SUPA Accelerators Overview and Applications

SUPA Accelerators Overview and ApplicationsAimee HopperNovember 28, 20131 concisely describe the differences between the fol junior-gradeing ac-celerators and succumb their advantages and disadvantages(54 Marks)Accelerates Protons/Ions with a Kinetic Energy of 20-35 MeV.The work done on the ingredient is proportional to the voltage of the terminal. (W =qVterminal). The voltage of the terminal is dependent on the spinning top of the device (V _ kQL )where Q is the total confide of the motes, k is the Coulomb constant and L is the total length of the accelerating chamber, i.e. the total height of the device through which theion falls.Advantages genuinely simple to concur, and the principles behind the speedup ar really well undersas welld. subimputabled and cheap to maintainDisadvantagesvery difficult to draw off to very mettlesome-pitchedschool energies, as the nevertheless way to do so it so make a very high, stable structure.only allows one route for particles to tra vel.Betraton (6 Marks)Accelerates electrons with a kinetic push of 10-300 MeVThe betatron is a type of accelerator which uses an generate magnetic field to bucket along electrons to high energies in circular orbits. Uses solenoids with an electric automobile current passing through to produce bombastic magnetic handle to bend the particles.AdvantagesSimple design solenoids and their properties atomic number 18 well understood and grass easily be tested and manufactured.DisadvantagesRequires a huge amount of coils to get the induced magnetic fields required at that placefore very wakeless and damagely.As the coils arent superconducting, this system is excessively very lossy, and so wastes a pickle of postcode.Cyclotron (6 Marks)Figure 2 3Accelerates Protons/Ions with a kinetic zipper of 10 c MeV.A circular device which operates use large magnets to bend the particles. dickens semi-circular plates are tool-accessible to an AC source, applying a voltage across a crevice between the plates. This applied voltage causes the particle to accelerate. However, as in that location is also a large magnetic field present, the particle is constrained to bend its path as it accelerates, following a circular path. The lots heartiness the particle gets, the larger its radius becomes until eventually it is extracted from the device. (v = qBr m where q is the charge of the particle, B is the magnetic field strength applied across the plates, r is the radius of curvature of the particle and m is the citizenry of the particle.)AdvantagesThe same gap suffer be employ for all energies of particles, as the kick that is receive ordain always be in-phase with the kick produced by the AC source. This is because as the particles speed up, they have a bimestrial path, because take longer to arrive to the same point they were originally.DisadvantagesTo have a small device, large magnetic fields are required, which could pose a hassle to the set-up and cost of the project.As the particles become relativistic, the AC source lags behind, because not producing the patch up kick to the particles, possibly removing faculty from the system.Synchro-cyclotron (6 Marks)Accelerates Protons/Ions with a kinetic ability of 100-750 MeV surplus spirt of cyclotron takes into account relativistic lag from the AC sources.AdvantagesThere is no need for a narrow gap between the plates as in the case of conventional cyclotron, because strong electric fields for producing large acceleration are not required.So, only one plate is required kinda of two, the other end of the oscillating voltage supply being connected to earth.The magnetic pole pieces can be brought closer, thus making it executable to increase greatly the magnetic flux density.The frequency valve oscillator is able to procedure with much greater efficiency.DisadvantagesThe machine produces high energy ions with a comparatively low intensity.Synchrotron (6 Marks)Figure 3 ?Accelerates either electrons (kinetic energy of 1-10 GeV) or protons/ions (kinetic energy of 1-1000 GeV).Utilises a bod of different types of magnets dipoles (bend the send), quadrupole (focus the ray), sextupoles (account for chromaticity of the send out) etc.Uses RF cavities to bring in energy into the particle beam to account for synchrotron losses and increase the energy of the beamAdvantages burn generate a high luminosity beam at very high energies.The Synchrotron radiation lost can be used for other applications which require a very specific wavelength, such(prenominal) as medical applications.DisadvantagesSuffers from radiation lossesA synchrotron cannot use relativistic