S*******l
发帖数: 4637 | 1 commonwealth fusion system
https://cfs.energy/
华尔街日报昨天报道刚融到18亿美刀，有啤酒瓶子什么的。
https://eapsweb.mit.edu/news/2018/new-approach-fusion-energy
看了下是用高温超导磁体的托克马克装置，据说实现了能量正输出。
大牛们来批判一下，是不是核聚变发电实现在即。
这公司要上市那就是宇宙第一牛公司了。 |
s*x
发帖数: 8041 | |
g***n
发帖数: 14250 | |
k****r
发帖数: 421 | |
n********g
发帖数: 6504 | 5 物理民科，没看你的新闻。
1、只听说MIT弄了块磁铁，没听说搞了驼马。
2、核聚变即使成功，也比烧煤贵，和光伏比成本差数量级。
3、所以，宇宙第一牛还是能去宇宙并防御地球的SpaceX。
【在 S*******l 的大作中提到】
: commonwealth fusion system
: https://cfs.energy/
: 华尔街日报昨天报道刚融到18亿美刀，有啤酒瓶子什么的。
: https://eapsweb.mit.edu/news/2018/new-approach-fusion-energy
: 看了下是用高温超导磁体的托克马克装置，据说实现了能量正输出。
: 大牛们来批判一下，是不是核聚变发电实现在即。
: 这公司要上市那就是宇宙第一牛公司了。
|
k**********4
发帖数: 16092 | 6 我问了一个美国国家实验室搞核巨变的人，他说没戏
【在 S*******l 的大作中提到】
: commonwealth fusion system
: https://cfs.energy/
: 华尔街日报昨天报道刚融到18亿美刀，有啤酒瓶子什么的。
: https://eapsweb.mit.edu/news/2018/new-approach-fusion-energy
: 看了下是用高温超导磁体的托克马克装置，据说实现了能量正输出。
: 大牛们来批判一下，是不是核聚变发电实现在即。
: 这公司要上市那就是宇宙第一牛公司了。
|
V*******n
发帖数: 1 | |
S*******l
发帖数: 4637 | 8 https://www.psfc.mit.edu/sparc
这是他们的托克马克装置。
【在 n********g 的大作中提到】
: 物理民科，没看你的新闻。
: 1、只听说MIT弄了块磁铁，没听说搞了驼马。
: 2、核聚变即使成功，也比烧煤贵，和光伏比成本差数量级。
: 3、所以，宇宙第一牛还是能去宇宙并防御地球的SpaceX。
|
n********g
发帖数: 6504 | 9 热点核聚变方向类似于对撞机。
驼马不吃香。越来越纯骗房顶。
【在 k**********4 的大作中提到】
: 我问了一个美国国家实验室搞核巨变的人，他说没戏
|
S*******l
发帖数: 4637 | 10 https://tae.com/fusion-power/
另外一家公司，不是托克马克，是加速器聚变装置，对撞聚变材料，中性粒子流稳定等
离子体，直到聚变发生
和托克马克比，哪个有希望？ |
n********g
发帖数: 6504 | 11 PPT，= 0
【在 S*******l 的大作中提到】
: https://www.psfc.mit.edu/sparc
: 这是他们的托克马克装置。
|
s*x
发帖数: 8041 | 12 合肥稳态强磁场2018年都已经40多特斯拉了，这个MIT吹了半天什么高温超导，什么首
次，什么第一，最后一看只有20T
【在 S*******l 的大作中提到】
: https://www.psfc.mit.edu/sparc
: 这是他们的托克马克装置。
|
n********g
发帖数: 6504 | 13 也可能合肥牛皮吹破了 — 路过吃瓜民科
【在 s*x 的大作中提到】
: 合肥稳态强磁场2018年都已经40多特斯拉了，这个MIT吹了半天什么高温超导，什么首
: 次，什么第一，最后一看只有20T
|
s*x
发帖数: 8041 | 14 也可能合肥达到了200特斯拉，但为了隐藏实力，只报导40T
【在 n********g 的大作中提到】
: 也可能合肥牛皮吹破了 — 路过吃瓜民科
|
S*******l
发帖数: 4637 | 15 那还能忽悠到那么多钱？
【在 s*x 的大作中提到】
: 合肥稳态强磁场2018年都已经40多特斯拉了，这个MIT吹了半天什么高温超导，什么首
: 次，什么第一，最后一看只有20T
|
n********g
发帖数: 6504 | 16 MIT虽然很多也不靠谱。好歹人家不自称美国的清华。
【在 s*x 的大作中提到】
: 也可能合肥达到了200特斯拉，但为了隐藏实力，只报导40T
|
n********g
