當前的潔淨技術無法實現預期的全球能源目標。也許能夠滿足預期需求缺口的唯一清潔、豐富的能源就是核融合。但我們要成功,需要大量的研發。在這集Podcast中,主持人將與Focused Energy共同創辦人Todd Ditmire共同探討核融合能源的現況與下一步挑戰。

時長: 28:42 | 發佈者: EE Times Taiwan | 發佈時間: 2022-09-22


Welcome to PowerUP, a podcast show hosted by Maurizio Di Paolo Emilio that brings life to some of the stories on power electronics technologies and products featured on PowerElectronicsNews.com and through other AspenCore Media publications. In this show, you’ll hear both engineers and executives discuss news, challenges, and opportunities for power electronics in markets such as automotive, industrial, and consumer. Here is your host, editor-in-chief of PowerElectronicsNews.com and EEWeb.com, Maurizio Di Paolo Emilio.

歡迎收聽由Maurizio Di Paolo Emilio主持的podcast節目Powerup。本節目為 PowerElectronicsNews.com 和其他 AspenCore Media 旗下網站的內容帶來活力。在本節目中,您將聽到工程師和高層討論電力電子和汽車、工業與消費性電子等市場的新聞、挑戰和商機。歡迎我們的主持人,Power Electronics NewsEEWeb.com主編Maurizio Di Paolo Emilio

MAURIZIO DI PAOLO EMILIO: Hello everyone, and welcome to this new episode of PowerUP. Today, we will talk about fusion energy and what’s next. Current renewable technologies cannot fulfill the increasing global energy needs in the longer term, but research and development can solve this problem and bring in the next energy revolution. Fusion energy and further advancements in renewable energy sources and energy storage technologies could help accelerate this research and development. They anticipate that the global energy goals cannot be met with current green technology. Perhaps the only clean, abundant energy source that can meet the anticipated demand gap is fusion. But for us to succeed, a lot of R&D is required. In this podcast with Todd Ditmire, co-founder of Focused Energy, we will discover the current situation and the next challenges for fusion energy. Todd serves as the company’s CTO as well as the director of the Center for High Energy Density Science and a professor of physics at the University of Texas at Austin, where he specializes in experimental studies of ultra-fast laser interactions with plasmas, atoms, and clusters. There are two approaches to fusion: magnetic and inertia confinement, with different variations of each. Focused Energy’s approach is laser-driven inertial confinement. But let’s talk with Todd. Hi, Todd. How are you?

MAURIZIO DI PAOLO EMILIO:大家好,歡迎收聽最新一集的PowerUP。今天,我們將討論核融合能源以及接下來會發生什麼。目前的可再生技術無法滿足全球日益增長的能源需求,但研發可以解決這個問題並帶來下一次能源革命。核融合能源以及可再生能源和儲能技術的進一步發展有助於加速這項研究和開發。他們預計當前的綠色技術無法實現全球能源目標。也許能夠滿足預期需求缺口的唯一清潔、豐富的能源就是核融合。但我們要成功,需要大量的研發。在本集邀請到Focused Energy共同創辦人Todd Ditmire 的Podcast中,我們將探索核融合能源的現狀和未來挑戰。Todd曾擔任公司的技術長、高能量密度科學中心主任和美國德州大學奧斯汀分校的物理學教授,專門研究超快雷射與電漿、原子和叢集的交互作用實驗性研究。核融合有兩種方法:磁約束和慣性約束,每種方法都有不同的變化。Focused Energy的方法是雷射驅動的慣性約束。但是讓我們和Todd談談。嗨,Todd。你好嗎?

TODD DITMIRE: Good morning, Maurizio. I’m great. It’s great to talk with you again.

TODD DITMIRE:Maurizio早安。我很好。很高興再次跟你談話。

MAURIZIO DI PAOLO EMILIO: My pleasure. Where are you located


TODD DITMIRE: Well, right now, I’m in the Isle of Skye in Scotland. I’m taking a little bit of a vacation, but I’m still happy to have a chance this morning to chat with you.

TODD DITMIRE:嗯,我現在在蘇格蘭的斯凱島。我正在休假,但我仍然很高興今天早上有機會跟你聊天。

MAURIZIO DI PAOLO EMILIO: Good, thank you. So before going into details about the topic of fusion energy, our community would like to get to know you a bit more. Can you tell us a bit about your back story? Tell us more about you.

