Space, time & Cosmos
Lecture 8:
Fusion energy and the Moon
Dr. Ken Tsang
Peak Oil
Peak oil is the point in time when the maximum rate of
global petroleum extraction is reached, after which
the rate of production enters terminal decline.
The aggregate production rate from an oil field over
time usually grows exponentially until the rate peaks
and then declines—sometimes rapidly—until the
field is depleted. This concept is derived from the
Hubbert curve, and has been shown to be applicable
to the sum of a nation’s domestic production rate,
and is similarly applied to the global rate of
petroleum production.
A bell-shaped production curve, as originally
suggested by M. King Hubbert in 1956.
U.S. Oil Production
and Imports 1920
to 2005
Norway's oil production and a Hubbert curve approximation
2004 U.S. government predictions for oil production other
than in OPEC and the former Soviet Union
Peak coal
• Peak coal is the point in time at which the maximum global coal
production rate is reached, after which, according to the theory,
the rate of production will enter irreversible decline. Coal is a
fossil fuel formed from plant matter over the course of millions
of years.
• Hubbert noted that United States coal production grew
logarithmically at a steady 6.6% per year from 1850 to 1910.
Then the growth leveled off. He concluded that no finite
resource could sustain exponential growth. At some point, the
rate of production will have to peak and then decline until the
resource is exhausted. He theorized that production rate plotted
versus time would show a bell-shaped curve, declining as rapidly
as it had risen.[2] Hubbert used his observation of the US coal
production to predict the behavior of peak oil.
Peak coal in China & USA
• China is the world’s largest coal producer and has the
second largest reserves after the United States. The
Energy Watch Group predicts that the Chinese
reserves will peak around 2015.
• Coal production in the United States, currently the
world's second largest producer, has undergone
multiple peaks and declines. In 1956, Hubbert
estimated that US coal production would peak in
about the year 2150. In 2004, Gregson Vaux used the
Hubbert model to predict peak US coal production in
2032
Our options in energy
• Fossil fuels – greenhouse effect, not enough supply.
• Wind, solar, bio-fuel – expensive, not enough, can
only play a supplementary role.
• Nuclear Fission – safety & proliferation concern,
radioactive waste & supply problem.
• Nuclear Fusion – scientific breakeven & engineering
feasibility needed to be demonstrated, active & huge
international research effort going on, looks
promising. Potentially unlimited supply for future
energy.
You don’t need heavy math &
physics to understand Nuclear
Energy
• All you need are very simple and basic
concepts…
#1: equivalence of energy and mass
• Einstein’s famous formula
•E =
2
mc
#2: nuclear binding energy
• Inside a nucleus, there are particles called neutrons and protons
(nucleons).
• Nuclear binding energy is the energy required to disassemble a
nucleus into free unbound nucleons, or
• binding energy = mass deficit
= sum(masses of all nucleons) – mass of nucleus
• For example, the binding energy for C12 is
= 6*(proton mass) + 6*(neutron mass) – mass of nucleus of C12
• In the process of forming the nucleus some mass is transformed
into energy and released.
• Nucleus of different chemical element has different binding
energy.
Nuclear Binding energy for
common elements (isotopes)
Nucleus with low binding energy is more
unstable like sitting on top of a hill
-Binding energy
Low binding energy
Hi binding energy
Tapping the Nuclear Binding energy
Total number of nucleons in nucleus
Nuclear energies
• Nuclear fission – heavy nucleus disintegrate to
lighter ones and release energy in the process
• Nuclear fusion – light nucleus joint together to
form heavier one, releasing energy in the
process
Comparing nuclear & chemical energies
The enormity of the nuclear binding energy can perhaps be better
appreciated by comparing it to the binding energy of an electron in an
atom. The comparison of the alpha particle binding energy with the
binding energy of the electron in a hydrogen atom is shown below. The
nuclear binding energies are on the order of a million times greater than
the electron binding energies of atoms.
Nuclear fission reactions are produced
by human in laboratories, fission
reactor, and A-bombs.
The mushroom cloud of the atom
bomb dropped on Nagasaki, Japan
in 1945 rose some 18 kilometers (11
miles) above the bomb's hypocenter.
Furthermore…
• Protons are positively charged.
• The number of protons in a nucleus is called
the atomic number, it determines the
chemical properties.
• When you have more than one proton in a
nucleus, neutrons are needed to hold the
mutually repulsive protons together.