particles, as RF lag would become an issue.Storage ring (6 Marks)Accelerates electrons with a kinetic energy of 1-7 GeV European Synchrotron Radiation Facility.A storage ring is a particle accelerator that keeps a particle beam at a accepted energy for a long period of time. This is useful, especially in synchrot rons, as the beam can be kept at a certain energy ensuring that a specific frequency is emitted in the form of radiation.AdvantagesStores a particle beam at a certain energy, so dont have to increase beam energy from 0 (time consuming).DisadvantagesSystems have to be very precise and stable costlyCollider ring (6 Marks)Accelerates electrons (kinetic energy of 10-100 GeV) or protons/ions (kinetic energy of 1-7TeV Large Hadron Collider).Particles of a particular energy are injected into the ring and stored there until they are obligate to collide at set points throughout the structure.AdvantagesCan reach higher energies than in a LINAC at much lower cost due to giving each beam half(prenominal) the required centre of mass energy.if using particle-antiparticle, then the same equipment will accelerate the two beams in opposite directions (due to difference in charge)Disadvantages place pipe needs to hold 2 beams, which need to only move with each other when required need very accur ate equipment to checker beam stays separated.Linacs (6 Marks)Accelerates electrons (kinetic energy of 20 MeV to 50 GeV) or protons/ions (kinetic energy of 50-800 MeV Los Alamos Meson Physics Facility)A Linear Accelerator accelerates the particle beam along a straight line as opposed to a circular path.AdvantagesNo energy loss due to particles accelerating in a curve.Can accelerate heavy ions to far higher energies than possible in the circular accelerators.Can produce a continuous stream of particles as opposed to bunched particles present in circular accelerators.DisadvantagesNeed to be very long to get up to high energies.A high number of AC driver sources are required, which is both costly and introduces possible errors due to out-of-phase issues.Linear collider (6 Marks)Accelerates electrons from 50-1000 GeV.A linear collider is used to collide particles in a straight line towards one another.AdvantagesNo energy needs to be pumped into the beam to account for radiation losses. beams will never be able to interact with each other before the collision points, therefore can use smaller beam pipes.can accelerates heavier particles since they dont need to be bent.DisadvantagesFor collisions with the highest possible energy, two linacs producing beams with the same energy headed towards each other, the complete machine would need to be very long2 Explain the advantages of using a collider rather thana single beam for collision experiments. adorn youranswer by con postring 7 TeV proton beams. (10 Marks)By using 7 TeV proton beams in a collider, a centre of mass energy of 14 TeV can be achieved by sending both beams in opposite directions to collide. This is seemingly very useful when probing matter, as a higher energy will effect in higher mass particles / more low mass particles being produced, therefore available for analysis. The single beam would only be able to reach 7 TeV, and so has a readyed range by comparison to the collider.To obtain a centre of mass energy of 14 TeV in a single beam is also incredibly difficult to produce, both due to the cost and the size of the equipment required. thus a 14 GeV beam isnt feasible to produce. Whereas 7 TeV is relatively easy. Also, when 14 GeV does become easy to produce, a centre of mass energy of 28 GeV would then be possible, which is far more attractive for high energy energy studies.3 Explain briefly how a optical maser- blood plasma wakefield acceleratorworks. What determines the limit in energy for a uniformplasma density? (13 Marks)In optical maser-plasma wakefield acceleration, a laser thrill is used to excited very high electric fields in a following plasma wave. effective energy transfer is made between laser pulse and plasma wave if both the wave and the pulse are travelling at the same speed, with a high energy gain being getable in low-density plasmas, in which the phase velocity of the laser-plasma is equal to the laser pulse group velocity, which is very close to the speed of light. This allows the longitudinal electric fields associated to the fast plasma wave to accelerate relativistic particles inwardly the plasma, and can even trap the particles to the electrostatic wave. This allows particles to be boosted to very high energies in a very short distance.It is important that the density of the plasma is below the