Category: A Level Physics Chapters

France expands nuclear power plans despite Fukushima

BBC News Update……… People look at the construction site of the third-generation European Pressurised Water nuclear reactor (EPR) in Flamanville, north-western France, in this file picture taken in April 2011

With dwindling fossil fuel supplies, France is increasingly reliant on its nuclear power plants which now provide it with three-quarters of its electricity

In the aftermath of Japan’s nuclear crisis at Fukushima, some European nations are rethinking their atomic plans. But France, home to 58 of 143 reactors in the EU, remains nuclear energy’s champion, and plans not to retire its power stations but to expand them. Emma Jane Kirby examines why.

For many tourists visiting the tranquil north Normandy coast, the giant EPR reactor at Flamanville is little more than a lamentable industrial scar on a rather beautiful landscape.

But to the French government, Flamanville’s European Pressurised Reactor (EPR) is the embodiment of the future.

Following the disaster at Japan’s Fukushima nuclear power station – which was heavily damaged by the deadly 11 March quake and tsunami – President Nicolas Sarkozy announced there would be an audit of all nuclear facilities.

But he added firmly that France would not be rethinking its nuclear energy policy as neighbours Germany, Italy and Switzerland have.

Unlike Germany’s reversal of policy on Monday that will see it phase out the country’s 17 nuclear power stations by 2022, Mr Sarkozy said France was confident that nuclear energy was safe and it was “out of the question” to end nuclear power.

The EPR being constructed in Flamanville is marketed as the most secure power station yet.

A protester wearing a gas mask stands in front of the construction site of the third-generation European Pressurised Water nuclear reactor (EPR) in Flamanville, during an anti-nuclear demonstration, on 23 April, 2011Anti-nuclear protesters have made their thoughts about the Flamanville expansion abundantly clear. It is built by EDF, a company which is 80% owned by the French government. The system is organised into four sub-systems (current plants in operation only have two), each located in separate rooms away from the reactor building.

Simultaneous failure of the systems is regarded as almost impossible; the idea is that if an incident were to occur on one of the systems, the reactor could continue to operate safely during repairs, as at least two other systems would remain available.

In the event of a meltdown, the core would be isolated by the reactor building’s dual-wall containment which has one wall in pre-stressed concrete designed to withstand significant increases in pressure, and the second in reinforced concrete, known as the concrete shell. But many French people – including Didier Anger, an anti-nuclear campaigner and former MEP – are not convinced.

Tsunami breaching the power plant's defences (Image: TEPCO)Fukushima was heavily damaged by the 11 March quake and tsunami. “That’s just propaganda,” Mr Anger told the BBC at his home a few miles inland from Flamanville. He pointed to the strong ties between EDF and the French government and asked how we could trust the government’s word about nuclear safety when it owns such a massive stake in the company that builds the reactors? It was all, he insisted, the “same club”.

“France claims to be a democracy,” he laughed. “But in terms of the nuclear industry we are yet to prove that! “A few weeks ago, after Fukushima, the current director of our nuclear safety authority announced in front of MPs that perhaps we should stop the EPR reactor to look at any possible problems.

“A few hours later he was made to back-pedal… he was silenced… because the power of the old boys’ network is formidable in France.”

Two years ago, cracks were found in the concrete base of the reactor dome at Flamanville and welding proved to be sub-standard. Addressing those safety issues has meant the project is now at least two years behind schedule and way over budget.

This week, European nuclear watchdogs must start safety checks – or stress tests – on their nuclear facilities to make sure they could withstand an earthquake or tsunami like that at Fukushima. Although a 9m (30 ft) wave is unlikely on the North Normandy coast at Flamanville, Prof Jacques Foos, one of France’s most respected nuclear scientists, says all precautions must be taken. “The accident at Fukushima proved completely extraordinary events can happen,” he told me. “So what would happen if a giant wave did hit one of our nuclear power plants? We need to check that out. “I’m not saying we need to think about every eventuality such as what would happen if we were struck by a meteorite… but I am saying that when we build nuclear power plants now, we have to think the unthinkable.” The high-tech EPR reactor at Flamanville has been designed to withstand disasters such as a plane crash – but older reactors will not have such sophisticated security systems. Claude Birraux, an MP with President Sarkozy’s governing UMP party, has been chairing the official French parliamentary inquiry into the Fukushima accident, and hopes that the EU stress tests coupled with the separate French audit will help to reassure a nervous French public.