MAURIZIO DI PAOLO EMILIO:太好了,謝謝。在詳細討論核融合能源這個話題之前,我們的社群想多了解你一些。你能告訴我們一些關於你的背景故事嗎?告訴我們更多關於你的資料。

TODD DITMIRE: Sure, I’d be happy to. So I’m an experimental physicist. I worked my entire career with high-power lasers and studying how those lasers interact with plasmas, how they heat plasmas, how the light interacts with those plasmas, and, in some of those experiments that I do, how that laser light can be used to spark fusion. I also have had a strong interest in the technology itself, the laser technology, and we’ll come to that. But anyway, I started my career in graduate school out at the University of California, Davis. I did my research at Lawrence Livermore National Laboratory, and Livermore is the U.S.’s biggest high-power laser lab. And when I went out there, I realized, what could possibly be cooler than high-power lasers? And I say this to this day, and I tell my students the same thing. So I did my Ph.D. thesis there, learning about high-peak-power lasers. And we’ll talk a little bit about that technology here in a bit. But when I finished my Ph.D. thesis, I went off to Imperial College in London, did more work with high-power lasers, then went back to Lawrence Livermore.

TODD DITMIRE:當然,我很樂意。我是一個實驗物理學家。我的整個職業生涯都在研究高功率雷射,研究這些雷射如何與電漿互動、它們如何加熱電漿、光如何與這些電漿交互作用,以及在我所做的一些實驗中,如何使用雷射引發核融合。我也對技術本身,雷射技術產生了濃厚的興趣,我們會談到這一點。但無論如何,我在加州大學戴維斯分校的研究所開始了我的職業生涯。我在勞倫斯利佛摩國家實驗室做研究,利佛摩是美國最大的高功率雷射實驗室。當我走出去時,我意識到,還有什麼比高功率雷射更酷的呢?直到今天我還是會這麼說,我也告訴我的學生同樣的事情。所以我完成了我的博士學位,我的論文題目是高峰值功率雷射。我們會稍微討論一下該技術。當我完成博士論文,我又去了倫敦帝國理工學院,用高功率雷射做了更多研究,然後又回到勞倫斯利佛摩。

And while I was at Livermore in the late ’90s, I had the opportunity to work with what was at the time the highest-power laser in the world, the first petawatt laser, and many of the results that took place at that time led to the technology that we’re using to harness fusion that we’ll talk about. While I was at Livermore, I also had another interesting opportunity: I met a very bright young German scientist named Marcus Roth. Marcus and I became lifelong colleagues and friends, and we ended up founding this company, Focused Energy, together. While Marcus was at Livermore with me, he did some pioneering experiments that led to results that are fundamental to the fusion approach that we’re pursuing, and we’ll talk about that.

90年代後期我在利佛摩時,有機會使用當時世界上功率最高的雷射──第一台拍瓦雷射器,以及當時發生的許多結果,導致到我們將要討論的、用於駕馭核融合的技術。當我在利佛摩時,我還有另一個有趣的機會:我遇到了一位非常聰明的年輕德國科學家Marcus Roth。 Marcus 和我成為一輩子的同事和朋友,我們最後共同創辦了Focused Energy這家公司。當Marcus和我一起在利佛摩時,他做了一些開創性的實驗,這些實驗產生了對我們正在追求的融合方法至關重要的結果,我們將討論這個問題。

Anyway, after I left Livermore, I went to the University of Texas to become a professor. There, I built a laser called the Texas Petawatt Laser, which for some years was the highest-power laser in the world, continued to do laser plasma experiments, built a center for energy density science, and continued to work with Marcus. Marcus would come over to do experiments. And then some years ago, I founded a company called National Energetics, where we were working to commercialize the high-power lasers that we use for research at the University of Texas. But to bring this part of a story to a close, a couple of years ago, just before Covid, Marcus Roth shows up at my house and says, “Todd, what do you think about joining a fusion startup company?” And I said, “That is the craziest idea I’ve ever heard. Tell me more.” And I was fascinated by what Marcus told me, and so I took leave from the university, packed my bags, and went to Germany. I worked with a fusion startup in Munich for six months and then went up to Darmstadt with Marcus and started Focused Energy. And that brings us to where we’re at now.

離開利佛摩後,我去了德州大學當教授。在那裡打造了一台名為Texas Petawatt Laser的雷射器,繼續進行雷射電漿實驗,該雷射多年來一直是世界上功率最高的雷射;並建立了能量密度科學中心,並繼續與Marcus合作。Marcus會過來做實驗。幾年前,我創辦了一家名為 National Energetics的公司,致力於將德州大學用於研究的高功率雷射商業化。作為這部分故事的結尾,幾年前,就在疫情之前,Marcus Roth出現在我家問我說:「Todd,你對加入一家核融合新創公司有什麼想法?」而我說:「這是我聽過的最瘋狂的想法,告訴我更多。」我被Marcus告訴我的事情迷住了,所以我從大學請假,收拾行裝去了德國。我跟位於慕尼黑的一個核融合新創團隊一起工作了六個月,然後和Marcus一起去了達姆施塔特,創辦了Focused Energy。這就是我們現在的情況。

MAURIZIO DI PAOLO EMILIO: And we will see in a bit Focused Energy. Before that, what’s fusion energy? There are a few approaches to fusion. What are these approaches? Maybe also if you can, mention some companies that are working in this field with advantages, and disadvantages for sure. So fusion energy has always seemed to be great in theory, in particular for the physicists, but difficult to accomplish in practice. So what makes this project more practical and achievable?