• The more protons are present in the nucleus,
the more neutrons are needed.
Isotopes – same atomic number but different mass
number
Isotopes of elements
Heavy nucleus need more neutrons to maintain stability.
However, there is no stable nucleus beyond Z>83, no
matter how many neutrons are inside the nucleus.
Graph of the number of
neutrons versus the number of
protons for all stable naturally
occurring nuclei. Nuclei that lie
to the right of this band of
stability are neutron poor;
nuclei to the left of the band
are neutron-rich. The solid line
represents a neutron to proton
ratio of 1:1.
Chain reaction
• When a nucleus undergoes fission, a few
neutrons (the exact number depends on the final products)
are ejected from the reaction, because lower Z
nuclei do not need as many neutrons to
maintain stability.
• If more fissile fuel is around, these free
neutrons may be absorbed and cause more
fissions. Thus, the cycle repeats to give a
reaction that is self-sustaining.
In fission weapons, a mass of fissile material
(enriched uranium or plutonium) is
assembled into a supercritical mass—the
amount of material needed to start an
exponentially growing nuclear chain
reaction—either by shooting one piece of
sub-critical material into another (the
"gun" method), or by compressing a subcritical sphere of material using chemical
explosives to many times its original
density (the "implosion" method).
It is easier to achieve self-sustaining
Nuclear fission than…
The Manhattan Project, conducted during World
War II primarily by the United States, officially
took only 4 years (1942–1946) to produce the
first atomic bomb.
It is more difficult to achieve fusion
because…
Diagram here illustrates the technical difficulties of nuclear fusion, which must
bring positively charged nuclei close enough so that the nuclear force will kick in.
This can only occur in an extremely hot environment, such as the core of the Sun.
An example of nuclear fusion:
D + T  He + n + 14.1Mev
The only fusion reactions thus far produced
on Earth to achieve ignition are those
created in hydrogen bombs, the first of
which, Ivy Mike, is shown here. The
ignition is achieved by using an atomic
bomb as trigger.
Fission energy is not environmental
friendly because…
• Fission produces many neutrons, and
• Neutrons are evil because
– Thick blanket for shielding… not economical
– Produce many secondary radiative wastes with long life… not green
– Energy recoverable only from heat… not efficient
• Handling radiative waste is a big problem for fission reactor –
expensive
• The chain reaction has to be controlled carefully so that it will
not run-away as in a bomb – safety problems (Three Mile Island
1979, Chernobyl 1986)
The reactor is a way of getting energy from the uranium fission in a controlled way.
The first nuclear fission reactor was made by Enrico Fermi in a squash court in
Chicago in 1942, as shown in the diagram.
Three Mile Island Nuclear Generating Station
The CANDU Qinshan Nuclear Power Plant (Zhejiang)
Issues of nuclear fission power
• Economy
• Safety – stability in operation, radiation protection,
redundant backups
• Security – terrorist, proliferation concern
• Waste disposal – spent nuclear fuel, contaminated
soil, water, clothing and sheilding materials
• Supply of fuels - Uranium
Fusion energy is inherently
• Safer – the problem is to maintain the
thermonuclear condition, no worry on runaway
• Cleaner – no neutron produced (except DD or
DT reactions), sheilding is not a big problem
• More efficient – most energy carried by charged
particles, easier to convert to electricity
Neutron shielding in a fusion reactor
• D-T is the most easy reaction to achieve
breakeven, but most of the energy embedded
in the 13-Mev neutron, which requires a thick
(i.e. expensive) reactor first-wall to absorb its
energy.
• DHe3 & He3He3 reactions do not generate
neutron at all, so their energy can be directly
converted to electricity at high efficiency.
International Thermonuclear
Experimental Reactor (ITER)
• An international tokamak (magnetic confinement fusion)
research/engineering project that will help to make the
transition from today's studies of plasma physics to future
electricity-producing fusion power plants.
• The program is anticipated to last for 30 years — 10 for
construction, and 20 of operation — and cost
approximately €5 billion (US$7.6 billion).
• It will be based in Cadarache, France. It is technically ready
to start construction and the first plasma operation is
expected in 2016.
• On September 24, 2007, the People's Republic of China
became the seventh party who had deposited the ITER
Agreement to the IAEA.
Solar wind - product of fusion reactions in the Sun
Origin of Lunar He-3
Why does helium-3 exist only on
the Moon and not on Earth?
• The Moon has no atmosphere, and
• No magnetosphere.