Environmentalist group Greenpeace activists are suspended next to protest banner on one of the cooling towers of the nuclear plant of Belleville-sur-Loire, central France, in March 2007Critics say businesses are scared off by the EPR reactor

“There will be a review made by the safety authorities and if one nuclear power plant is not able to answer to those questions (set by the EU), it can maybe be shut down,” he said. “Maybe.”

Nuclear technology is one of France’s major exports. Three years ago, France struck a deal with the UK to build four new EPR reactors in Britain but in December 2009 it lost a $40bn (£24bn) reactor deal with Abu Dhabi amid recriminations that it was too costly.

President Sarkozy insisted that the deal was lost because its high safety standards drove up the cost. Professor Jacques Foos hopes that in a post-Fukushima world its “safety first” EPR reactors will bring in more business for France. “We will see a boost in sales now,” he said confidently. “Because who would baulk at paying for safety these days? You can’t have a reactor these days that’s thought of as being too safe.” A boost in sales should result in a boost in jobs but that’s not an argument that holds much sway with anti-nuclear campaigner Didier Anger. Building on a second EPR reactor on the Normandy coast at Penly begins next year but Mr Anger doubts it will boost employment.

“In Flamanville, we thought the EPR would bring a lot of employment… but 50% of the workers are from Poland or Romania, or at least not from here,” he complained. He pointed to the high 9.7% unemployment rate in the Cherbourg area and asked me why I thought the jobless total was so high. “It’s because a lot of businesses are scared off by the EPR reactor,” said Mr Anger. “They think what if there was an accident? The exclusion zone would be 20km [12 miles] or more. That’s no good for business… so they don’t set up here.”

Nuclear landscape? But if France is to make more sales with the EPR reactor, who will the new customers be when most of Europe appears to be pulling out of the nuclear energy game and mothballing their old reactors? Could nuclear technology be sold to countries which simply aren’t ready to deal with the potential risks?

Chernobyl's Number Four Reactor - 20 April 2011Memories of the disaster at Chernobyl linger in France quarter of a century later. MP Claude Birraux insists that France will only sell nuclear technology to responsible countries. “There are three rules: safety, safety and safety, whatever the cost,” he said. “You need to have regulation, legislation and you need an independent safety authority… otherwise no… you can’t have it.”

France began developing its civilian nuclear programme as a response to oil shortages in the 1970s. With dwindling fossil fuel supplies, the country is increasingly reliant on its nuclear power plants which now provide it with three-quarters of its electricity.

Nuclear energy, said Claude Birraux, was essential for “French independence”. With 58 nuclear reactors already in operation here, sites like Flamanville look likely to be part of the French landscape for many years to come.

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Institute of Physics Brimingham Lecture Series

All Physics students should try and get to at least one of these lectures if possible this year. 

Please note that tea and coffee will be provided from 7 pm in the Tea Room of the Poynting building.

Tickets for the Christmas lectures can be obtained free of charge from

[email protected]  or by writing to Lynne Long , School of Physics and Astronomy, The University of Birmingham, B15 2TT

The lecture programme can also be found here…

Up to date details and maps of the University can be found on the University web site

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LHC results put supersymmetry theory ‘on the spot’

This is a great article which shows the process of having a theory and then trying to prove it, even if the experiement is huge!

Supersymmetry fails to predict the existence of mysterious super particles.

SupersymmetryResults from the Large Hadron Collider (LHC) have all but killed the simplest version of an enticing theory of sub-atomic physics. Researchers failed to find evidence of so-called “supersymmetric” particles, which many physicists had hoped would plug holes in the current theory. Theorists working in the field have told BBC News that they may have to come up with a completely new idea. Data were presented at the Lepton Photon science meeting in Mumbai.

They come from the LHC Beauty (LHCb) experiment, one of the four main detectors situated around the collider ring at the European Organisation for Nuclear Research (Cern) on the Swiss-French border.

According to Dr Tara Shears of Liverpool University, a spokesman for the LHCb experiment: “It does rather put supersymmetry on the spot”.

There’s a certain amount of worry that’s creeping into our discussions”

Dr Joseph Lykken Fermilab

The experiment looked at the decay of particles called “B-mesons” in hitherto unprecedented detail. If supersymmetric particles exist, B-mesons ought to decay far more often than if they do not exist. There also ought to be a greater difference in the way matter and antimatter versions of these particles decay.