发帖数: 6504 | 17 所以SpaceX绝壁不会破产。美国钱多无聊的太多。
【在 S*******l 的大作中提到】
: 那还能忽悠到那么多钱？
|
C*****l
发帖数: 1 | 18 别瞎说，EAST磁场3.5T，这个公司估计顶多能做到10T。
【在 s*x 的大作中提到】
: 合肥稳态强磁场2018年都已经40多特斯拉了，这个MIT吹了半天什么高温超导，什么首
: 次，什么第一，最后一看只有20T
|
s*x
发帖数: 8041 | 19 不是east，是专门验证稳态磁场的，42T。现在在建的应该更高。MIT这个是号称20T
【在 C*****l 的大作中提到】
: 别瞎说，EAST磁场3.5T，这个公司估计顶多能做到10T。
|
C*****l
发帖数: 1 | 20 尼玛，高磁场纪录早就有了，冲击世界纪录的那种线圈只有几厘米的直径，能放大到几
米大小么？
【在 s*x 的大作中提到】
: 不是east，是专门验证稳态磁场的，42T。现在在建的应该更高。MIT这个是号称20T
|
n********g
发帖数: 6504 | 21 能比紫光牛逼不
【在 k****r 的大作中提到】
: 一次就融1.8个逼，确实牛
|
s*x
发帖数: 8041 | 22 MIT这个就是专门针对聚变的，合肥那个不是。但是没看出来MIT这个有如何惊人的地方
，除非有啥石破天惊的新超导材料，否则都是工程问题。
【在 C*****l 的大作中提到】
: 尼玛，高磁场纪录早就有了，冲击世界纪录的那种线圈只有几厘米的直径，能放大到几
: 米大小么？
|
n********g
发帖数: 6504 | 23 工程也石破天惊。MIT擅长的是工程，不是灌水。
【在 s*x 的大作中提到】
: MIT这个就是专门针对聚变的，合肥那个不是。但是没看出来MIT这个有如何惊人的地方
: ，除非有啥石破天惊的新超导材料，否则都是工程问题。
|
s*x
发帖数: 8041 | 24 没看出来哪儿石破天惊
【在 n********g 的大作中提到】
: 工程也石破天惊。MIT擅长的是工程，不是灌水。
|
f********g
发帖数: 32 | 25 那个核心上千万度的高温，没有特殊的材料，根本约束不住。
聚变，可能还要再等 50年。
【在 k**********4 的大作中提到】
: 我问了一个美国国家实验室搞核巨变的人，他说没戏
|
f****i
发帖数: 1 | 26 搞笑
iter目标磁场才12T
你知道40T是什么概念么？
【在 s*x 的大作中提到】
: 合肥稳态强磁场2018年都已经40多特斯拉了，这个MIT吹了半天什么高温超导，什么首
: 次，什么第一，最后一看只有20T
|
C*****l
发帖数: 1 | 27 如果真能稳定在20T，还能达到米级别的大小，那说不定有一点戏可以看
【在 s*x 的大作中提到】
: MIT这个就是专门针对聚变的，合肥那个不是。但是没看出来MIT这个有如何惊人的地方
: ，除非有啥石破天惊的新超导材料，否则都是工程问题。
|
f****i
发帖数: 1 | 28 搞笑，
周围都是真空，DT核聚变又不产生photon,主要是防止中子损伤而不是热损伤
【在 f********g 的大作中提到】
: 那个核心上千万度的高温，没有特殊的材料，根本约束不住。
: 聚变，可能还要再等 50年。
|
S*******l
发帖数: 4637 | 29 Building a better bagel magnet
Commonwealth Fusion Systems took different approach.
"You basically have to put a sun in a bottle," says Mumgaard, "It turns out,
if you build a magnetic bottle that can actually hold the fuel at the same
conditions stars get to, you can create and sustain fusion."
The philosophy at Commonwealth Fusion Systems is that, by building a smaller
device, they can make commercially fusion plants sooner and cheaper. SPARC
will be just 1/40th the size ITER.
The critical component MIT and Commonwealth Fusion built was the world’s
most powerful superconducting magnet. It's encased in a stainless steel
vacuum chamber, surrounded by tanks of liquid nitrogen.
