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2 Momentum spectrum at sea level of muons produced in cosmic rays. For energies above 1 GeV, the energy and the momentum of a muon are almost the same when expressed in GeV and GeV/c, respectively. Notice that this plot shows the muon flu multiplied by the muon momentum to the power of 2.7; the curve therefore peaks at a much larger value than the actual muon momentum spectrum. The angle indicated in the figur is the angle of the muon relative to the vertical direction. Figure by courtesy of the particle data group [6] in Chap. 1
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In 1895, Henri Becquerel discovered that some uranium salts emit penetrating radiation that can be made visible with ordinary
photographic emulsions. This discovery was the beginning of nuclear science. Today we know that most natural radioactivity
is due to a few very long-lived unstable isotopes that were formed 4.5 × 109 years ago. At that time...
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... corresponds to about 10 times the hadronic interaction length and 30 times the radiation length. A high-energy particle coming from outer space will always interact somewhere at high altitude in the atmosphere. In the collision, a large number of secondary particles will be produced, mainly protons, neutrons and pions. This is illustrated in Fig. 3.1. The secondary protons and neutrons will again interact, producing new secondary particles of lower energy and so on. Eventually, the energy is so low that particles are stopped by ionisation of the air molecules. The result is that protons and neutrons very rarely reach the Earth's surface. However, charged pions have a lifetime of ...
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... of lower energy and so on. Eventually, the energy is so low that particles are stopped by ionisation of the air molecules. The result is that protons and neutrons very rarely reach the Earth's surface. However, charged pions have a lifetime of 2.6 × 10 −8 s. The average distance travelled by a high-energy pion before it decays is given by Fig. 3.1 Artist's view of the interaction of a very high high-energy cosmic ray in the upper atmosphere and the subsequent production of secondary particles. Most of the time only muons, neutrinos and some low-energy gamma rays will reach the surface of the Earth. For the sake of clarity, the distance travelled by neutral pions is shown much ...
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... of these cosmic rays, everywhere on the Earth's surface there is a constant flu of muons. The intensity of this flu is of the order of 1/(cm 2 ·min). The energy spectrum of cosmic ray muons is shown in Fig. 3.2. These muons typically have a few GeV of energy, but the spectrum extends beyond 100,000 GeV. In addition to the muons, we will also see the end of the electromagnetic shower caused by gamma rays from neutral pion decay or by primary electrons. This will give electrons and gamma rays with energy rarely exceeding a few 10 MeV. ...
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... Cockcroft-Walton accelerator. The layout of a Cockcroft-Walton accelerator is illustrated in Fig. 3.3. The high voltage is generated with the circuit shown on the right-hand side of the figure This type of circuit is commonly used in many applications that need a high DC voltage source. It uses a voltage multiplier ladder network of capacitors and diodes to generate a high voltage. The principle is as follows: A moderately ...
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... is at a voltage below zero, a current will fl w through the diode, charging the point A to a positive voltage oscillating between 0 V and +2 V. The diode between point A and point B will then cause the charging of point B to the potential +2 V. The same scheme can then be repeated many times to reach higher and higher voltages, but eventually the Fig. 3.3 Working principle of a Cockcroft-Walton accelerator problems associated with very large electrostatic potentials will also limit this type of accelerator to ≈10 ...
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... Van de Graaff accelerator. A completely different approach to reach a high voltage is used in the Van de Graaff accelerator. This device looks like a 19th century electrostatic instrument, but it is still used today for accelerating ions. The working principle of a Van de Graaff accelerator is schematically shown in Fig. 3.4. The high-voltage electrode is a hollow sphere. A circular rubber band runs continuously between the high-voltage electrode and the low-voltage side of the accelerator. A high-voltage power supply of a few 10 kV at the low-voltage side of the accelerator provides the positive charge. The electric charges are generated by fiel emission ...
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... difficultie with very high voltages led Rolf Wideröe in 1928 to propose accelerating particles by using a lower voltage difference several times. The principle is illustrated in Fig. 3.5. A beam of particles passes through a succession of metallic tubes. The voltage difference between the tubes is changed while the particles are inside the tube, in such a way that the particles always see an accelerating fiel on passing from one tube to the next. Several accelerators using this principle were actually built, but the ...
