Frequently Asked Questions

Questions / Answers

  • What is HiPER?

HiPER stands for High Power laser Energy Research facility

HiPER is a proposed international laser facility which is being designed to demonstrate the feasibility of laser driven fusion as a future energy source, and to enable the study of a wealth of fundamental scientific topics in the “physics of truly extreme conditions”.

It will build from the upcoming “proof of principle” demonstration of laser fusion, anticipated on the National Ignition Facility (USA) at the turn of the decade.

It will open up entirely new areas of scientific research, providing access to physics regimes which cannot be explored on any other facility. This will cover areas as diverse as laboratory astrophysics, extreme material science, turbulence, and fundamental atomic, nuclear and plasma physics.

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  • Who is involved and what stage are they at?

HiPER has completed a 2-year design study involving senior scientists from 12 nations. The conclusions of this study allowed HiPER to be selected onto the European roadmap for future large-scale science facilities. See:

HiPER has now entered a 3-year project to address the financial, legal, strategic and technical issues required to inform a decision on construction. This phase is funded by the European Commission and a number of national funding agencies. 

In addition, there are very significant “in kind” contributions from many partners. Most significantly, the PETAL laser in the Aquitaine region of France has been strategically aligned to the HiPER project to address many important issues related to the successful achievement of the HiPER facility. See

The current phase has partners from 26 institutions in 10 countries, including representation of 6 European nations at the governmental or national funding agency level, 2 regional governments and has direct involvement from industry.

The nations involved at “partner” level are: Czech Republic, France, Greece, Italy, Spain, and the UK. In addition, the Conseil Régional d’Aquitaine (France) and the Comunidad Autonoma de Madrid (Spain) are involved at the regional government level.  Institutions and scientists from Russia, Germany, Poland and Portugal are also directly involved in the project. 

Scientists from the USA, Japan, China, Republic of Korea and Canada are involved via international collaborations, making a total of 15 nations now associated with HiPER.

The objective of this “preparatory phase” is to establish a clear path for the construction of HiPER. This will involve an assessment of the options in terms of the technology choices and the associated impact, feasibility and cost.

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  • What is fusion?

Fusion has been called the “holy grail” of energy sources – combining abundant fuel with no greenhouse gas emissions, minimal waste products, and a scale that can meet mankind’s long-term energy demands

Fusion is the combination of small atomic nuclei into a larger nucleus.  As predicted by Einstein (E=mc2), this process can release a large amount of energy

Fusion is the process that powers the Sun and all the stars.

Earth-based fusion reactors use Deuterium and Tritium (isotopes of Hydrogen) to create Helium gas and a neutron. The helium is used to drive subsequent fusion reactions (creating a self-sustaining process).  The neutron is captured in a “blanket” surrounding the fusion chamber – it deposits its energy such that the blanket heats up. This heat is used to drive a conventional steam turbine power plant.

Fusion power plant designs are typically at the multi-Gigawatt scale.

Sea water and the Earth’s crust contain the main fuel source (Deuterium, and Lithium to create Tritium). There is sufficient fuel on Earth to last into the far future.

Energy security is a natural feature of fusion, because the fuel is found across the globe.

Fusion has been pursued for many years. In the early days of fusion (in the 1950s and 60s), it was thought that the process could be harnessed easily. This was proven not to be the case, but after many years of investment, scientists now believe there are two attractive routes to fusion power. One uses large scale magnetic fields (the approach adopted by the international ITER reactor). The other uses very high power lasers (the approach adopted by HiPER).

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  • What is INERTIAL fusion?

Two different schemes have emerged that have led to the construction of huge infrastructures.

In the “magnetic confinement” scheme, a low density hot plasma is confined by magnetic fields in toroidal (doughnut-shaped) geometry. The international “ITER” facility is being constructed to lead to the demonstration of net fusion energy production at an industrial scale (~0.5 GW) for the first time.

“Inertial confinement” fusion (also called laser fusion) is based on creating much higher densities for much shorter timescales, using tiny (mm-size) pellets containing the fuel. These pellets are imploded using high power laser beams. This leads to fusion reactions taking place inside the compressed fuel at more than a thousand times solid density for a few tens of picoseconds (1 picosecond = 1 millionth of a millionth of 1 second).   For a power plant this process is then repeated 5 or 10 times a second to create a continuous flow of electricity at the Gigawatt scale. This is conceptually similar to a car engine, in which fuel is injected, compressed and ignited many times a second. But for fusion, the energy release is far, far greater.