Solar wind and the Earth’s magnetosphere
Distribution of Helium-3 on the lunar
surface depends on
• Solar wind fluence
• Soil chemistry, in particular the titanium
content, because ilmenite (FeTiO3) retain
helium-3 much better than other major lunar
minerals
• Lunar surface optical maturity
Most recent model calculation
combining
• the model of relative solar wind flux over
lunar surface
• global distribution of TiO2 content, and
• surface optical maturity derived from
Clementine UV/VIS multispectral data
Quantitative estimation of helium-3 spatial distribution
in the lunar regolith layer
Wenzhe Fa, Ya-Qiu Jin
Fudan University, Shanghai 200433, China
Available online 11 April 2007
Distribution of normalized solar wind flux over
lunar surface
(a) nearside, (b) farside. It is assumed that the Moon is fully exposed to the solar wind
75% of the time and fully shielded for the remaining 25% of the time in each lunation
Most recent theoretical estimate of
lunar He-3 reserve
• Using the Apollo lunar samples and Clementine
UV/VIS multispectral data, three factors: solar wind
flux, regolith maturity, and TiO2 content, are
combined for estimation of global 3He surface
distribution.
• The lunar inventory of He-3 is estimated as about
6.50 × 108 kg, with 3.72 × 108 kg on the lunar
nearside and 2.78×108 kg on the lunar farside.
Chang’e Project 嫦娥工程 & He3
• Cosmochemist and geochemist Ouyang Ziyuan from
the Chinese Academy of Sciences who is now in
charge of the Chinese Lunar Exploration Program has
already stated on many occasions that one of the
main goals of the program would be the mining of
helium-3
• "Each year three space shuttle missions could bring
enough fuel for all human beings across the world,"
said Ouyang - China Daily: 2006-07-26
我国绕月探测工程首席科学家
欧阳自远 Ouyang Ziyuan
欧阳自远先生与佘山天文台副台长叶叔华女士做的一次关
于“欧洲智能一号与中国嫦娥一号”比较的演讲
• 探测土壤厚 度，估测He-3资源。He-3作为月
球最重要的矿产之一，对于未来的能源走向
有很明显的指向作用，哪个国家能够先挖掘
出He-3的利用方式就能在未来的能源战中取
得优势。He-3的优点在于无辐射，可靠，廉
价，安全，有效。它的核聚变产生的能量约
为一般的核电厂产生能量的93倍，估计月球
上He-3的储 量大约在180万上下，足够地球
未来上万年之用。
• http://www.astron.sh.cn/cgibin/topic.cgi?forum=20&topic=31&show=0
Chang'e 1 spacecraft, China's first lunar probe
satellite
Launch date
2007-10-24 18:05:04.602 CST
at Xichang Satellite Launch Center
Chang'e 1 - Objectives
• Complete coverage of the Moon and obtaining threedimensional images of the lunar surface, including areas
near the north and south poles not covered by previous
missions.
• Probing useful elements on the Moon surface and
analyzing the elements and materials, including Ti.
• Probing the features of lunar soil and evaluating its
depth, as well as the amount of helium-3 (³He) resources.
• Recording data on the primitive solar wind and studying
the impact of solar activity on the Earth and the Moon.
Instruments on Chang’E-1:
All aims at 3He
• Stereo camera with an optical resolution of 120 m and
spectrometer imager from 0.48 μm to 0.96 μm wavelength.
• Laser altimeter with 1064 nm, 150 μJ laser and a resolution of
1 m.
• Gamma and X-ray spectrometers for an energy range from
0.5 to 50 keV for x-rays and 300 keV to 9 MeV for gamma rays.
• Microwave radiometer detecting 3, 7.8, 19.35 and 37 GHz
with a maximal penetration depth of 30, 20, 10, 1 m and a
thermal resolution of 0.5 K.
• High energy particle detector and two solar wind detectors
capable of the detection of electrons and heavy ions up to
730 MeV.
Chinese Lunar Exploration Program structure
• Orbital mission (Chang'e 1 & 2)
– Chang'e 1: successfully launched as scheduled on October 24, 2007,
controlled impact onto the surface of the Moon on March, 1st, 2009.
– Chang'e 2 is scheduled to be launched in 2009-10.
• Soft lander (Chang'e 3 & beyond)
– two lunar landers will be launched to deploy moon rovers
for surface exploration in a limited area. These missions
were originally planned for 2012.