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... obtain a more compact accelerator, in 1930 Lawrence proposed bending the particles into a circular path with a magnetic field In this way the same electrodes can accelerate the particles several times. The idea is illustrated in Fig. 3.6. The essential components of a cyclotron are a homogeneous and parallel magnetic fiel that forces the particles to travel in circles and an accelerating cavity in the shape of a pillbox cut into two halves. The two electrodes are called 'Dee's' because of their ...
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... of the magnetic fiel to understand how this is achieved. The fiel in the dipole will not be exactly constant and parallel. In the centre, the fiel will have the maximum value and it will decrease slowly from the centre towards the edge of the poles. As a result, the magnetic fiel lines cannot be exactly parallel, but must have a shape as shown in Fig. 3.7. To prove this let us consider the Maxwell equations in the integral form. The loop integral over the loop shown in Fig. 3.7 must be zero, since there is no current inside this loop. We therefore can write Fig. 3.7 The shape of the magnetic fiel lines in the gap between the pole pieces results in a focusing effect on the particles ...
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... the centre, the fiel will have the maximum value and it will decrease slowly from the centre towards the edge of the poles. As a result, the magnetic fiel lines cannot be exactly parallel, but must have a shape as shown in Fig. 3.7. To prove this let us consider the Maxwell equations in the integral form. The loop integral over the loop shown in Fig. 3.7 must be zero, since there is no current inside this loop. We therefore can write Fig. 3.7 The shape of the magnetic fiel lines in the gap between the pole pieces results in a focusing effect on the particles being ...
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... shows that the fiel lines must be bending outward as shown in Fig. 3.7. This shape of the fiel will have a focusing effect. This is made clear on the lefthand side of Fig. 3.7. The Lorentz force is always perpendicular to the magnetic fiel lines, while the centrifugal force always points radially outwards. In the mid-plane of the magnet, both forces exactly compensate, but away from the mid-plane, a ...
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... shows that the fiel lines must be bending outward as shown in Fig. 3.7. This shape of the fiel will have a focusing effect. This is made clear on the lefthand side of Fig. 3.7. The Lorentz force is always perpendicular to the magnetic fiel lines, while the centrifugal force always points radially outwards. In the mid-plane of the magnet, both forces exactly compensate, but away from the mid-plane, a small component towards mid-plane remains. To a good approximation, this restoring force is proportional to ...
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... RF frequency than at a large radius. If the particles are only making a small number of turns, we can get away with taking an average value for the RF frequency. Assume a particle starts its journey exactly in phase with the RF fiel as shown in Fig. 3.8. In the beginning, the particle will travel too fast and it will gradually be more and more early relative to the maximum of RF phase. However, at the same time, its trajectory will have a larger radius and the mismatch between the rotation frequency and the RF frequency will decrease. If the number of turns is not very large, the ...
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... this reason, most cyclotrons today have a very different focusing mechanism using a much more complicated magnetic fiel shape, namely, focusing with azimuthally varying fields In this design, the magnet is subdivided into azimuthal sectors with alternatively larger and smaller values for the magnetic field as shown in Fig. 3.9. In this figure darker sectors represent large values of the fiel and lighter sectors smaller values of the field In this fiel geometry, the particles no longer travel in circles, but according to a trajectory as shown in the figure The particle, therefore, acquires a periodically In addition, the sectors are also given a spiralling ...
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... this figure darker sectors represent large values of the fiel and lighter sectors smaller values of the field In this fiel geometry, the particles no longer travel in circles, but according to a trajectory as shown in the figure The particle, therefore, acquires a periodically In addition, the sectors are also given a spiralling shape as shown in Fig. 3.10. It is possible to show that this will further enhance the focusing effect on the beam. The focusing effect obtained with this azimuthal variation of the fiel is strong enough to compensate the defocusing effect due to a magnetic fiel that slightly increases with the radius. In this way, it is possible to make an isochronous ...