MAURIZIO DI PAOLO EMILIO:我們會談一些Focused Energy。在那之前,什麼是核融合能源?有幾種核融合方法,那些方法是什麼?如果可以,也許還可以提及一些該領域的其他公司,還有這些公司的優勢,當然還有劣勢。所以核融合能源在理論上似乎一直很好,特別是對物理學家來說,但要實踐卻很難。什麼能讓這個技術項目更實際以及可實現?

TODD DITMIRE: Well, yeah. So fusion, as most of you listening probably know, is the energy source that powers the visible universe. The sun and the stars are driven by fusion, and the essence of fusion is when two light elements come together and stick together. Now, this is a difficult process, because light elements are charged, and they repel each other, and opposites attract and likes repel. But if you can make a plasma, this means a gas that’s ionized, where the electrons are free of the atoms, hot enough, the energy of those particles can sometimes overcome that repulsion and stick together. And that’s what happens in the sun. In fact, it’s mostly just hydrogen atoms, protons that are sticking together and fusing, and through a series of reactions produce helium.

TODD DITMIRE:嗯,是的。正如你們大多數聽過的人可能知道的那樣,核融合是為可見宇宙提供動力的能源。太陽和星星是由核融合驅動的,而核融合的本質是兩個輕元素聚在一起並黏在一起。現在,那是一個艱難的過程,因為輕元素是帶電的,它們相互排斥,異性相吸,喜歡相斥。但是如果你可以製造電漿──這意味著一種離子化的氣體,其中電子沒有原子、夠熱,這些粒子的能量有時可以克服這種排斥並黏在一起。這就是在太陽裡發生的事情;事實上,大部分只是氫原子、質子黏在一起並融合,透過一系列反應產生氦氣。

Now it turns out, with light elements, as you go up the periodic table, when you fuse two elements together, the resulting element is ever so slightly lighter than the initial constituents. And the difference in mass is converted to energy, by Einstein’s famous formula, E = mc2. So that’s how fusion produces energy. Now, the sun has a huge amount of gravitational force to hold this ball of plasma together, so we can say that the sun is basically a gravitationally confined fusion reactor. We don’t have that advantage here on Earth if we’re going to harness this on Earth. So we have to take a couple of different approaches to harness fusion for energy production. Now, the sun uses protons. Most mainstream fusion approaches essentially use a little bit easier set of constituents or fuel, if you will, to fuse. Typically, we use two isotopes of hydrogen, which means a proton with additional neutrons. With one additional neutron, it’s deuterium. Turns out a very small fraction of the hydrogen in water is deuterium, so we can harvest deuterium literally from sea water.

事實證明,對於輕元素,當你看元素週期表的上半部,當你將兩個元素融合在一起時,得到的元素比初始成分要輕得多。利用愛因斯坦著名的公式E = mc2,質量差轉化為能量,這就是核融合產生能量的方式。現在,太陽有巨大的引力把這個電漿球黏在一起,所以我們可以說太陽基本上是一個引力受限的核融合反應爐。但如果我們要在地球上利用它,地球就沒有這種優勢。因此,我們必須採取幾種不同的方法來利用核融合產生能源。太陽是使用質子,而大多數主流融合方法本質上是使用更簡單的成分或燃料來融合。通常,我們使用氫的兩種同位素,這意味著一個帶有額外中子的質子。再加上一個中子,就是氘。水中的氫有一小部份是氘(重氫),所以我們可以從海水採集氘。

Tritium is a little harder to come by. That’s two neutrons, but we can make tritium it turns out if we have a neutron and we slam it into a lithium atom, and lithium, we can mine. So essentially, if we can get fusion to work with deuterium and tritium, it works at a much lower temperature than protons, and we can make the fuel very simply. So the mainstream approaches to fusion are fusing deuterium and tritium. When those two fuse, they produce two particles, a helium atom, or a helium nucleus, and a neutron. Now these are both good things for us, and all the approaches to fusion usually harness these in some way or the other. The helium atom is charged, and it bangs into other neighboring ions. It heats them up and causes additional fusion reactions to occur. So if we can produce conditions where we hold those so-called alpha particles in, we can get this fusion plasma to burn. And that’s part of the holy grail of fusion is to get a burning plasma or ignition, if you will.