"Buried inside there," says Mumgaard, "is a magnet that’s 10 tons, about 10
feet tall and it has the distinction of being made out of a material that
allows it to go to a very high magnetic field."
The material is called high temperature superconducting wire. Actually, it's
flat like a ribbon and the company is the largest buyer of the material in
the world.
In a recent test, the new magnet was 400,000 times stronger than the earth’
s magnetic field. Seven peer-reviewed research papers found if you could
build magnets this powerful, it should be possible to build a working
tokamak that produces net energy.
When you're hot you're hot. When you're not you're not.
"So the magnets will operate at 20 kelvin, roughly minus 400 degrees
Fahrenheit," says Joy Dunn, head of operations for the company. That's
relatively warm by superconducting standards. At this temperature the
superconducting wires lose all resistance to the flow of electrons. This
enables the magnets to compress the plasma to superhot temperatures and
pressure, creating the conditions to make fusion energy inside the tokama. |
f****i
发帖数: 1 | 30 就像羊82建议包帝不搞加速器一样，
美帝理论界从80年代开始就认为托克马克没有希望，纯粹浪费时间，不建议搞
所以美帝退出托克马克整整4个decade了
这次mit只不过是补课而已，当然为了骗钱，为了吸引牛和娘这类有钱屁民的眼球，就
要放个火箭
这次美帝放的火箭是你们都他妈没有的超强磁场 |
S*******l
发帖数: 4637 | 31 说因为他们的超导磁铁世界最强，可以做到只有ITER的1/40体积。
超导磁体工作温度是20K.
磁铁强度是地磁40万倍（是不是记者写错了？） |
f********g
发帖数: 32 | 32 这个俺确实不懂，确实得服
【在 f****i 的大作中提到】
: 搞笑，
: 周围都是真空，DT核聚变又不产生photon,主要是防止中子损伤而不是热损伤
|
f***n
发帖数: 4682 | 33 这个是不是就是几年前宣布五年内做出小型化核聚变装置的那个
【在 S*******l 的大作中提到】
: commonwealth fusion system
: https://cfs.energy/
: 华尔街日报昨天报道刚融到18亿美刀，有啤酒瓶子什么的。
: https://eapsweb.mit.edu/news/2018/new-approach-fusion-energy
: 看了下是用高温超导磁体的托克马克装置，据说实现了能量正输出。
: 大牛们来批判一下，是不是核聚变发电实现在即。
: 这公司要上市那就是宇宙第一牛公司了。
|
f****i
发帖数: 1 | 34 托克马克对于美帝，就像加速器对于中帝一样
中帝有羊82，美帝也有羊92，美帝的羊92早在4个decade前就建议美帝退出毫无希望的
托克马克研究，
所以安了，这次美帝只是补课而已，所谓超强磁场，纯粹为了骗钱 |
S*******l
发帖数: 4637 | 35 根据地磁强度，他们这个磁铁强度范围是10-26T,看来没写错 |
S*******l
发帖数: 4637 | 36 对
【在 f***n 的大作中提到】
: 这个是不是就是几年前宣布五年内做出小型化核聚变装置的那个
|
n********g
发帖数: 6504 | 37 那个好像是GE
Starship都要上天了
东海岸的没一个好东西
【在 f***n 的大作中提到】
: 这个是不是就是几年前宣布五年内做出小型化核聚变装置的那个
|
S*******l
发帖数: 4637 | 38 上面那个加速器对撞的设计呢？
https://tae.com/fusion-power/
有希望么？
【在 f****i 的大作中提到】
: 托克马克对于美帝，就像加速器对于中帝一样
: 中帝有羊82，美帝也有羊92，美帝的羊92早在4个decade前就建议美帝退出毫无希望的
: 托克马克研究，
: 所以安了，这次美帝只是补课而已，所谓超强磁场，纯粹为了骗钱
|
f****i
发帖数: 1 | 39 你妈你如果读过nuclear fusion的课，第一课讨论的问题就是，为啥不能用加速器实现
聚变
【在 S*******l 的大作中提到】
: 上面那个加速器对撞的设计呢？
: https://tae.com/fusion-power/
: 有希望么？
|
n********g
发帖数: 6504 | 40 你在玉米地呆傻了不知道地球怎么转的情有可原
你说反了，应该是股市浮赢的有钱人太多，用这项目套现的
这些科研项目退税credit很厉害
我以前也开公司搞过，不过继承我前老板和前同事的观点，搞退税是骗钱没意思，（CS
）要搞创造交税的东西
看加州花不完的财政盈余怎么来的
【在 f****i 的大作中提到】
: 就像羊82建议包帝不搞加速器一样，
: 美帝理论界从80年代开始就认为托克马克没有希望，纯粹浪费时间，不建议搞
: 所以美帝退出托克马克整整4个decade了
: 这次mit只不过是补课而已，当然为了骗钱，为了吸引牛和娘这类有钱屁民的眼球，就
: 要放个火箭
: 这次美帝放的火箭是你们都他妈没有的超强磁场
|
S*******l
发帖数: 4637 | 41 那这公司是骗子公司了？
【在 f****i 的大作中提到】
: 你妈你如果读过nuclear fusion的课，第一课讨论的问题就是，为啥不能用加速器实现
: 聚变
|
z*****n
发帖数: 36 | 42 中子损伤，谁能解决谁就是燧人氏再世了。。。这个才是真正制约核聚变的要害
【在 f****i 的大作中提到】