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... magnetic fiel deflect the positive proton in the opposite direction from the negative H -ion and therefore immediately ejects it from the magnet. 3.10 Pole pieces of the GANIL injector cyclotron. ...
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... with forced water-cooling, it is difficul to reach a magnetic fiel larger than ≈ 0.1 tesla. All magnets in accelerators therefore use a ferromagnetic yoke such that, for the same current, the fiel is increased by the relative magnetic permeability of the yoke material. The values of μ r for some commonly used ferromagnetic materials are shown in Fig. 3.13. Soft iron has μ r > 1000 and allows much larger field to be reached. However, in this case, the maximum fiel that can be reached is limited by the saturation of the ferromagnetic material. All ferromagnetic materials saturate at Fig. 3.13 Magnetic induction B versus μ 0 H in a solenoid with a ferromagnetic core. The quantity μ 0 H ...
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... of the yoke material. The values of μ r for some commonly used ferromagnetic materials are shown in Fig. 3.13. Soft iron has μ r > 1000 and allows much larger field to be reached. However, in this case, the maximum fiel that can be reached is limited by the saturation of the ferromagnetic material. All ferromagnetic materials saturate at Fig. 3.13 Magnetic induction B versus μ 0 H in a solenoid with a ferromagnetic core. The quantity μ 0 H is the magnetic induction that would exist in the solenoid in the absence of a ferromagnetic core. Armco and ST-35 are types of soft steel similar to the types of steel commonly used in magnets. Anhyster, often called mu-metal, is a ...
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... solution is the synchrotron and we now discuss this type of accelerator. Figure 3.14 shows the layout of a synchrotron. ...
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... frequency of the RF cavity should be equal to, or a multiple of, the revolution frequency of the particles. Figure 3.15 shows the fiel experienced by an electron passing through the RF cavity. ...
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... turn the machine just described into an accelerator, all that is necessary is to increase the magnetic fiel in the bending magnets very slowly. If the magnetic fiel is slightly increased, the trajectory of the particles is shorter and the particles come early relative to the 'stable point' and will again experience an accelerating Fig. 3.15 Phase of the particle relative to the RF phase in a synchrotron field The electrons acquire more energy and a new equilibrium is reached, but this time with a slightly higher energy for the electrons. We can again slightly increase the field the electrons will again acquire a higher energy, and so on. This can be continued until the ...
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... synchrotron we have just described is a 'weak focusing' synchrotron, and such machines have been used in the past. Modern synchrotrons, however, use a different focusing system called 'strong focusing'. Strong focusing is based on the use of quadrupole magnets such as shown in Fig. 3.16. A quadrupole magnet has four poles that are alternatively of north and south magnetic type. The beam passes through the magnet perpendicularly to the plane of the drawing and the centre of the beam passes through the centre of the magnet. From the geometry it is clear the magnetic fiel in the centre is zero. A few magnetic fiel lines ...
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... A quadrupole magnet has four poles that are alternatively of north and south magnetic type. The beam passes through the magnet perpendicularly to the plane of the drawing and the centre of the beam passes through the centre of the magnet. From the geometry it is clear the magnetic fiel in the centre is zero. A few magnetic fiel lines are drawn in Fig. 3.16. Let us assume that a beam of protons is passing through the quadrupole magnet shown in Fig. 3.16 from the front to the back. From simple inspection of the direction of the fiel lines, we see that the Lorentz force on the beam particles is focusing in the horizontal plane and defocusing in the vertical plane. With a correct shape of ...
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... passes through the magnet perpendicularly to the plane of the drawing and the centre of the beam passes through the centre of the magnet. From the geometry it is clear the magnetic fiel in the centre is zero. A few magnetic fiel lines are drawn in Fig. 3.16. Let us assume that a beam of protons is passing through the quadrupole magnet shown in Fig. 3.16 from the front to the back. From simple inspection of the direction of the fiel lines, we see that the Lorentz force on the beam particles is focusing in the horizontal plane and defocusing in the vertical plane. With a correct shape of the pole pieces of the magnet, the magnetic fiel will increase linearly with distance from the ...