The results had been eagerly awaited following hints from earlier results, most notably from the Tevatron particle accelerator in the US, that the decay of B-mesons was influenced by supersymmetric particles. LHCb’s more detailed analysis however has failed to find this effect.

Bitten the dust

Lead ion collisionsThis failure to find indirect evidence of supersymmetry, coupled with the fact that two of the collider’s other main experiments have not yet detected supersymmetic particles, means that the simplest version of the theory has in effect bitten the dust. Collisions inside the LHC should have found some evidence of Supersymmetry by now. The theory of supersymmetry in its simplest form is that as well as the subatomic particles we know about, there are “super-particles” that are similar, but have slightly different characteristics. The theory, which was developed 20 years ago, can help to explain why there is more material in the Universe than we can detect – so-called “dark matter”. According to Professor Jordan Nash of Imperial College London, who is working on one of the LHC’s experiments, researchers could have seen some evidence of supersymmetry by now. “The fact that we haven’t seen any evidence of it tells us that either our understanding of it is incomplete, or it’s a little different to what we thought – or maybe it doesn’t exist at all,” he said. Disappointed the timing of the announcement could not be worse for advocates of supersymmetry, who begin their annual international meeting at Fermilab, near Chicago, this weekend.


“Supersymmetry… has got symmetry and its super – but there’s no experimental data to say it is correct” said Professor George Smoot Nobel Laureate

Dr Joseph Lykken of Fermilab, who is among the conference organisers, says he and others working in the field are “disappointed” by the results – or rather, the lack of them. “There’s a certain amount of worry that’s creeping into our discussions,” he told BBC News. The worry is that the basic idea of supersymmetry might be wrong.

“It’s a beautiful idea. It explains dark matter, it explains the Higgs boson, it explains some aspects of cosmology; but that doesn’t mean it’s right. “It could be that this whole framework has some fundamental flaws and we have to start over again and figure out a new direction,” he said. Experimental physicists working at the LHC, such as Professor Nash, say the results are forcing their theoretical colleagues to think again. “For the last 20 years or so, theorists have been a step ahead in that they’ve had ideas and said ‘now you need to go and look for it’. “Now we’ve done that, and they need to go scratch their heads,” he said.

That is not to say that it is all over for supersymmetry. There are many other, albeit more complex, versions of the theory that have not been ruled out by the LHC results. These more complex versions suggest that super-particles might be harder to find and could take years to detect. Some old ideas that emerged around the same time as supersymmetry are being resurrected now there is a prospect that supersymmetry may be on the wane. One has the whimsical name of “Technicolor”. According to Dr Lykken, some younger theoretical physicists are beginning to develop completely novel ideas because they believe supersymmetry to be “old hat” . “Young theorists especially would love to see supersymmetry go down the drain, because it means that the real thing is something they could invent – not something that was invented by the older generation,” he said.

And the new generation has the backing of an old hand – Professor George Smoot, Nobel prizewinner for his work on the cosmic microwave background and one of the world’s most respected physicists. “Supersymmetry is an extremely beautiful model,” he said. “It’s got symmetry, it’s super and it’s been taught in Europe for decades as the correct model because it is so beautiful; but there’s no experimental data to say that it is correct.”

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UK’s atomic clock ‘is world’s most accurate’

This is an article from BBC Science, really useful for how we work out units!

By Jason Palmer Science and technology reporter, BBC News, Teddington

Caesium clock at NPL (NPL)An atomic clock at the UK’s National Physical Laboratory (NPL) has the best long-term accuracy of any in the world, research has found.

Studies of the clock’s performance, to be published in the journal Metrologia, show it is nearly twice as accurate as previously thought.

The clock would lose or gain less than a second in some 138 million years.

The UK is among the handful of nations providing a “standard second” that keeps the world on time.

However, the international race for higher accuracy is always on, meaning the record may not stand for long.

The NPL’s CsF2 clock is a “caesium fountain” atomic clock, in which the “ticking” is provided by the measurement of the energy required to change a property of caesium atoms known as “spin”.

By international definition, it is the electromagnetic waves required to accomplish this “spin flip” that are measured; when 9,192,631,770 peaks and troughs of these waves go by, one standard second passes.

Matching colours

Inside the clock, caesium atoms are gathered into bunches of 100 million or so, and passed through a cavity where they are exposed to these electromagnetic waves.

The colour, or frequency, is adjusted until the spins are seen to flip – then the researchers know the waves are at the right frequency to define the second.