: 搞笑，
: 周围都是真空，DT核聚变又不产生photon,主要是防止中子损伤而不是热损伤
|
S*******l
发帖数: 4637 | 43 这么一说就明白了，骗补贴掏国库的。
各国玩儿法都一样。
CS
【在 n********g 的大作中提到】
: 你在玉米地呆傻了不知道地球怎么转的情有可原
: 你说反了，应该是股市浮赢的有钱人太多，用这项目套现的
: 这些科研项目退税credit很厉害
: 我以前也开公司搞过，不过继承我前老板和前同事的观点，搞退税是骗钱没意思，（CS
: ）要搞创造交税的东西
: 看加州花不完的财政盈余怎么来的
|
n********g
发帖数: 6504 | 44 水
【在 z*****n 的大作中提到】
: 中子损伤，谁能解决谁就是燧人氏再世了。。。这个才是真正制约核聚变的要害
|
f***n
发帖数: 4682 | 45 留给他们的时间不多了
【在 S*******l 的大作中提到】
: 对
|
z*****n
发帖数: 36 | 46 你拿什么把水和超高温等离子体分隔开？
【在 n********g 的大作中提到】
: 水
|
f****i
发帖数: 1 | 47 属实，多大事啊，中子又不是photon，要是聚变产生的是14MeV的photon而不是中子，
估计到今天都没有人想搞这玩意
【在 n********g 的大作中提到】
: 水
|
n********g
发帖数: 6504 | 48 水在外围。磁铁和内壁是消耗品，1-2年一换。
另外，对撞机核聚变可能中子问题少一点。没研究。只是因为副产品是氦3。反应应该
部分吸收中子。
【在 z*****n 的大作中提到】
: 你拿什么把水和超高温等离子体分隔开？
|
y**h
发帖数: 3093 | 49 菌斑top1北航不是已经突破了吗
【在 S*******l 的大作中提到】
: commonwealth fusion system
: https://cfs.energy/
: 华尔街日报昨天报道刚融到18亿美刀，有啤酒瓶子什么的。
: https://eapsweb.mit.edu/news/2018/new-approach-fusion-energy
: 看了下是用高温超导磁体的托克马克装置，据说实现了能量正输出。
: 大牛们来批判一下，是不是核聚变发电实现在即。
: 这公司要上市那就是宇宙第一牛公司了。
|
z*****n
发帖数: 36 | 50 世界上不存在你说得这种内壁材料。天方夜谭看多了，对着画饼流哈喇子呢
【在 n********g 的大作中提到】
: 水在外围。磁铁和内壁是消耗品，1-2年一换。
: 另外，对撞机核聚变可能中子问题少一点。没研究。只是因为副产品是氦3。反应应该
: 部分吸收中子。
|
n********g
发帖数: 6504 | 51 先把聚变Q > 2做出来再说。如果不是很多千老说的Q > 10。
现在那规模放能放几个中子。等要取代切尔诺贝利级或者福岛级核反应堆时候再头疼内
壁能撑几天。
CS脑袋的优点就是实在，不为假设性问题费脑筋。
【在 z*****n 的大作中提到】
: 世界上不存在你说得这种内壁材料。天方夜谭看多了，对着画饼流哈喇子呢
|
z*****n
发帖数: 36 | 52 这尼玛就是骗钱的。。。。
【在 n********g 的大作中提到】
: 先把聚变Q > 2做出来再说。如果不是很多千老说的Q > 10。
: 现在那规模放能放几个中子。等要取代切尔诺贝利级或者福岛级核反应堆时候再头疼内
: 壁能撑几天。
: CS脑袋的优点就是实在，不为假设性问题费脑筋。
|
C*****l
发帖数: 1 | 53 这个就算磁场做出来，还要做大量的实验验证吧，这么早开公司是不是太猴急了 |
n********g
发帖数: 6504 | 54 钱不能等啊。再过几个月可能股市就膝盖斩了。现在投投资额算现在的市值。
【在 C*****l 的大作中提到】
: 这个就算磁场做出来，还要做大量的实验验证吧，这么早开公司是不是太猴急了
|
S*******l
发帖数: 4637 | 55 读一下吧，理论到应用对这个高温超导磁体托克马克装置的讨论
要点：
1.新的超导磁体制造方法，把稀土合金based 超导合金沉积在钢sheet上，可以克服超
导材料不易制造大磁体的困难，制造出实用大体积超导磁铁。
2.因为磁场强度强，等离子体束缚半径减小，装置体积可以大大减少。
3.超导磁体耗能小，有利实现正能量输出。
4.超导磁体可以装卸，有工程上的优势，可以把聚变反应器浸入熔盐，好像可以解决中
子轰击材料问题...
读完再议论一下。
https://www.sciencedirect.com/science/article/pii/S2542435119301254?via%
3Dihub
Fusion Energy: Research at the Crossroads
Author links open overlay panelMartinGreenwald1
https://doi.org/10.1016/j.joule.2019.03.013
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Martin Greenwald has worked in the field of magnetic fusion energy for more
than 40 years. He is the Deputy Director of MIT’s Plasma Science & Fusion
Center and a cofounder of Commonwealth Fusion Systems, a recent startup. Dr.
Greenwald’s research has focused on the turbulent transport of energy in
magnetically confined plasmas. He led a research team that was the first to
exceed the Lawson’s criteria for density-confinement product—a key fusion
goal. He is also the past chairman of the federal advisory committee for
fusion energy sciences.
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Keywords
fusion
tokamak
plasma
energy
high-field
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Main Text
Introduction
Fusion is the process by which light elements combine to form heavier
