟、美國、中國和俄羅斯在內(nèi)的多個國家政府都為該項(xiàng)目提供了支持。
專家們希望,在本世紀(jì)下半葉,可控核聚變技術(shù)將足以為世界部分地區(qū)提供電力。核聚變可以將從相對容易獲得的氘、氚等元素中獲取幾乎無限的能源,而且既不會排放溫室氣體,其產(chǎn)生的放射性廢物也相對較少,并且它排放的廢物在一個世紀(jì)內(nèi)就會分解殆盡。相比之下,目前所有核電站采用的裂變反應(yīng)堆則會產(chǎn)生大量的高放射性廢料,其中一些廢料的毒害性會持續(xù)存在數(shù)萬年。
不過,目前的核聚變技術(shù)還很不成熟,短期內(nèi)實(shí)現(xiàn)商用的可能性還是很小的。所以雖然全球都忙著低碳環(huán)保、對抗全球變暖,但短期內(nèi)核聚變在這方面似乎還幫不上什么忙。
DeepMind公司的人工智能技術(shù)負(fù)責(zé)人普希米特·科利指出,該項(xiàng)目充分表明,這家研究公司有能力在物理學(xué)領(lǐng)域產(chǎn)生重大影響。2020年該公司還展示過一個名叫AlphaFold的人工智能系統(tǒng),它能夠通過蛋白質(zhì)的基因序列有效預(yù)測它的三維形狀。這是生物學(xué)的一個重大突破,很有可能在藥物開發(fā)等領(lǐng)域產(chǎn)生深遠(yuǎn)影響。不過在此之前,DeepMind公司最出名的人工智能產(chǎn)品就是它的AlphaGo了,這款A(yù)I應(yīng)用程序甚至戰(zhàn)勝過包括柯潔在內(nèi)的眾多頂級圍棋高手。
DeepMind的這款核聚變控制程序使用了一種叫做“強(qiáng)化學(xué)習(xí)”的方法,系統(tǒng)首先會在模擬器里學(xué)習(xí)和試錯。該技術(shù)最令人關(guān)注的一個問題是,是模擬器是否構(gòu)建得足夠好,能否讓AI程序在學(xué)習(xí)完畢后有效控制一個真實(shí)的托卡馬克裝置。參與該項(xiàng)目的DeepMind公司研究員喬納斯·布赫里說:“我們認(rèn)為,模擬器可能做得還不夠好。”
首先是模擬器沒有準(zhǔn)確捕捉到一個真實(shí)的托卡馬克裝置中存在的所有變量。不過布赫里表示,他們在模擬器里加入了一些隨機(jī)參數(shù)來代表這些變量,因此DeepMind的AI程序仍然可以訓(xùn)練出足夠靈活的人工智能,能夠?qū)⒃谀M器里學(xué)來的知識應(yīng)用到真實(shí)的托卡馬克裝置上。
其次,為了控制托卡馬克裝置內(nèi)部的等離子體,控制算法的決策速度必須非常快,甚至要可以對磁場做出微秒級的調(diào)整。但是很多人工智能系統(tǒng)的計(jì)算時間過長,目前仍然無法很好地適應(yīng)這種高速的環(huán)境。
有鑒于此,DeepMind團(tuán)隊(duì)使用了兩個組件來訓(xùn)練人工智能系統(tǒng)。一個是大型神經(jīng)網(wǎng)絡(luò),它的設(shè)計(jì)結(jié)構(gòu)較為松散,主要用來模擬人腦的功能,它能夠就磁場的變化如何影響等離子態(tài)做長期預(yù)測。然后這個網(wǎng)絡(luò)會被用來訓(xùn)練一個規(guī)模上要小很多的系統(tǒng),這個系統(tǒng)可以通過學(xué)習(xí),掌握如何實(shí)施好第一個網(wǎng)絡(luò)推薦的最佳方案。與托卡馬克裝置直接交互的只有那個小網(wǎng)絡(luò),這樣它才能夠在50微秒內(nèi)做出決策。(財富中文網(wǎng))
譯者:樸成奎
New research shows that artificial intelligence can be used to more precisely control a nuclear fusion reaction, potentially helping accelerate the development of nuclear fusion as a practical power source.
The A.I. was developed by computer scientists at DeepMind, the London-based A.I. research company that is part of Alphabet, and physicists from the Swiss Plasma Center at EPFL in Ecublens, Switzerland. The breakthrough research was published in the peer-reviewed scientific journal Nature on February 16.