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... very high-energy accelerators in use today are synchrotrons. The layout of these machines is similar to what is shown in Fig. 3.14, except that there are many more bending magnets and sets of quadrupole lenses are added between the bending magnets. The advantage of using quadrupoles is that a much stronger focusing effect on the beam is obtained. This will result in a larger particle flu and/or a smaller beam pipe diameter and therefore smaller magnets. This ...
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... the magnets are conventional magnets. Figure 3.17 shows a view of the inside of the tunnel housing the accelerator. ...
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... with the conditions k 1 R 0 = 2.405 and ω = kc this completes the solution of the problem. The shape of the corresponding electric and magnetic field is illustrated in Fig. 3.18. This mode of oscillation is referred to in the literature as the TM 010 mode. Here TM stands for 'transverse magnetic'. Clearly it should be understood that the true field are the real parts of the expressions above. For the TM 010 mode, the frequency of the oscillation is given by The symbol R 0 stands for the radius of the ...
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... its simplest geometry a linear accelerator hence consists of a series of aligned RF cavities as shown in Fig. 3.19. If each cavity has the maximum allowable length, the phase difference between two successive cavities must be equal to π . In the accelerating structure we must create a stationary wave with a phase difference of π between any two successive cavities. Sometimes one prefers to use shorter cavities Fig. 3.19 Very schematic ...
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... of aligned RF cavities as shown in Fig. 3.19. If each cavity has the maximum allowable length, the phase difference between two successive cavities must be equal to π . In the accelerating structure we must create a stationary wave with a phase difference of π between any two successive cavities. Sometimes one prefers to use shorter cavities Fig. 3.19 Very schematic representation of a standing-wave linear accelerator structure and in that case the phase difference between two successive cavities is less than π . This corresponds to an RF wave travelling along the ...
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... heat dissipation is due to Ohmic heating caused by the currents in the walls of the cavity. These currents can be found by considering the second Maxwell equation in the integral form over the loop shown as a dotted line in Fig. ...
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... the whole surface of the loop is zero, because the tangential component of the electric fiel is zero. Therefore, the magnitude of the current in the metal is equal to the magnetic fiel component parallel to the surface and the orientation of the current is perpendicular to this magnetic field Consider an infinitesima surface element dxdy as shown Fig. 3.20(B). The current fl wing through the surface element dxdy is given by J = Hdx and is fl wing in the y direction. This current will be restricted to a thin layer of thickness δ by the skin effect. The skin depth δ depends on the frequency f and on the resistivity of material. If ρ is the resistivity of the wall of the cavity, the resistance ...
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... accelerator. This accelerator is located near San Francisco, California, and it is the largest linear electron accelerator in the world today. The accelerating structures in this accelerator are of the travelling wave type and consist of a series of coupled oscillating cavities that support travelling waves. This structure is illustrated in Fig. 3.21. Inside each of the cavities there is an oscillating electromagnetic fiel with a geometry similar to what we discussed before. The oscillations in each cavity are coupled and the distance between the discs and the diameter of the iris adjusts the degree of coupling. This coupling determines the phase velocity along the ...
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... waveguides cannot be used for accelerating particles with a velocity much below the speed of light. If the particles travel at a few percent of the speed of light, each cavity becomes much shorter than its diameter, and it becomes difficul to avoid exciting other modes than the T 010 mode in the structure. A possible way to Fig. 3.21 (a) Geometry of the accelerating structure in an electron accelerator of the travelling wave type. (b) Cut away view of a section of the 'SLAC National Accelerator Laboratory' electron accelerator showing the internal structure Table 3.8 Main properties of the SLAC linear accelerator Length 3100 m Structure Iris-loaded wave guide Outer ...
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... slow ions is the structure shown in Fig. 3.22(a). In this geometry, there are a number of cavities, and around the beam there are drift tubes shielding the beam from the electric fiel when it has the wrong orientation. In such an accelerator the length of the drift tubes must vary to stay in step with the changing velocity of the particle. The shape of each cavity must ...