The other particle is a neutron. That neutron flies out. It’s neutrally charged, and it does two things. We get a double whammy with the neutron. First of all, it carries energy and therefore heats up material, which we can then use to make steam and harness for electrical energy. But the neutron can also slam into a lithium atom and produce that tritium that we need.


Now, there’s a couple of main approaches to making this work, two of them quite different, although they have some commonalities. But one, and probably the most common approach, is to make a plasma that’s low-density, about a thousandth of a percent of atmospheric density, and hold that plasma in with magnets. And there are a couple of different configurations. Probably the most common is to make the magnets in the shape of a donut, a so-called tokamak, and probably the leading company, the private company in fusion, is pursuing this approach. Commonwealth Fusion in Massachusetts is a really class act, and a lot of really bright physicists, and they’re pursuing this so-called magnetic confinement fusion using tokamak.

現在,有幾種主要的方法可以完成這項工作,其中兩種方法截然不同,儘管它們有一些共同點。但是,一種可能也是最常見的方法是製造一種低密度的電漿,大約是大氣密度的千分之一,然後用磁鐵將電漿保持在其中。並且有幾種不同的配置。可能最常見的是將磁體製成甜甜圈形狀,即所謂的托卡馬克,而且一些領先企業、即融合領域的私人公司,正在採用這種方法。麻州的Commonwealth Fusion十分出眾,有很多非常聰明的物理學家,他們正在使用托卡馬克進行這種所謂的磁約束核融合。

There are other configurations, so for example, there’s a company out in California called TAE that has a different configuration. But this approach has seen a lot of advances in recent years. And in fact, a world record was set at a tokamak in England some years back, where they produced about 67% of the energy out by fusion as energy that went in. Almost what we call break even, tantalizingly close. And Commonwealth Fusion has some new technology that they’re developing to miniaturize tokamak, very interesting and exciting

還有其他配置,例如,加州有一家名為TAE的公司擁有一種不同的配置,但其方法近年來取得了很大進展。事實上,幾年前英國的托卡馬克裝置創造了一項世界紀錄,在那裡他們透過核融合產生的能量,大約是67%的輸入能量,幾乎達到我們所說的收支平衡,非常接近。 Commonwealth Fusion有一些新技術,他們正在開發微型化托卡馬克,非常有趣和令人興奮。

Now the other approach is something quite different, and it’s something that’s been pursued largely at Lawrence Livermore National Laboratory, and that’s of course where I and Marcus grew up. So this approach is so-called inertial confinement fusion. In other words, make plasma conditions at very high density and high temperature, and create conditions such that that alpha heating and burn can happen so quickly that the plasma burns up before it can explode. And essentially, we say the plasma’s confined by its own inertia, so-called inertial confinement, or in the community, we typically call this from the standpoint of energy production inertial fusion energy, or IFE. So you’ll hear the term IFE a lot in the chatter about fusion.


Now, there are a few approaches to IFE. The approach that we’re pursuing and the approach that Livermore has pursued, although with a slightly different flavor, is to use large lasers, to start with a pellet of that deuterium and tritium I told you about, and irradiate the surface of this pellet. Now, that makes the surface hot. It expands and acts like a rocket engine, and now you have a bunch of rocket engines imploding the remaining DT fuel. Now if you get the conditions right, you can get that fuel hot enough and dense enough. And here, dense enough means hundreds of grams per CC, so hundreds of times solid density, so a much, much different density regime than magnetic confinement, and get that fusion fuel to burn.

現在,有幾種 IFE 方法。我們追求的方法和利佛摩追求的方法,雖然風格略有不同,但使用大型雷射,從我告訴你的氘和氚顆粒開始,然後照射這個顆粒的表面,使表面變熱,並像火箭引擎一樣膨脹並發揮作用,現在你有一堆火箭引擎內爆剩餘的DT燃料。如果條件正確,就可以使燃料足夠熱且密度足夠──在這裡,足夠密集意味著每CC數百克,是固體密度的數百倍,與磁約束相比,密度狀態有很大不同,並能讓核融合燃料燃燒。

Now, there are some flavors with this approach. I won’t go into all of them. I will just mention a couple. So Lawrence Livermore, using their big national ignition facility, set a world record back in August, in which they used lasers to the inside of a can that made X-rays and imploded a shell and they produced a gain of 0.7. They got 1.3 megajoules of fusion energy out with 1.9 megajoules of energy in it. This result has electrified the community. This shows that we are tantalizingly close to a gain above 1, which is what we need for energy production. The other approach is one where you shoot the lasers directly onto the pellet, and this is so-called direct drive, and this is the approach that we’re pursuing.