The NPL-CsF2 clock provides an “atomic pendulum” against which the UK’s and the world’s clocks can be compared, ensuring they are all ticking at the same time.

That correction is done at the International Bureau of Weights and Measures (BIPM) in the outskirts of Paris, which collates definitions of seconds from six “primary frequency standards” – CsF2 in the UK, two in France, and one each in the US, Germany and Japan.

For those six high-precision atomic pendulums, absolute accuracy is a tireless pursuit.

At the last count in 2010, the UK’s atomic clock was on a par with the best of them in terms of long-term accuracy: to about one part in 2,500,000,000,000,000.

What time is it, exactly?

World clock

  • The international time standard is maintained by a network of over 300 clocks worldwide
  • These are sent by satellite and averaged at BIPM, a measurement institute in France
  • But the “tick” of any one of them could drift out of accuracy, so BIPM corrects the average using six “primary frequency standards” in Europe, the US and Japan
  • Their corrected result, “International Atomic Time”, is occasionally compared with the time-honoured measure of time by astronomical means
  • Occasionally a “leap second” is added or subtracted to correct any discrepancy

But the measurements carried out by the NPL’s Krzysztof Szymaniec and colleagues at Pennsylvania State University in the US have nearly doubled the accuracy.

The second’s strictest definition requires that the measurements are made in conditions that Dr Szymaniec said were impossible actually to achieve in the laboratory.

“The frequency we measure is not necessarily the one prescribed by the definition of a second, which requires that all the external fields and ‘perturbations’ would be removed,” he explained to BBC News.

“In many cases we can’t remove these perturbations; but we can measure them precisely, we can assess them, and introduce corrections for them.”

The team’s latest work addressed the errors in the measurement brought about by the “microwave cavity” that the atoms pass through (the waves used to flip spins are not so far in frequency from the ones that flip water molecules in food, heating them in a microwave oven).

A fuller understanding of how the waves are distributed within it boosted the measurement’s accuracy, as did a more detailed treatment of what happens to the measurement when the millions of caesium atoms collide.

Without touching a thing, the team boosted the known accuracy of the machine to one part in 4,300,000,000,000,000.

But as Dr Szymaniec said, the achievement is not just about international bragging rights; better standards lead to better technology.

“Nowadays definitions for electrical units are based on accurate frequency measurements, so it’s vital for the UK as an economy to maintain a set of standards, a set of procedures, that underpin technical development,” he said.

“The fact that we can develop the most accurate standard has quite measurable economic implications.”

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KS3-5 Waves Animation

This animation acts as a simple virtual oscilloscope with explainations and calculations on wavelength….

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Eureka Physics Videos (New)

This set of videos are out of print but original copyrights to KOCE have been preserved as a set to show how Physics used to be explained to Y7 -> 13 and still should be!


Unit 1: Force and Energy

  1. Inertia
    This program introduces the series and sets forth the concept of inertia, the first law of physics. Things like to keep on doing what they’re already doing.
  2. Mass
    Building on the concept of inertia, Eureka! Adds the factor of mass, tells how it’s measured and show how it differs from size. Concept: Inertia increases with mass.
  3. Speed
    The concept of speed is introduced to the inertia-mass relationship. Concept: Force varies with mass and rate of change of speed.
  4. Acceleration 1
    With the examples of a bicycle and a baseball player, an important rule of physics becomes apparent. Concept: Force = mass x acceleration.
  5. Acceleration 2
    An animated locomotive helps explain how acceleration works and is calculated. The importance of reasonable units is stressed. Concept: Acceleration = m/s2.
  6. Gravity
    Isaac Newton’s celebrated falling apple is cited to explain the force of gravity and the unit with which the force of gravity is measured. Concept: Force of Gravity = Mass x 10 m/s2.
  7. Weight vs Mass
    Eureka! Explains the difference between weight and mass and shows how only mass is the same on the moon and on the earth.
  8. Work
    A circus strongman and a clown help present the physics definition of work. Concept: Work = force x distance.
  9. Kinetic Energy
    Animated billiard balls help demonstrate kinetic energy-the energy of motion.
  10. Potential Energy
    A rock teetering on the edge of a cliff is shown to have potential energy-the energy of position.