elements releasing enormous amounts of energy. It is the ultimate source of
energy in the universe, powering the sun and the stars and creating all the
elements of the periodic table. The fuels for fusion are deuterium, a
naturally occurring form of hydrogen, and lithium, each available abundantly
available on earth to meet humankind’s energy needs for millions of years.
The energy density contained in fusion fuels is so large that a mere 0.1 g
of deuterium, which is found in 3 gallons of ordinary water, would provide
the domestic and industrial electricity demands for a typical American for a
year. Fusion does not create greenhouse gases such as carbon dioxide,
pollutants such as sulfur dioxide or nitrogen dioxide, or particulates such
as soot. The fusion reaction would simply be a new source of heat used to
create steam to drive a turbine and generator—exactly the way that most
electricity is produced today. The need and the promise of fusion energy are
clear. The big question is whether it can be brought on line soon enough to
be part of the solution to global warming.
Fusion Basics
Practical fusion energy requires heating matter to extreme temperatures, on
the order of 200 million degrees. For two nuclei to fuse with useful
probability, they must approach each other to distances comparable to the
range of the strong nuclear force—about 10−15 m. Given their
electrostatic repulsion, this can only occur when they have kinetic energies
above 20 keV. Even at these energies, elastic scattering is about 100 times
more likely than a fusion reaction, so particles in a fusion device scatter
and thermalize. At such elevated temperatures, fuel atoms are fully ionized
, becoming an electrically conductive fluid called a plasma—the fourth
state of matter.
We can only reach such temperatures if the plasma is very well insulated
from ordinary matter. Ordinary insulation cannot be used because of the
temperatures involved; however, plasma is electrically conductive and can be
controlled and contained by strong magnetic fields. The basic principle is
simple—charged particles in a magnetic field revolve or “gyrate” in a
circular motion with a radius
(where m and E are the mass and energy of the particle, and B is the
magnetic field strength). This is only true for motion across a magnetic
field—along the direction of the field lines, the particles move freely and
would escape that way if allowed. So, to fully confine the plasma, the
field is arranged to eliminate the losses out of the ends by eliminating the
ends, leading to configurations with a characteristic toroidal or donut
shape. The quality of thermal insulation is measured as an energy
confinement time τE, which in most cases is dominated by turbulent
transport, driven by temperature and pressure gradients. A simplified,
single-parameter performance metric for fusion devices can be constructed as
the product of the fuel density (n), τE, and temperature (T), forming the
so-called triple product nτET.