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... change in such a way that all the cavities oscillate at the same frequency. If the oscillations in the cavities are all in phase, the wall separating two successive cavities carries zero net current. This wall can therefore be omitted, leaving only bars to support the drift tubes. This is called an 'Alvarez structure', and it is shown in Fig. 3.22(b). In a linear accelerator with an Alvarez structure, a standing electromagnetic wave in a large conductive tube is created, with drift tubes in the centre containing the beam. Figure 3.23 shows the inside of an accelerating structure of the Alvarez type. This type of linear accelerator is often used as an injector for large proton ...
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... a linear accelerator with an Alvarez structure, a standing electromagnetic wave in a large conductive tube is created, with drift tubes in the centre containing the beam. Figure 3.23 shows the inside of an accelerating structure of the Alvarez type. This type of linear accelerator is often used as an injector for large proton synchrotron accelerators. ...
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... this the energy is sufficien for the beam to be injected into The most important recent advance in linear accelerator technology is the development of superconducting accelerating cavities. Figure 3.24 shows such a superconductive cavity working at 1.3 GHz. ...
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... the beam to be injected into The most important recent advance in linear accelerator technology is the development of superconducting accelerating cavities. Figure 3.24 shows such a superconductive cavity working at 1.3 GHz. It consists of nine sub-cavities and in each sub-cavity a standing wave with a fiel geometry similar to what is shown in Fig. 3.18 is generated. There is a phase difference of 180 • between any two successive cavities. If the centre-to-centre distance between two successive sub-cavities equals the distance travelled by a particle in one half period of the oscillation, a particle experiencing a maximum accelerating fiel in sub-cavity one, will again be in phase ...
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... magnet placed behind the target will remove the electrons and positrons, leaving only the gamma beam (see Fig. 3.25). This is the standard method for the production of gamma beams. This gamma beam will have a broad energy spectrum. By using suitable absorbers one can somewhat reduce the bandwidth of this ...
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... produces large amounts of electrons coming from the same point and all with about the same energy, i.e. almost zero energy. The result is that the number of positrons available for acceleration is many orders of magnitude smaller than the number of electrons and can only produce fairly low-intensity positron beams. To increase the intensity Fig. 3.25 Principle of the production of secondary gamma ray beams or positrons beams of the positrons, the particles are often kept in a storage ring. This is basically a synchrotron, but optimised for storing particles rather than for accelerating particles. Immediately after injection, the positrons fil the complete phase space of position ...
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... possible to produce beams with unstable particles such as pions, but because of their short lifetime it is impossible to store these particles in a storage ring. The intensity of such beams will therefore be many orders of magnitude lower than the intensity of proton beams. The principle of the production of secondary pion beams is illustrated in Fig. 3.26. To produce a beam of pions, a primary beam of protons is allowed to hit a solid target. A large number of secondary particles, mostly pions, are produced. With the help of bending magnets, collimators and quadrupoles, pions in a certain energy range are selected. To obtain a beam of muons, one starts from a beam of pions and keeps the ...
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... these secondary beams are available in the CERN accelerator complex shown in Fig. 3.27. In this accelerator complex, an RF-quadrupole accelerating section delivers protons of 750 keV. These protons are injected into a linear accelerator of the Alvarez type that brings the energy to 50 MeV. The protons are subsequently injected into a firs synchrotron, the PS-booster that accelerates them to 1.4 GeV. A second ...
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... rotating the beam one ensures that a maximum of radiation dose is delivered at the position of the tumour and a lower dose is delivered to the surrounding tissue. Figure 3.28(a) shows the general layout of an electron accelerator for this application. ...
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... is delivered at the position of the tumour and a lower dose is delivered to the surrounding tissue. Figure 3.28(a) shows the general layout of an electron accelerator for this application. If the beam energy is not very large, the accelerator has a modest size and it is possible to rotate it around the patient with a rotating gantry as shown on Fig. 3.28(b). If the energy of the electrons is larger, the accelerator is very bulky. It is better to have the accelerator in a fi ed position on the rotation axis of the gantry and steer the beam with magnets fi ed on the gantry as shown in Fig. 3.28(c). Figure 3.29 shows an example of an accelerating cavity used in this type of electron ...