這種方法也有一些不同的類型,我不會全部介紹,只提其中幾個。勞倫斯利佛摩使用他們的大型國家點火設施在8月就創造一項世界紀錄,他們在一個罐子內使用雷射製造X光並內爆一個殼,產生了0.7的增益,他們得到了1.3兆焦耳的核融合能量,其中包含 1.9 兆焦耳的能量。這一結果讓社群興奮不已,代表我們非常接近1以上的增益,這是我們生產能源所需要的。另一種方法是將雷射直接射到顆粒上,這就是所謂的直接驅動,也是我們正在追求的方法。

MAURIZIO DI PAOLO EMILIO: So your approach, Focused Energy’s approach, your company, is laser-driven inertial confinement. So in terms of your company, your approach, what are the current limitations now in technology? How could this research prove crucial in revolutionizing its future? But just in terms of fusion, when will we know if fusion is going to work?

MAURIZIO DI PAOLO EMILIO:所以你的方法,你的公司Focused Energy的方法,是雷射驅動的慣性約束。那麼就你的公司、你的方法而言,目前技術上的限制是什麼?這項研究如何證明對於徹底改變其未來至關重要?但就核融合而言,我們什麼時候才能知道核融合可行?

TODD DITMIRE: OK, good question. But before we go to that, so let’s talk a little bit about our approach. So the main approach that Livermore and the big laboratory at the University of Rochester pursue is to implode this capsule with these lasers, and to get it to heat up by the actual compressions. So it works kind of like a diesel engine works. You shoot fuel into the cylinder and you compress it with the piston and you get it to combust. But Marcus and I were at Livermore. Marcus did some pioneering experiments with a whole group of people at Livermore. And they showed that with these petawatt lasers, you can accelerate protons to very high energies.

TODD DITMIRE:好的,好問題。但在我們開始之前,讓我們先談談我們的方法。因此,利佛摩和羅徹斯特大學的大實驗室追求的主要方法,是用雷射讓那個膠囊內爆,並透過實際的壓縮使其升溫。所以它的運作方式有點像柴油引擎,你將燃料噴射到汽缸中,然後用活塞壓縮它,然後讓它燃燒。但Marcus和我待過利佛摩,Marcus在利佛摩與一群人進行了一些開創性的實驗;他們證明,使用那些拍瓦雷射,可以將質子加速到非常高的能量。

Now, these lasers are very short in time duration, and we make these lasers using a technology called chirped pulse amplification, which is actually the technology that led to the 2018 Nobel Prize in physics for Gérard Mourou and Donna Strickland. And with this technology, it’s now possible to produce laser pulses that are as short as a picosecond, 10–12 seconds, or even shorter. That means their intensity, their energy per time, because the time is so short, is very high. And what Marcus and collaborators found at Livermore was that if you focused one of these petawatt lasers onto a foil, they accelerate electrons to very high energy, and then the electrons pull the protons behind them and they get a nice directed gun of protons.

現在,這些雷射器持續時間非常短,我們使用稱為啁啾脈衝放大器的技術製造這些雷射器,這實際上是讓Gérard Mourou和Donna Strickland獲得2018年諾貝爾物理學獎的技術;借助這項技術,現在可以產生短至1皮秒、10-12秒甚至更短的雷射脈衝,這意味著其強度、每次的能量,因為時間很短,非常高。Marcus和他的合作夥伴在利佛摩發現的是,如果你將這些拍瓦雷射器中聚焦到金屬薄片上,它們會將電子加速到非常高的能量,然後電子將質子拉到它們背後,它們就會得到一個很好的定向質子槍。

And so the idea that Marcus pioneered was to say, look, let’s take that beam of protons and use it as a spark plug to initiate the ignition in this compressed fusion fuel. So this has pluses and minuses over the so-called typical hotspot ignition that Livermore pursues. It does make the compression easier. We don’t have to compress as fast and as hard, and we don’t have to be as symmetric. Now on the other hand, we had this complication of having to produce the protons, but we believe that the experiments that have been done show that the number of protons we can get to ignite fuel is high enough.


And so one of the challenges, you ask, you know, what are the limitations in the technologies, and what’s going to be crucial, is going to be putting together in one machine a laser large enough to compress the fuel, much like the National Ignition Facility at Livermore, combined with these petawatt lasers to produce the proton spark plug to ignite. This approach is called proton fast ignition. And this is the approach that we’re pursuing at Focused Energy. We believe that this is the most likely approach to get us to high gain. High gain means we need to get 100× more fusion energy out than laser energy we put in. That’s just purely so that we don’t suck up all the energy by sucking electricity into our laser.