The dynamics of a magnetized plasma is essentially a problem in classical
statistical physics, governed by Boltzmann’s equation, which describes the
plasma evolution in a six-dimensional phase space. The scientific challenge
is substantial; the systems have an enormous range of spatial and temporal
scales in complex geometry and are intrinsically nonlinear and strongly
coupled to atomic, nuclear, and materials processes.
The Situation Today
Fusion’s promise has spurred intense worldwide interest for decades. Years
of patient theoretical and experimental research has led to a vastly
increased understanding of how fusion systems work. In terms of performance,
there was a period of great progress from the late 1960s through to the
late 1990s. Over those 30 years, nτET increased by a factor of 10,000 (
Figure 1). This built confidence in the next step, i.e., construction of an
experiment that would produce a plasma that produced more fusion power than
what was required to sustain it and where self-heating from fusion would
dominate. One such device, named ITER, is now under construction in the
south of France by a consortium including China, the European Union, India,
Japan, Korea, Russia, and the United States.1
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Figure 1. The Fusion “Triple Product” nτET (1023 eV⋅s/m3) Is
Plotted versus Calendar Year
In the 30 years between 1968 and 1998, the rate of progress exceeded Moore’
s law. The dashed line shows the present time (as of this publication).
Projected schedule and performance are shown for two planned experiments.
At the same time, the fusion ecosystem is broadening. Privately funded
efforts are growing and seeking to accelerate the move out of the lab and
into the marketplace. These efforts validate the basic value proposition for
fusion and have provided new sources of ideas, expertise, and funding.
Given the scale of research funded by national governments, the private
programs have sought unique niches where their impact can be felt. An
industry association formed to promote fusion as a practical energy source
and to advocate policies that would speed up its realization.2 The
relationship between the private and public fusion sectors is evolving
rapidly with opportunities for private-public partnerships under discussion.
Challenge—How to Realize the Potential of the Technology Soon Enough to
Make A Difference
It is notable that the last point on the nτET curve in Figure 1 is 20 years
old. The apparent lack of recent progress is not due to fundamental
physical limits; rather, it is driven by the scale required. The cost for
possible next-step devices was very high, and they were difficult to fund
and hard to organize. Costing the equivalent of several tens of billion US
dollars, ITER is the largest research device ever built. Technical issues
that will remain after ITER’s successful completion have been recognized
and extensively documented by the community,3 but there is no programmatic
sense of urgency to address them. As a result, most national roadmaps do not
see fusion power making much of an impact before the end of this century.
The disconnect between the pace of the national programs versus the needs
and expectations of stakeholders outside the program is profound and gives
rise to existential concerns. At some point, delay may be the equivalent to
failure if policy makers and industry conclude that no solution will be
forthcoming.3
The Technical Basis for a Fusion Energy Breakthrough Is Here
While fusion research can be carried out on machines with conventional
copper electromagnets, a fusion power plant must employ superconductors or
their enormous power consumption would prevent the system from ever
producing net energy. Until very recently, the best-performing
superconductors were made from niobium-tin (Nb3Sn) cooled to liquid helium
temperatures. The breakthrough has come in a new class of superconductors,
compounded from rare-earth barium copper oxide (REBCO). These were first
discovered in 1986 and were notable for their ability to retain
superconducting properties at much higher temperatures.4 More importantly
for this story, the new materials labeled high-temperature superconductors (
HTSs) retain their superconducting properties even when embedded in very
strong magnetic fields. Their potential for fusion was recognized
immediately,5 but the new superconductors were in the form of fragile
crystals and not useful for building magnets. Since then, researchers have
found ways to deposit the superconducting compound as thin films on a strong
steel substrate. The resulting conductors—in the form of “tapes” or “
ribbons”—have been used to build magnets with unprecedented performance.6
For fusion, this changes everything. To understand why ITER had to be so big
, we go back to the basic ideas for magnetic fusion. The main energy-loss
mechanism for confined plasmas is through turbulent convection. The
turbulent fluctuations tend to be concentrated at scales that are a few
times the ion gyro-radius. At higher magnetic fields, the gyro-radii are
smaller, so the turbulent scales and transport are reduced. The figure of
merit for the quality of thermal insulation is the number of gyro-radii