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... has a modest size and it is possible to rotate it around the patient with a rotating gantry as shown on Fig. 3.28(b). If the energy of the electrons is larger, the accelerator is very bulky. It is better to have the accelerator in a fi ed position on the rotation axis of the gantry and steer the beam with magnets fi ed on the gantry as shown in Fig. 3.28(c). Figure 3.29 shows an example of an accelerating cavity used in this type of electron accelerators. Very similar accelerators are used for the purpose of sterilisation of food or other ...
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... is better to have the accelerator in a fi ed position on the rotation axis of the gantry and steer the beam with magnets fi ed on the gantry as shown in Fig. 3.28(c). Figure 3.29 shows an example of an accelerating cavity used in this type of electron accelerators. Very similar accelerators are used for the purpose of sterilisation of food or other materials. ...
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... or light ions such as carbon. The motivation of this method comes from the property of protons or heavy ions to have an increase of the energy loss by ionisation towards the end to the trajectory. In this case there is also no radiation damage behind the irradiated area. One therefore obtains a distribution of the radiation dose as shown on Fig. 3.30. This is particularly important if the area to be irradiated is close to a vital organ. The range of the hadrons in tissue should be up to about 30 cm, and this requires 220 MeV and 5280 MeV for protons and carbon ions, respectively. This energy can be reached either with a cyclotron or with a synchrotron, and systems of either type ...
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... energy can be reached either with a cyclotron or with a synchrotron, and systems of either type are in use in several places. Figure 3.11 shows a cyclotron for used proton therapy. ...
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... limited integrated beam flu obtainable with a synchrotron is not a problem in this application because only a small beam flu is needed. Figure 3.31 shows the layout of a typical synchrotron for radiation therapy. ...
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... spallation source provides the additional neutrons to sustain the nuclear chain reaction. Figure 3.32 shows that the optimal proton energy for this application is about 1 GeV. At this energy about 25 neutrons are produced for each proton incident on a heavy target such as lead. ...
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... in room temperature linear acceleration cavities is limited to about 1 MeV/m if we want to keep the power dissipation in the cavity walls at an acceptable level. Such a linear accelerator therefore will be more than 1 km long and will be too expensive. A possible solution is the use of superconducting linear accelerator structures as shown in Fig. 3.24. Such accelerating structures are used successfully in high-energy electron synchrotrons, such as synchrotron radiation sources. For particles travelling at a velocity close to the speed of light, average accelerating gradients of 25 MeV/m and conversion efficiencie of electrical power to beam energy as high as 50% have been ...
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... An igniter laser pulse forms a 'wire' of plasma in a plume of hydrogen gas; a heater pulse expands the wire to a plasma channel; the drive pulse accelerates bunches of electrons inside the channel to nearly uniform high energy. Figure by courtesy of Berkeley Lawrence Lab [16] illustrated in Fig. 3.33. The plasma, and the plasma wave, are caused by a powerful laser pulse in a low-pressure ...
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... international scientifi community agrees that the next high-energy accelerator to be built should be the International Linear Collider (ILC). This machine will be based on the use of superconductive accelerator cavities similar to the one shown in Fig. 3.24. The accelerating fiel will be 31.5 MeV/m. The main parameters of the ILC are summarised in Table 3.9. Such a machine could optimistically be operational by 2019. ILC will allow the study of electron-positron collisions with a centre of mass energy of 500 GeV. This seems modest compared to the LHC, but a proton is composed of ...
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... two accelerators and associated equipment could fi in a site 38 km long. Figure 3.34 shows the layout of the CLIC collider and Table 3.9 summarises its main properties. ...
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... Assume a linear accelerator as shown in Fig. 3.5 and an alternating voltage source of 10 MHz. Assume that we want to use it to accelerate electrons. After a few steps, the electrons will have a velocity close to the velocity of light. How long should each of the tubes be to accelerate each electron further? 2. Assume that you have a cyclotron with a magnet of 1.5 tesla field The ...