所以你問我挑戰之一是什麼?技術的限制是什麼?什麼是至關重要的?是在一台機器中組裝一個足夠大的雷射來壓縮燃料,就像利佛摩的點火設施與這些拍瓦雷射相結合,生產質子火星塞以點燃。這種方法稱為質子快點火,也就是我們在Focused Energy追求的方法。我們相信這是最有可能讓我們獲得高增益的方法。高增益意味著我們需要獲得比我們投入的雷射能量多100倍的核融合能量,這純粹是為了我們不會是透過將電力吸入雷射來取得所有能量。

Now, that’s a physics challenge. Because of the NIF result, we think we’ve made huge progress toward that. Our company’s principal goal is to build by the end of a decade the laser that I just described, which is the laser that both compresses and produces the petawatt beams to produce the protons. In our case, the laser will be with the nanosecond means to compress something like 400 kilojoules with green light, and then the big daddy is 150 kilojoules of picosecond pulses.


Now, where the technology is at now, we can now produce something like two kilojoules of picosecond pulses in a single beam. And so part of the technology challenge is going to be building multiple beams together in an affordable way to be able to produce the proton beam that we need for ignition. But we think that there’s enough physics that has been done to show we can get it there. We think we can get it there by the end of the decade. And laser technology, some of which I developed in Austin with my company, National Energetics, exists to build such a laser with a high enough rep rate that we can make the progress on the timescale that’s going to be relevant for energy production and to help solve climate change.

就目前的技術而言,我們現在可以在單光束中產生大約2千焦耳的皮秒脈衝。因此,技術挑戰的一部分是以經濟實惠的方式將多個光束構建在一起,以便能夠產生我們點火所需的質子束。但是我們認為已經完成了足夠多的物理學研究來證明我們可以做到這一點,我們認為我們可以在這十年內實現它。而雷射技術,其中一些是我在奧斯汀分校跟我的公司National Energetics開發的,後者的存在是為了打造這樣具備足夠高重複率的雷射,我們可以在與能源生產相關的時間尺度上取得進展,並幫助解決氣候變遷問題。

Now, the last question you asked was, when will we know if fusion is going to work? And my answer, my flip answer to that is, well, we already know fusion works. I mean, we have now the physics results that show fusion works, such as the JET result in Britain. So I would change this question to make it a little more subtle is, when will we know whether we can get a high enough gain with the fusion approaches that we know have been shown to work to be viable for energy production? And that’s a more subtle and interesting question, and that’s going to require the development of these big machines, such as the tokamak that Commonwealth is building, such as the laser that we are planning to build. So to see whether we can get high enough gain to make fusion work for energy.

現你問的最後一個問題是,我們什麼時候才能知道核融合可行?我的回答──輕率的回答──是,我們已經知道核融合是可行的。我的意思是,我們現在有顯示核融合可行的物理結果,例如英國的JET結果。所以我會修改這個問題讓它更微妙一點:我們何時才能知道我們是否可以透過我們已知的核融合方法取得足夠高的增益,而且這些方法已經證明對能源生產是可行的?這是一個更加微妙和有趣的問題,這將需要開發那些大型機器,例如Commonwealth Fusion正在製造的托卡馬克,例如我們計劃打造的雷射。因此,看看我們是否可以獲得足夠高的增益,以讓核融合能用於能源。

MAURIZIO DI PAOLO EMILIO: So your main research and way focuses on lasers. And there are implications in other fields such as optics, telecommunication, etc. What are these implications in other infrastructures, markets?

MAURIZIO DI PAOLO EMILIO:所以你的主要研究和方式集中在雷射上。這在光學、電信等其他領域也有影響,這些對其他領域的基礎設施、市場有什麼影響?

TODD DITMIRE: Yeah, that’s a great question. So lasers have been shown to have applications everywhere, right? That’s what I love about lasers: They’re everywhere, from scanners to making fusion work. So part of making fusion work with inertial fusion energy is we have to build high-energy lasers, but we need to make them compact, we need to make them manufacturable, and we need to make them manufacturable. An ultimate fusion power plant operating on this approach would have to run at something like 10 hertz, but we’re basically making little fusion explosions, ——–. It also means we need a laser that fires at that rep rate.

TODD DITMIRE是的,這是一個很好的問題。所以雷射已被證明在任何地方都有應用,對吧?這就是我喜歡雷射的原因:它們無處不在,從掃描器到讓核融合運作。因此,利用慣性核融合能量進行核融合的一部分,是我們必須製造高能量雷射,但我們需要讓它們外型小巧,我們需要讓它們是負擔得起的,我們需要使它們可製造。以這種方式運作的終極核融合發電廠必須以10Hz左右的頻率運作,但我們基本上只是在製造很少的核融合爆炸──這意味著我們需要一個以該重複率發射的雷射。

Now, if we have such a laser, a compact laser that’s manufacturable, one very interesting possible spinoff that Marcus and I and others have been working on for some years is to use these lasers to produce unique sources of radiation, meaning X-ray photons, protons, electrons, neutrons, or even muons. And these radiation sources could be used in all kinds of technological applications.