across the plasma, R/ρ, which is proportional to BR, the product of the
magnetic field strength B and the device size R. Figure 2 shows this result
graphically, plotting fusion gain versus B and R (a fusion power plant would
need a gain greater than 20). The general shape of the curves is given by
the simple arguments above, but the precise values of each curve required a
significant body of research. With conventional superconductors, the region
of the figure above 6T was inaccessible; thus, ITER, with its older magnet
technology, is as small as it could be. HTS more than doubles the range of
magnetic fields achievable, opening up the possibility of smaller, higher-
field devices. Since their weight and volume scale with the size cubed, this
greatly reduces the costs. That is, we can trade off B for R in a fusion
design, and B is much cheaper than R. This was demonstrated by a series of
compact high-field tokamaks built and operated at MIT in the last several
decades, which set a number of significant fusion plasma performance records
in their time.7, 8 The basic argument has been endorsed in a finding of a
recent National Academy Study9: “The rapid progress in HTS magnets may
enable significant reductions in the size of magnetic fusion devices and
support the compact lower-cost pathway to fusion development.”
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Figure 2. Contours of Constant Fusion Gain (PFUSION/PINPUT) Are Plotted
versus Magnetic Field and Device Size
The shape of the curves arises from very general arguments about magnetic
confinement of plasmas. High-temperature superconductors allow operation
above 6T, allowing compact, high-field devices to produce as much fusion
power as the larger ones. Two possible burning plasma devices, ITER and ARC,
are shown to scale.
The High-Field Path for Fusion Energy
Producing the class of large-volume, high-field superconducting magnets
needed for fusion will require overcoming significant challenges in
structural and cryogenic engineering and quench dynamics. MIT and
Commonwealth Fusion Systems (CFS) have partnered to carry out the necessary
research and development. Strategies must also be developed for managing the
heat flux and the interface between the hot plasma and ordinary matter.
Work thus far suggests that there are no fundamental obstacles in pursuit of
this goal. The collaboration is structured to help bridge the “valley of
death”—the gap that can open up between the level of technical readiness
typically established by academic or government research and the level
required to attract private investment.
Once the magnet development is successful, the next step will be to build
and operate SPARC, a type of magnetic confinement device called a tokamak.10
SPARC could be the first fusion experiment with a plasma that produces more
fusion power than what is input to keep it hot, a goal of the fusion
program for more than 60 years. A rendering of the SPARC device can be seen
in Figure 3. With a plasma volume of 15 m3, SPARC would be a mid-sized
fusion experiment of a size and configuration similar to many machines
already in operation. With the new HTS magnet technology, it will have an
average field in the plasma of 12 Tesla. Based on data from decades of
research on dozens of experiments around the world, we can be reasonably
confident that a machine with these specifications would reach the net power
milestone while producing more than 50 MW of fusion power.
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image
Figure 3. A Rendering of SPARC, a Compact, High-Field Tokamak
With performance enabled by high-temperature superconducting magnets, the
SPARC plasma should produce more power than the external heating required to
sustain it.
The next step in this roadmap would be to build and operate a pilot plant,
aimed at putting electricity from fusion power onto the grid. Its goal would
be to demonstrate the science and technology required for economically
competitive mass production of fusion energy. We can get some idea about
what this might look like from the high-field ARC concept.11 Running at 9.2
Tesla, ARC is about half the linear dimension of ITER but could produce the
same fusion power. Power plants of this size are a good match to the needs
of the existing electrical grid. Smaller unit sizes may also allow a
deployment strategy where all components are built in factories and shipped
to sites for assembly, obviating the need for expensive and inefficient on-
site fabrication.
Consideration of the ARC pilot plant highlighted the opportunities for
further innovations. For example, the higher specific heat of materials at
higher temperatures, combined with additional operational margin afforded by
HTS, should allow construction of superconducting coils with demountable
joints. This concept could revolutionize the construction and maintenance of
fusion devices, which otherwise have components trapped by their toroidal
field coils. Since fusion power plants need a “blanket” to breed tritium,
shield the magnets, and extract thermal energy, demountable magnets are
synergistic with an additional innovation: the provision of all blanket
functions through immersion of the fusion core in a bath of molten salt.