critical density (nc =11 _ 1021=_20_m)5We know that the utmost energy of a wave is related to the 2g of the wave by the equatingE _ epn _1g (1)where g is the lorentz factor associated with the group velocity of the laser pulsewhich is equal tog =0p (2)So the more thick-skulled the plasma, the lower g is, and therefore the slower the wave travels. If the wave travels too slowly, then the particles will move away from the wave faster.4 Briefly describe how a FEL and synchrotron radiationsource works. What is the advantage of a free-electronlaser? (10 Marks)A free-electron laser utilises both undulator and radiation fields to produc e ponderomotive (essentially a light-radiation pressure) on the particles. This forces the electrons to oscillate at the fundamental frequency. If the electrons can be forced to bunch together on a wavelength scale ( pop offn by equating 3), then the electrons emit coherently._ =_u22_1 +a2u2_ (3)Synchrotron radiation works by accelerating a particle in a circular path, therefore producing radiation. This generally gives an incoherent beam of radiation, as any discrepancies in the individual particle energies will result in a slightly different frequency radiation culmination o_. It is caused by undulators, wigglers and bending magnets, and due to the high speeds of the particles, comes out the acceleration device in a cone, with an opening angle equal to _1 .The benefits of the free-electron laser are that it produces a much higher brightness due to the coherence of the wave, therefore producing a significantly higher photon flux for a given energy, as compared to the synchrotron.S ynchrotrons before long produce an average brilliance of 1011. The FEL is able to produce a brilliance of up to 6 orders of magnitude higher, however there are currently issues with regards creating coherence throughout the whole length of the laser pulse.5 Describe how particles and X-rays can be used to treat crabby person and give the advantages and disadvantages of thedifferent radiation types used for radiotherapy. (13 Marks)With regards to cancer, the aim is to damage or annihilate the DNA of the neoplasm to kill it by disrupting the cell cycle of the tumour in one way or another. roentgen rays produced in 5-20 MeV linacs are currently used to treat most patients. They can cure up to 45% of cancers, 50% of which is by radiation therapy alone, or combined with chemotherapy and/or surgery.This is achieved by using 3D Conformation therapy, where multiple X-Rays are used to compact the beam energy onto the tumour, whilst minimising the damage caused to surrounding cells.Particl es that can be used to treat cancers include electrons (positrons), protons, neutrons and ions. These can either be used directly, or can help in producing radio-isotopes to also assist in treating cancer through Positron Emission Tomograohy (PET) or Single Photon Emission Computed imaging (SPECT).If used directly, then the particles are _red at the tumour. Charged particles interact with electrons in the body, and a vast majority of the energy of the particle is deposited according to its Bragg aggrandisement (energy loss vs distance plot of the Bethe-Bloch formula).The aim is to get this depth to contain to that of the tumour, so the energy deposited causes maximal damage to the cancer whilst causing very little damage to surrounding tissue.The advantages of particle therapy areAll (most) energy deposited where required, with little to no damage of surrounding cells.Very few side effectsSeems to have a higher cure rate with certain types of cancers (i.e. uveal melanoma).Massive ly reduces the damage done to children sufferers as less of their hale tissue is effected, reducing the chances of side-effects caused by traditional methods.Particles can be accelerate to whatever energy is required to reach the tumour.The disadvantages of particle therapy areIt requires a huge capital investment, and is massively expensive by comparison to X-Ray treatments.Requires hospitals to have room for a large particle accelerator to accelerate the ions, which isnt always possible.Expensive to run, due to energies required.References1 http//www.lbl.gov/abc/wallchart/chapters/11/2.htmlas viewed on the 25/11/132 http//commons.wikimedia.org/wiki/FileWideroe linac en.svgas viewed on the 25/11/133 http//images.yourdictionary.com/cyclotronas viewed on the 25/11/134 http//www.schoolphysics.co.uk/age16-19/Nuclear physics/Accelerators/text/Synchrotron /index.htmlas viewed on the 25/11/135 V. Malka, J. Faure, Y. Glinec, A. Lifschitz, LASER-PLASMA WAKEFIELD AC-CELERATION CONCEPTS, TES TS AND PREMISES, EPAC, 2006