探月載人飛船
Apollo 系列 15次， 14次成功 (1967年11月9日– 1972年12月7日)
Apollo 4
67年11月9日發射
首次 Saturn V 試飛 (無人)
Apollo 8
68年12月21日發射
Apollo 11
Saturn V
首次載人繞月
Apollo 11
69年7月16日發射
首次載人登月 (7月20日)
Apollo 17
72年12月7日發射
系列最後一次登月(12月11日)
載人太空船包括兩部份：
操控囊+登月囊
帶回月球樣本共382公斤。
Apollo 17 Mare basalt
休整期 (1973 – 1994)
90年1月24日
日本發射Muses-A探測器，有兩部份:
Hiten 與 Hagoromo。
Hagamoro 在3月放出繞月，但失去聯絡。
Hiten為第一部利用低能量軌道的探測器 (缺燃料)。
新一輪的熱潮 (1994開始)
可能有水
美國
Clementine
94年1月25日發射
在繞月三個月間發回一百八十萬張數碼圖片。
重大科學發現:某些月球的撞擊坑內可能有水。
Lunar Prospector
Lunar Prospector
1998年1月7日發射
中子譜儀探測水的氫原子。
都卜勒引力實驗探測月球重力塲，証明
月核很細小，支持撞擊分離假設。
Hall thruster
歐盟
SMART-1
2003年9月27日發射
solar-powered Hall effect thruster
利用低能量軌道
2005年3月15日開始繞月(400-3000公里)
2006年9月3日撞月
日本
月亮女神
2007年9月14日發射
帶兩顆小衛星作定位通訊用
中國
嫦娥1號
2007年10 月24日發射
科學儀器已全部啟動
Impacted Moon on March 1, 2009
SMART-1 orbit
印度
2008年10月22日發射 Chandrayaan 1
11月8日開始繞月
美國
將於2009年6月發射 Lunar Reconnaissance Orbiter
俄羅斯
將於2012年發射 Luna-Glob
德國
將於2012年發射 Lunar Exploration Orbiter
“India has joined the race for Helium-3, a replacement
for fossil fuels, with the USA, Russia, Japan, Europe,
and China with Chandrayaan's launch…”
http://www.khabrein.info/index.php?option
=com_content&task=view&id=21375&Ite
mid=62
Chandrayaan-1 now in lunar orbit
It has been estimated that helium 3 would have a cash
value of $5.7 Million per kilogram in terms of its
current energy equivalent to oil at <$40 per barrel oil.
At $40,000 to $60,000 per kilo for transporting
materials from Earth to the Moon, it is not cost
effective to go to the Moon for pure gold. But
He3’s equivalent energy value in today’s dollar
makes this venture for the He3 fusion reactant
worth the effort and cost.
A space vehicle with a payload bay the size of a
space shuttle could bring back enough
helium-3 to generate the electricity to satisfy
the United States’ needs for a full year.
“There is more than 100 times more energy in
the helium-3 on the moon than in all the
economically recoverable coal, oil, and natural
gas on earth.”
Dr. Larry Taylor, director of UT’s Planetary Geosciences Institute
The Moon may be “the Persian
Gulf of energy in the 21st
century.”
Helium 3 Fusion Fuel Mineral Rights on the Moon! January 19, 2007
Trio of North American Scientists Claim 'Mineral Rights' to 75% of Moon. Dr.
Joseph Resnick, Dr. Timothy R. O'Neill and Guy Cramer (ROC team) are
attempting to secure the 'mineral rights' to areas of the Moon of particular
scientific, commercial and historic interest in order to preserve the areas
from potential future commercial mining and development. According to
Resnick, "Space law does not allow countries to have land ownership on
planets and moons in the solar system, but it does allow for the 'mineral
rights' to be obtained by individuals and companies." The main mineral in
question is helium-3 (He-3). Scientists estimate there is about 1 million tons
of He-3 on the Moon, enough to power the entire world for over a
thousand years. Dr. Larry Taylor, director of UT's Planetary Geosciences
Institute in Knoxville TN says, "You can find ways to process or mine the
Moon and its soil, but there's a lot of stuff up there that we could use down
here too. The abundance of helium on the Moon represents 'the Persian
Gulf of energy in the 21st century.'" Once the ROC team established the
Universal Mineral Leases Registry to register their claims of the specific
areas (including the Apollo 11 landing site as a 'World Heritage Site'), the
Registry was made available to the public online.