Unit 2: Simple Machines

  1. The Inclined Plane
    This program demonstrates how an inclined plane allows you to trade increased distance for decreased force.
  2. The Lever
    Eureka! Demonstrates the principle of the lever; “The longer the arm of the lever to which force is applied, the less that force need be”.
  3. Mechanical Advantage and Friction
    Professors A and B compare the mechanical advantage of an inclined plane with that of a lever.
  4. The Screw and the Wheel
    This program provides examples and definitions of a screw and a wheel: a screw is simply a twisted inclined plane, a wheel is simply a circular lever, whose fulcrum has become an axle.
  5. The Pulley
    Eureka! shows viewers how a pulley works to lift a heavy object. If you double the number of ropes supporting the weight, you double the mechanical advantage.

Unit 3: Heat and Temperature

  1. Molecules in Solids
    This program defines the three states of matter, and illustrates the latticework pattern of molecules in solids. Viewers learn the origin of the word “molecule”.
  2. Molecules in Liquids
    A molecules in a solid get hotter, they vibrate faster and faster and eventually slip out of their latticework pattern. When this occurs, the substance melts, changing from a solid to a liquid state.
  3. Evaporation and Condensation
    A goldfish bowl filled with water demonstrates the process of evaporation in which speeding molecules escape from a liquid to form a gas.
  4. Expansion and Contraction
    Using balloons to illustrate the process, Eureka! shows how, when matter gets hot, it’s molecules go faster and the solid, liquid or gas expands. Conversely, when matter gets cold, it’s molecules go slower and the solid, liquid or gas contracts.
  5. Measuring Temperature
    Eureka! shows viewers how Swedish scientist Anders Celsius invented the Celsius thermometer using the expansion of mercury as a measure of temperature.
  6. Temperature vs Heat
    Eureka! explains that heat refers to quantity of hotness, and is determined by the mass and speed of molecules. This program demonstrates that a bucket of water at temperature of 50 degrees Celsius contains more heat than a cup of water at 100 degrees Celsius.

Unit 4: The Conduction of Heat

  1. Atoms
    This program explains that molecules are made up of atoms. In pure metals, all the atoms are arranged separately in a latticework patter, but in most nonmetals, liquids, and gases the atoms are bunched together into molecules.
  2. Electrons
    Using an animated model of an atom, Eureka! illustrates how electrons whiz so quickly round the nucleus that they appear to form layers.
  3. Conduction
    Eureka! looks at the process of conduction, explaining that the application of heat to an object makes the molecules or atoms vibrate faster and cause a short of “domino effect”.

Unit 5: The Convection of Heat

  1. Volume and Density
    This program explains that volume refers to the amount of space an object envelops and that density refers to the amount of mass that is compacted in a given volume.
  2. Buoyancy
    Showing viewers that objects immersed in a liquid are buoyed up by a force equal to the weight of the liquid displaced, this program explains the principle of buoyancy.
  3. Convection
    This program explains how the principle of buoyancy is responsible for the process of heat transfer called convection.
  4. Heat as Energy
    Heat is produced whenever there is movement and friction between two objects. Since movement is a form of energy, it follows that heat must also be a form of energy.
  5. Radiation Waves
    Viewers learn that one of the chief ways in which heat energy moves is in the form of waves. This kind of heat transfer is called radiation.
  6. The Radiation Spectrum
    Viewers learn that the waves of heat energy radiated by the sun come in many forms which together make a band, or spectrum of energy waves.

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SI Units…

Here are some basic SI units that you might want to use in your calculations….

quantitynamesymbolin terms of …
other unitsbase units
plane angleradianrad m m−1
solid anglesteradiansr m2 m−2
frequencyhertzHz s−1
forcenewtonN m kg s−2
pressure, stresspascalPaN/m2m−1 kg s−2
energy, work, heatjouleJN mm2 kg s−2
power, heat flowwattWJ/sm2 kg s−3
electric chargecoulombC s A
electric potentialvoltVW/Am2 kg s−3 A−1
capacitancefaradFC/Vm−2 kg−1 s4 A2
resistanceohmΩV/Am2 kg s−3 A−2
conductancesiemensSA/Vm−2 kg−1 s3 A2
magnetic fluxweberWbV sm2 kg s−2 A−1
magnetic flux densityteslaTWb/m2kg s−2 A−1
inductancehenryHWb/A m2 kg s−2 A−2
celsius temperaturedegree celsius K
luminous fluxlumenlmcd srm2 m−2 cd
illuminanceluxlxlm/m2m−2 cd
radioactivitybecquerelBq s−1
absorbed dosegrayGyJ/kgm2 s−2
equivalent dosesievertSvJ/kgm2 s−2
catalytic activitykatalkat s−1 mol

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