Present estimations predict the achievement of net fusion energy production for a laser energy of 1 million Joules (a megajoule). Two large laser facilities at this scale are presently under construction: one in France (LMJ: Laser Mégajoule) and one in the USA (NIF: National Ignition Facility). NIF will be operational in 2009.  These facilities are anticipated to generate over 10 times more energy than delivered by the laser. They will adopt a “conventional” approach to inertial fusion using laser generated x-rays to drive an implosion which compresses the fuel. That is, the laser is used to create x-rays to force the fuel together until it ignites.

Whilst conceptually simple, this “conventional” approach requires a very high quality laser and very high quality targets. This translates into very expensive components, which are perhaps difficult to translate into a commercial power plant.   HiPER plans to use an advanced, more efficient approach called “fast ignition”. This is still in the developmental phase, but would allow smaller laser infrastructure and higher energy gain.

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  • Will inertial fusion work?

Net energy production from inertial fusion has already been demonstrated on Earth in an offshoot of the US defence mission in the 1980s. What now remains is to demonstrate energy production in the laboratory using a laser. This is anticipated on NIF in the period 2010 to 2012 marking the culmination of many decades of research.

This will be a highly significant event. Termed “ignition” it will show that more energy can be produced by laser fusion than is required to drive the process – i.e. a scalable source of energy production. It is essential that we clearly understand the future path to an energy programme following this scientific “proof of principle”. This will require international cooperation over the next decade to produce the leap in technology to allow this scientific demonstration to be converted into an exploitable solution.   The HiPER project has been designed to drive this technology development by building a next generation laser facility operating at a high repetition rate. Europe is ideally placed to lead the world in this journey, but requires a focused programme to ensure timely progress.

The HiPER project has been developed to provide a clear path forwards from the demonstration of laser fusion “ignition”. Its approach is based on a strong science mission that will deliver leading-edge results throughout the life of the facility.

This approach will allow us to answer the political and public questions of what to do after NIF achieves energy production.

The process of inertial fusion is shown schematically on this website.

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  • Why is fusion attractive?

Fusion does not release carbon dioxide into the atmosphere, which is believed to be a factor in global warming

Fusion fuel is found in seawater and the earth’s crust, so energy security is assured.

The amount of fusion fuel on Earth is sufficient to last for thousands of years.

Only short lived radioactive waste will be produced, such that the decommissioning of a fusion power plant is readily achievable.

Fusion does not rely on a large fuel mass, and so ‘melt down’ is not possible.

The high temperatures created by fusion can be used to drive a Hydrogen production cycle.  Hydrogen is needed as the fuel for a new, carbon-free solution to mobile energy (e.g. to power vehicles).  So fusion can provide energy both for the national grid and to supply local, mobile power sources.

As such, the benefits of fusion energy cannot be overstated in the current global setting where climate change, pollution, energy security and the ever increasing demand for consumption represent a principal challenge facing mankind. It is a long-term, sustainable solution that will take a concentrated research and development effort across a range of options to realise its potential.

Fusion is a long-term solution to the problem of finding a source of abundant clean energy. It is not a solution to the immediate term problem of climate change, which will require a combination of techniques (probably including a suite of renewable sources, fission, energy efficiency and reduction in demand where possible).


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  • Who discovered fusion and when?

The discovery of fusion cannot be attributed to a single person but a collection of discoveries by many different scientists.

In 1905 Einstein published the famous equation E=mc2 , which equated energy and mass. In 1920, Francis William Aston first discovered four separate hydrogen nuclei were heavier than a single helium nucleus. On the basis of this work, Arthur Eddington proposed in 1920 that the Sun could get energy from converting hydrogen nuclei into helium nuclei (via E=mc2). In 1939 Hans Bethe then distilled these facts into a quantitative theory of energy production in stars, which eventually led to him winning the Nobel prize in 1968.

The first tentative fusion experiments were carried out in the Cavendish laboratory in Cambridge (UK) during the 1930’s, but serious effort was not applied until the 1950’s when the ZETA device was built at the Harwell site in the UK.

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  • Why invest in fusion when we have mature renewable technologies like wind and solar power?