So I’ll give you a couple of examples. If we have one of these rep-rated lasers firing into targets like Marcus has pioneered, we can produce a large number of neutrons. And neutrons are used, typically, people go to a small research reactor and take their source to study materials or to look for defects in cracks or turbine blades. For example, a U.S. Air Force–operated reactor for some time to look for cracks in aircraft parts. That case, they had to bring the mountain to the source. Wouldn’t it be wonderful if we had a mobile source where we could bring the source to the mountain? Bring the source to the airplane and look for cracks and defects. One of the things that neutrons can look for is moisture in structural components in bridges, and can we look to see if there’s corrosion in bridges and determine whether the bridge needs to be rebuilt or torn apart. So this is actually a pressing problem, and a neutron source that’s mobile just really doesn’t exist.


The other interesting application that I’m particularly excited about is that with these lasers, you can produce high-energy electrons. I don’t know if you remember I mentioned that the first step to producing the protons was to produce a bunch of high-energy electrons by these intense lasers. Those electrons can also be used, you can shine them into something that’s high on the periodic table, like tantalum or gold, and produce beams of muons. So muons are actually cosmic rays. We get bombarded by muons all the time. One goes through my hand every second. Muons are essentially heavy, they’re like heavy electrons, and they go through a lot of material. And so people have talked about using muons to look for tunnels underground, to study the insides of pyramids, or to use muons to look for high-Z materials like plutonium that the bad guys might want to move around. And so one possible application would be to build a compact source of muons using these lasers that would be transportable that could be used to radiograph components coming into a port in the U.S. We have many problems and concerns about this, to look for elicit materials and essentially protect ports and commerce.


MAURIZIO DI PAOLO EMILIO: So my last one, my last comment, my last consideration for fusion in terms of investment. So innovations in fusion mean that it could soon be used as a carbon-free source of energy to decarbonize the electrical grid. We need to have a lot of investments. Investments are needed to support fusion technology on its path to commercialization. So are there enough investors interested in this technology to keep research moving forward? Or will government support be needed? What do you think? What are the major challenges that stand in the way of industrial and commercial fusion?

MAURIZIO DI PAOLO EMILIO:我的最後一個問題,最後一個在核融合投資方面的考量是,核融合領域的創新意味著它可以很快被當作無碳能源,讓電網脫碳。我們需要大量的投資。需要投資來支持核融合技術走向商業化,那麼是否有足夠多的投資者對這項技術感興趣,以推動研究向前發展?還是需要政府支持?你怎麼看?阻礙工商業應用核融合的主要挑戰是什麼?

TODD DITMIRE: Well, one of the things that’s been exciting for me, and I’m somebody as an academic for 20 years, I did my research funded on government grants and funds, and I understand the challenges of capturing government’s funding money for science. One of the things that’s just been exciting over the last couple of years is the incredible amount of investor interest in fusion, and the realization among private investors that fusion is almost certainly going to have to be a solution to our energy future. I mean, everybody understands that we’re going to need something like 50 trillion watts of power by 2050, and that it’s just not going to be possible with the traditional renewables: wind, solar, hydro. We’re going to need a different source, and investors understand this.

TODD DITMIRE:嗯…讓我感到興奮的事情之一,是身為在學界20年的人,我在政府贊助之下進行了研究,我了解取得政府資助科研資金的挑戰姓。在過去的幾年,令人興奮的一件事是投資者對核融合的極大興趣,私人投資者意識到核融合幾乎絕對會成為我們未來能源的一個解決方案。我的意思是,每個人都明白,到 2050 年,我們將需要大約 50兆瓦的電力,而只用傳統的可再生能源:風能、太陽能、水力發電是不可能的。我們會需要一個不同的能源,投資者明白這一點。

So to date, there’s been something like, and the number changes all the time, but there’s been something like $4 billion of private investment money that has gone into the various fusion companies. Commonwealth Fusion, one of the leaders in this field, have raised up to $1.8 billion. This is a very exciting development. So investor interest to make this work is there.