This blanket concept dramatically reduces the volume of solid material
exposed to high neutron flux, further simplifies maintenance, and enables a
development path for fusion materials in which replaceable cores are
installed successively as part of the research and development program.
Prospects
A new technology, high-temperature superconductors, provides the technical
basis for acceleration of fusion energy development, by increasing the
magnetic field and decreasing the size of fusion systems. The faster
timescales thus enabled drive the need for rapid innovation in other
technical areas. The synergy between government-funded basic research and
privately funded efforts focused on commercialization is growing within the
fusion ecosystem, following highly successful examples from other fields.
While a great deal of work will be required, and significant hurdles must be
overcome to take advantage of the confluence of needs and opportunities,
there is good reason to be optimistic that the promise of fusion energy will
finally be realized.
Acknowledgments
This work is a summary of ideas developed by the SPARC team in recent years.
Ongoing funding is provided by Commonwealth Fusion Systems. |
f****i
发帖数: 1 | 56 这都是基于托克马克理论上能够实现这个大前提上面的
我早说了，祖国有反对加速器的羊82，美帝有反对托克马克的羊92，
早在80年代里根政府在美国羊92的劝说下全面放弃了托克马克
到今天已经放弃整整40年了，你说还能再捡起来么？
【在 S*******l 的大作中提到】
: 读一下吧，理论到应用对这个高温超导磁体托克马克装置的讨论
: 要点：
: 1.新的超导磁体制造方法，把稀土合金based 超导合金沉积在钢sheet上，可以克服超
: 导材料不易制造大磁体的困难，制造出实用大体积超导磁铁。
: 2.因为磁场强度强，等离子体束缚半径减小，装置体积可以大大减少。
: 3.超导磁体耗能小，有利实现正能量输出。
: 4.超导磁体可以装卸，有工程上的优势，可以把聚变反应器浸入熔盐，好像可以解决中
: 子轰击材料问题...
: 读完再议论一下。
: https://www.sciencedirect.com/science/article/pii/S2542435119301254?via%
|
n********g
发帖数: 6504 | 57 1、都说了。就是造磁铁的。MIT搞核的哪里露脸出来丢人了。
2、现在的问题不是小型化，而是Q < 1
3、Q> 1以后的确低耗能磁铁会有帮助，也许不需要Q > 10，也许Q > 2就够了。
但是无论如何，Q还是越大越好。否则投资回报比太低。
人类种地Q可以达到50以上。这才是革命。
【在 S*******l 的大作中提到】
: 读一下吧，理论到应用对这个高温超导磁体托克马克装置的讨论
: 要点：
: 1.新的超导磁体制造方法，把稀土合金based 超导合金沉积在钢sheet上，可以克服超
: 导材料不易制造大磁体的困难，制造出实用大体积超导磁铁。
: 2.因为磁场强度强，等离子体束缚半径减小，装置体积可以大大减少。
: 3.超导磁体耗能小，有利实现正能量输出。
: 4.超导磁体可以装卸，有工程上的优势，可以把聚变反应器浸入熔盐，好像可以解决中
: 子轰击材料问题...
: 读完再议论一下。
: https://www.sciencedirect.com/science/article/pii/S2542435119301254?via%
|
C*****l
发帖数: 1 | 58 只是磁场就比Iter高了一倍，其实后面的物理问题，plasma控制问题，还有的研究。这
玩意看上去就是还要再研究20年的样子。
【在 f****i 的大作中提到】
: 这都是基于托克马克理论上能够实现这个大前提上面的
: 我早说了，祖国有反对加速器的羊82，美帝有反对托克马克的羊92，
: 早在80年代里根政府在美国羊92的劝说下全面放弃了托克马克
: 到今天已经放弃整整40年了，你说还能再捡起来么？
|
n********g
发帖数: 6504 | 59 我不觉得MIT会去研究。我猜这公司的商业计划是卖磁铁给ITER。
【在 C*****l 的大作中提到】
: 只是磁场就比Iter高了一倍，其实后面的物理问题，plasma控制问题，还有的研究。这
: 玩意看上去就是还要再研究20年的样子。
|
C*****l
发帖数: 1 | 60 ITER的设计完全不一样，早就找好分包商了
【在 n********g 的大作中提到】
: 我不觉得MIT会去研究。我猜这公司的商业计划是卖磁铁给ITER。
|