Renewable technologies like wind and solar power are already being exploited. However they are only expected to account for a target value of 10% of energy generation by 2010, and perhaps 30% in the long term.

For a reliable national grid there needs to be a relatively constant method for generating the base load requirements. This is currently fulfilled by fossil fuel burning power stations and nuclear fission reactors.

A fusion power station would be a direct, non carbon producing alternative.

The basic fuel is found in seawater and so energy security is greatly enhanced, removing the reliance on regionally based fuel sources.

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  • There is already a major fusion project underway called ITER. Why build HiPER if ITER is already being built?

Fusion represents a very attractive energy source for the future in that the fuel supply is almost inexhaustible, there are no carbon emissions and only short lived radioactive isotopes are produced. Fusion is a ‘grand challenge’, tackling one of the most compelling problems facing mankind.  As such, it is highly desirable to pursue a number of complementary solutions. 

ITER represents one route for producing fusion but it is sensible to investigate other options to ensure fusion technology can be fully developed to meet our long-term needs.

Multiple routes exist for fossil fuel sources (oil, gas, coal, etc) and renewable sources (wind, wave, solar, etc). Similarly, we must plan for multiple routes for our long-term energy requirements.

Inertial fusion offers some unique benefits – for example the potential to use advanced fuels (with little or no tritium). This greatly reduces the complexity of the process and further reduces the residual radioactivity.  Inertial Fusion also allows for the use of flowing liquid wall chambers, thus overcoming a principal challenge: how to construct a chamber to withstand thermonuclear temperatures for the lifetime of a commercial reactor. In addition, Inertial Fusion allows for the direct conversion of the fusion products into electricity. This avoids the process of heating water, and so increases the net efficiency of the electricity generation process.

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  • There are already major laser projects underway, called NIF (in the USA) and LMJ (in France). Why build HiPER when NIF and LMJ exist?

The National Ignition Facility (NIF) and Laser Mégajoule (LMJ) are large facilities designed primarily for defence purposes. Only a small part of their mission is to investigate the science associated with energy generation. The method used in these facilities is not well suited to commercial power production.

HiPER will be a civilian facility whose main mission is to demonstrate that inertial fusion could be used as a future energy source. To do this it will use an all-optical method of energy generation called “fast ignition”.  This separates the process into 2 stages: fuel compression and fuel heating. This is analogous to a petrol engine (compression plus spark plug) approach. Fast ignition is predicted to require a much smaller laser to achieve high energy output, and so is far more compatible with a commercial power station’s requirements. 

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  • How long will it take to demonstrate this technique for power production?

Fusion ignition at NIF is expected to be demonstrated in the period 2010 to 2012.

The HiPER preparatory phase project is scheduled for 2008-2011, and so an informed decision on the route forwards can be taken by combining the results of the NIF demonstration with the detailed design work for HiPER.

Construction of HiPER would take ~5 years, and would require a precursor phase for detailed engineering design. As such, the facility is postulated to be built towards the end of next decade.

Following HiPER, one would need to develop a demonstrator reactor, and then move into commercial power plant production.  Thus, we are looking at mid-century for fusion power to make any significant impact on our electricity supply. This is why it is a solution for the long-term demand for abundant clean energy rather than a solution for the immediate-term climate change problem.

One possible future option will be to combine the work performed for HiPER with that of the wider international community (particularly the USA and Japan) to create a multi-regional approach to the next stage. Plans for this will be explored in the current phase of the HiPER project.

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  • Is the long term goal that fusion reactors will replace conventional nuclear power stations?

In the near term, conventional nuclear fission power stations will continue to be a part of the reduced carbon energy generation requirements. The technology is well developed and efficient and will continue to be a part of energy generation well into the future.

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  • Why is it taking so long to develop this technology?

Fusion is always 30 years away isn’t it?!

The expected achievement of net energy production using laser fusion (by the NIF facility in ~2010) changes the landscape, such that an accelerated programme can be initiated, based on solid scientific proof.

The reason that it’s taken 40 years to get to this point is because we needed to find a way to reliably produce extreme conditions in the laboratory. In order to obtain fusion the fuel must be heated to 100 million degrees Celsius. At these temperatures matter becomes a plasma (made from negatively charged electrons and positively charge nuclei). The plasma must be confined to keep the nuclei together long enough to undergo the fusion reaction. Confinement of plasma is a very difficult task as there cannot be contact of the plasma and vessel walls as firstly there are no materials that can withstand such temperature and secondly the plasma would quickly cool due to heat conduction. Instabilities in plasma are also a significant challenge as they can act negatively and cause energy losses or prevent confinement (depending on the method of confinement).