所以到目前為止,一直是類似的狀況,而且數字一直在變化──有大約40億美元的私人投資進入了各種核融合公司。作為該領域的領導者之一,Commonwealth Fusion 已募集了高達18 億美元的資金。這是一個非常令人興奮的發展,展現投資者讓核融合可行的興趣。

I will say though, we do have huge challenges, because to get fusion to work, as I’ve mentioned earlier, we have to build big machines. And big machines means multi-billion-dollar machines. The laser that we’re talking about and planning to build and design right now is approximately a $3 billion piece of hardware. So how do we get there? Well, the answer probably is going to be partnerships between the public and private sector. And we’re seeing this happen. In fact, the U.S. has been very forward-looking. The U.S. Congress has been very forward-looking, and it’s been amazing the number of members, actually both Republicans and Democrats have seen this and have supported funding at the Department of Energy to fund public-private partnerships in fusion energy research.


And so I think what you’re going to see over the course of the remaining part of the decade is going to be significant investments through the public sector in partnership, basically leveraging investment money, to the tune of billions, because that’s what we’re going to need to build these big tokamak and these big lasers and these big machines, to build a pilot power plant. I think that’s going to happen. There’s the interest and will in the government, at least in the U.S., and I think we’re seeing this also in Europe starting to grow, combined with the already-existing investor interest. I think it’s going to make that happen. And so I’m very excited. I tell people, if you asked me 10 years ago, would you start a fusion startup company, I would have said that is the dumbest idea I’ve ever heard. You know, please go away. Well, it’s not a dumb idea anymore. The technology is there. the investment money is there. The government support is now growing to be there. It’s a pretty exciting time.


MAURIZIO DI PAOLO EMILIO: Yeah, I agree. So Todd, we are in conclusion. Thanks a lot. Thanks a lot for being on this PowerUP podcast and to share with us a lot of information about fusion. Thank you, Todd.

MAURIZIO DI PAOLO EMILIO是的,我同意。所以Todd,我們也得出結論。非常感謝,非常感謝你參與這次的PowerUP Podcast與我們分享很多關於核融合的資訊,謝謝你,Todd

TODD DITMIRE: Thanks, Maurizio. It’s a real pleasure to talk with you.

TODD DITMIRE:謝謝Maurizio,很高興能跟你談話。

MAURIZIO DI PAOLO EMILIO: Thank you, Todd. So the fusion of two atoms, power of our sun and the stars of the universe, engineers and scientists have been working for the case to achieve control of the fusion on Earth to run a power plant using the magnets and lasers to create the necessary conditions, because nuclear fusion wouldn’t produce harmful, long-lived, radioactive waste or the greenhouse gases that drive climate change. It would be a good source of energy.

MAURIZIO DI PAOLO EMILIO:謝謝Todd。所以兩個原子的核融合,我們的太陽和宇宙恆星的能量,工程師和科學家們一直在努力為實現控制地球上的核融合,使用磁鐵和雷射來打造讓發電廠運作的必要條件,而因為核融合不會產生有害的、長期存在的放射性廢物,或排放導致氣候變化的溫室氣體,這會是一個很好的能源。

A nanosecond-long pulse from a laser similar to National Ignition Facility is used to compress the deuterium–tritium fuel in the Focused Energy method for inertial fusion energy. A picosecond beam from a second petawatt laser would then strike a thin, 1-?m–thick spherical foil, igniting the compressed fuel, much like the spark plug in a gasoline engine. Ballistically focusing the energy on the fuel, the protons would accelerate. The inventors think that the high-intensity femtosecond to picosecond pulses of these petawatt lasers will enable them to outperform National Ignition Facility to start fusion processes that produce many times the energy required to start them.

類似於美國國家點火設施的雷射發出之奈秒長度脈衝,以Focused Energy採用的慣性核融合能源方法壓縮氘-氚燃料。然後,來自第二個拍瓦雷射的皮秒光束會撞擊1微米厚的薄球形金屬薄片,點燃壓縮燃料,就像燃油引擎中的火星塞,能將能量彈道集中在燃料上,質子會加速。發明人認為,這些拍瓦雷射的高強度飛秒到皮秒脈衝,將使它們能夠在啟動核融合過程方面之表現優於國家點火設施,而核融合過程產生的能源能達到比啟動它們所需能源的數倍。

As Todd said, the company’s principal goal is to build by the end of the decade the laser that both compresses and produces, so the petawatt beams to produce protons in our case. He said it’s going to be putting together in one machine, to produce the proton sparkplug the proton fast ignition.


Focused Energy’s path to laser fusion also creates the opportunity to develop near-term laser-driven radiation sources to solve critical inspection problems in several infrastructures.

Focused Energy 的雷射核融合之路,還創造了在近期開發雷射驅動放射源的機會,以因應多種基礎設施所需的嚴格檢查。

The technology is there. The investment money’s there that the government support is now growing to be there. It’s a pretty exciting time, as Todd concluded.



參考原文:Fusion Energy: What’s next?