Citations
... While these devices have revolutionized communication and information exchange, concerns about potential radiation exposure have grown. The source of radiation in an environment could be natural or manmade (Tavernier, 2009;Mitrovic et al., 2020). Natural sources are the primordial radionuclides that exist inherently in different extents throughout earth's crust as well as the atmosphere and in all media in the environment or cosmogenic radionuclides such as 7 Be, 3 H, 14 C and 22 Na produced as when cosmic ray collide with atmospheric matter (Anjos et al., 2008;Gawad et at., 2023;Sanjay et al., 2024). ...
Some of the components of smart phones and computers, like ceramic capacitors may contain small amounts of radioisotopes. In this work, indoor and outdoor radiation exposure rates in Okutukutu “computer village” have been measured using the in-situ method. Ten indoor and ten outdoor readings were taken during working hours using a digital radiation meter. Standard equations and the Monte Carlo approach were used to analyze the data. The results show that mean exposure rates of 0.019 mRh-1 and 0.016 mRh-1 for indoor and outdoor respectively are not significantly high above the 0.013 mRh-1 world average. Approximately 700 and 90 people out of a population of one million (106) are expected to develop cancer as a result of indoor and outdoor exposure, respectively, according to the Monte Carlo simulation's assessment of minimum probable risk (P 5% = best case scenario). However, according to the maximum likely risk assessment results (P 95% = worst-case scenario), the estimated rates of cancer development from indoor and outdoor exposures are 480 and 2090, respectively, in a population of one million (106). Similar to this, the most likely risk calculation (50%) indicates that, out of a population of one million, 1320 and 270 people, respectively, are likely to acquire cancer as a result of indoor and outdoor exposure rates. Therefore, strict and efficient procedures must be implemented to protect both traders and buyers in the environments.
Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC) our research concentratesinassessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 under the scenario of normal operation using software package NRCDose72 provided by the USNRC. The database including the released radioactive nuclides, meteorology, terrain, population and agricultural production activities have beencollectedand processed to build the input data for the model calculation. The wind rose distribution obtained from the meteorological data in a five-year period from 2009-2013 showed that the radioactive nuclides released to environment spread in two main wind directions which are North East and South West. The XJQ (s/rrr') and DIQ (s/rrr') qualities which are, respectively, the ratio of activity concentration to release rateand that of deposition density of radioactive nuclides to release rate were calculated within an area of 80 km radius from the NPP site using XOQDOQ. Population doses were calculated using GASP AR. The XOQDOQ and GASP AR are two specific softwares in NRCDose72 package.
This study aims to present hypothetical nuclear and radiological event scenarios of a nuclear research reactor and a Cobalt-60 radiator at the region of Attica, Greece, through a local civil services perspective. The results aspire to present general mapping of consequences, while establishing a precise method of relevant incident management at Municipality level. Scenarios concerning the nuclear reactor have demonstrated vast results within the first 10 minutes - a necessary time frame to assess direct effects on human lives [1], which differentiate by wind speed, direction, terrain features and can influence areas about 10 km away from the reactor. To present these effects, risk maps were created for Municipalities of Northern Suburbs of Attica, based on data from scenarios and GIS tools. The Cobalt-60 radiator scenario has presented severe results mainly inside the facility hosting the radiator. Regarding protection levels of employees inside the facility, the use of HotSpot model has indicated a type of “average” protection that will mandatorily fulfill specific standards inside the facility. After quality research and bibliographical reference, we faced significant lack in briefing issues concerning local administrative bodies, when in parallel, administrative legal voids, basically legislative measures, were noted. Greek competent bodies, utterly unaware of those aspects, have proceeded to creation and implementation of specialized protection plans of public from radiological threats. On this basis a radiological incidents response plan was created for Municipalities that are affected on a medium scale. The aforementioned led to remarks and suggestions about facilitating response and prompt activation of Municipalities and citizens in the event of radiological and nuclear incidents.