The most promising path toward fusion power involves a doughnut-shaped reactor, called a tokamak, in which hydrogen is superheated into a state called plasma. This happens at temperatures of more than 100 million degrees Celsius. At these temperatures, the nuclei of hydrogen atoms can be fused, releasing a huge amount of energy.
But plasma is too hot to be contained by any material, so the plasma is suspended and held in place inside the tokamak by powerful magnetic fields. The heat from the fusion reaction can be used to generate steam, which in turn can power a turbine to create electricity.
The A.I. software that DeepMind is developing learns to control the magnetic fields that contain the plasma inside the tokamak. The system was able to manipulate the plasma into new configurations that can produce higher energy, but which physicists had been reluctant to attempt using previous control methods.
“This allows us to push things forward because we can take risks we would not dare take otherwise,” Ambrogio Fasoli, one of the Swiss Plasma Center scientists involved in the project, said. “Some of these [plasma] shapes that we are trying are taking us very close to the limits of the system, where the plasma might collapse and damage the system, and we would not risk that without the confidence of the A.I.”
It’s been a big two weeks for advances in fusion power. Two weeks ago, a group of European physicists working at the Joint European Torus Laboratory in England managed to create the most powerful controlled fusion power reaction in history. The experiment produced 59 megajoules of energy (the equivalent of about 11 megawatts of power) over a five-second reaction. That is twice the power of the previous record, set in 1997.
JET's tokamak is much larger and more powerful than the TCV tokamak used by the Swiss Plasma Center. That smaller tokamak can sustain a fusion reaction only for a maximum of two seconds, members of the Swiss research team said.
But similar methods to those used for the A.I. control algorithm at the Swiss Plasma Center might also be adaptable to larger, more powerful fusion reactors. The world’s largest such system is currently under construction in southern France, with support from a consortium of governments, including members of the European Union, U.S., China, and Russia.
Experts hope that fusion power will be developed enough to start powering portions of the world’s energy grid sometime in the second half of this century. Fusion offers the prospect of almost limitless energy from simple, relatively easy-to-source elements, and produces no greenhouse gases and relatively small amounts of radioactive waste that break down within about a century. Fission reactors, which are used in all existing nuclear power plants, on the other hand, produce large amounts of highly radioactive waste, some of which remains dangerous for tens of thousands of years.
The time frame in which nuclear fusion is likely to be commercially viable, however, is not fast enough for the technology to play much of a role in the current race to decarbonize the world’s energy sources and avert catastrophic global warming.
Pushmeet Kohli, who leads DeepMind’s efforts to use A.I. to address challenges in science, said that the fusion project showed that the research company is able to make fundamental impacts in physics. In late 2020, the company showed that an A.I. system it had created, called AlphaFold, could effectively predict the three-dimensional shape of a protein from its genetic sequence, a major breakthrough in biology that is likely to have far-reaching impacts on the field, including in the area of drug discovery. Previously, the company was best known for creating an A.I. system that could beat the world’s top players at the strategy game Go.
The A.I. system that DeepMind developed to manipulate the magnetic control system of the tokamak uses a method called reinforcement learning, in which the system learns by trial and error in a simulator. A concern with using this technique, however, is whether the simulator is good enough to allow the A.I. to effectively control a real tokamak. “We thought the simulation might not be good enough,” Jonas Buchli, a DeepMind researcher who worked on the project, said.
One issue is that the simulator did not accurately capture all of the variables present in a real tokamak. But Buchli said that by using a method where these factors were represented by random numbers in the simulation, DeepMind was still able to train an A.I. that was flexible enough to transfer its knowledge to the real tokamak.
Another issue is that in order to keep the plasma controlled inside the tokamak, the control algorithm must be able to make extremely fast decisions, executing adjustments to the magnet fields in just fractions of a second. Many A.I. systems take too long to make predictions to work in such a high-speed environment.
So the DeepMind team trained the A.I. system with two components. One is a large neural network, a type of A.I. designed loosely on how parts of the human brain function, that makes longer-term predictions about how changes to the magnetic field will shape the plasma. This network is then used to help train a much smaller system that learns the best way to implement the decisions that the first network recommends. But only the smaller network interacts directly with the tokamak control system because it has to be able to make decisions in less than 50 microseconds.