In the case of laser driven fusion the appropriate laser and fuel pellet technology for power stations must still be developed -  subjects that HiPER will address alongside the fusion physics.

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  • Is it dangerous? Will there be any radioactive waste products? If so, what will happen to them?

Only short lived radioactive products are produced.

The fusion process does produce neutrons and other high energy particles. These can interact with the reaction chamber and its immediate environment, such that over the course of the life of the fusion power plant radioactive waste is produced.  The level and nature of this is such that the waste stream is manageable – involving short-lived isotopes. Calculations suggest that it will take only 100 years to return a fusion power plant to brown field status, which is a perfectly acceptable position.

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  • What kind of science will be performed on HiPER?

The potential to access a wide range of exciting topics in fundamental physics is a principal driver for the HiPER project.

The science programmes were selected for their compelling nature in terms of delivering an extreme science capability to Europe. The HiPER facility specification was then developed to provide an internationally leading capability in these areas. The scope included:

  • Opacity and photoionization physics  - to address many outstanding fundamental atomic physics questions, along with their application to (for example) solar modelling.
  • Warm Dense Matter studies – addressing the principal outstanding regime of material science in which there is no accepted theory (for which HiPER will offer exceptional probing and diagnostic capability).
  • Laboratory Astrophysics – consistent with the fusion and high energy-density potential of HiPER, there is a wealth of astrophysical phenomena whose models could be tested in the laboratory, including supernovae evolution, proto-stellar jets, planetary nebulae, interacting binary systems, cosmic ray seeding and acceleration, and gamma-ray bursters.
  • Extreme Matter studies – What are the fundamental properties of matter in extreme states? This includes studies in Gigagauss magnetic fields (otherwise only found in highly compact stellar objects, and in which the magnetic field dominates the electric field in determining sub-atomic motion), in Gigabar pressure regimes, in radiatively dominated systems, in burning plasmas, etc.
  • Turbulence – how do compressible, nonlinear flows transition to turbulence and subsequently evolve? This is one of the few remaining fundamental uncertainties in classical physics.
  • Laser-plasma interaction physics – including the question of how waves and matter interact under highly nonlinear conditions
  • Nuclear physics under transient, excited state conditions – to study the effect of dense plasmas on nuclear cross sections, the behaviour of isomeric states via pump-probe studies of dressed states, and the creation of high density electron-position pair plasmas and the evolution of the ensuing pair-fireball.
  • Production and interaction of relativistic particle beams – for example, whether macroscopic amounts of relativistic matter can be created (then studied and utilised)
  • Fundamental physics at the strong field limit

It is clear that HiPER will open up entirely new areas of research, providing access to physics regimes which cannot be explored on any other science facility.
Full details of the science case are provided in the Conceptual Design Report.

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  • Is there a link between this facility and defence related work?

HiPER will be a civilian facility for energy research, with all the results published to the international scientific community. No aspect of the research undertaken on HiPER will be classified.  This has been a guiding principle of the project and a central aspect of the consortium from its inception

HiPER will investigate the science of “hot dense matter”. This lies at the centre of fusion research.  Aspects of laser driven fusion have been classified (although most of the field was declassified many years ago).  The remaining security concerns relate mostly to the use of x-ray radiation drive – the approach adopted by the National Ignition Facility (USA) and Laser Mégajoule (France). This is because of the analogy to x-ray radiation drive in thermonuclear weapons. The approach adopted by HiPER is fundamentally different. It will use a purely optical system, avoiding entirely the radiation interaction issues associated with the weapons research.  It is no coincidence that this is the laser fusion method being pursued in Japan, which strictly avoids any research into nuclear weapons.

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  • Where will HiPER be situated?

This is a decision for the current 3-year project. The UK is the coordinator of the project and the leading host country at the moment, but no decisions have been taken (in the UK or elsewhere) on construction or site selection yet.

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  • Who will pay for the facility?

This also is a decision for the current phase. One of the key outputs of this phase is the preparation of a consortium of nations and funding agencies willing to construct HiPER.

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