Chapter 3 Basic Instrumentation for Nuclear Technology Outline of experiment 1. Accelerators get particles(e.g. protons,.) 2. Detectors accelerate them throw them against each other observe and record what happens 3. Reactors analyse and interpret the data
Chapter 3. Basic Instrumentation for Nuclear Technology 1. Accelerators 2. Detectors 3. Reactors Outline of experiment: • get particles (e.g. protons, …) • accelerate them • throw them against each other • observe and record what happens • analyse and interpret the data
1. Accelerators History-Why Particle sources Acceleration stage Space charge Diagnostics Application
• History-Why • Particle Sources • Acceleration stage • Space charge • Diagnostics • Application 1.Accelerators
Natures particle accelerators Examples from the nature electrostatic discharge a and B-decays, cosmic rays Naturally occurring radioactive sources Up to 5 Mev alpha's(helium nuclei) Up to 3 Mev Beta particles ( electrons) Natural sources are difficult and limited Chemical processing: purity messy, and expensive Low intensity Poor geometry Uncontrolled energies, usually very broad
Nature’s Particle Accelerators • Naturally occurring radioactive sources: – Up to 5 MeV Alpha’s (helium nuclei) – Up to 3 MeV Beta particles (electrons) • Natural sources are difficult and limited: – Chemical processing: purity, messy, and expensive – Low intensity – Poor geometry – Uncontrolled energies, usually very broad Examples from the nature – electrostatic discharge, α- and β-decays, cosmic rays
“ Start the ball! olling. 1927: Lord rutherford requested a "copious supply"of projectiles more energetic than natural alpha and beta particles. At the opening of the resulting High Tension Laboratory, rutherford went on to reiterate the goal What we require is an apparatus to give us a potential of the order of 10 million volts which can be safely accommodated in a reasonably sized room and operated by a few kilowatts of power. We require too an exhausted tube capable of withstanding this voltage. I see no reason why such a requirement cannot be made practical
“Start the ball rolling…” 1927: Lord Rutherford requested a “copious supply” of projectiles more energetic than natural alpha and beta particles. At the opening of the resulting High Tension Laboratory, Rutherford went on to reiterate the goal: What we require is an apparatus to give us a potential of the order of 10 million volts which can be safely accommodated in a reasonably sized room and operated by a few kilowatts of power. We require too an exhausted tube capable of withstanding this voltage… I see no reason why such a requirement cannot be made practical
Why study. The construction, design and operation of particle accelerators uses knowledge from different branches of physics electromagnetism, high frequency electronics solid states physics, optics, vacuum technology, cryogenIcs, Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon
5 Why study... • The construction, design and operation of particle accelerators uses knowledge from different branches of physics: electromagnetism, high frequency electronics, solid states physics, optics, vacuum technology, cryogenics, ... • Learning about particle accelerator is a good opportunity to learn about many different physical phenomenon
Why They have wide ranging applications well beyond physics: health, life science, materials and even archaeology
Why ⚫They have wide ranging applications well beyond physics: health, life science, materials and even archaeology!
Early accelerators 1870: Discovery of the cathode rays by william Crookes Charged rays Propagation from the cathode to the anode A Crookes tube in which the cathode rays are deflected by a magnetic field Images source: Wikipedia 1896: J.J. Thomson shows that the cathode rays are made of particles"and measure the charge/mass ratio These particles are called electrons
7 Early accelerators 1870: Discovery of the cathode rays by William Crookes - Charged rays - Propagation from the Cathode to the anode A Crookes tube in which the Cathode rays are deflected by a magnetic field. 1896: J.J. Thomson shows that the cathode rays are made of “particles” and measure the charge/mass ratio. These particles are called “electrons” Images source: Wikipedia
Bremsstrahlung a charged particle emits radiation when it is accelerated An electron that Coulomb scatters on a heavy nucleus will change direction = acceleration Bremsstrahlung, braking radiation, is the name of the radiation emitted when a charged particle scatters on a heavy nucleus When a charged beam hits an object X-rays are emitted this is used to produce X- Incident rays in hospitals but it is also a source of Electrons hazardous radiations in accelerators Bremsstrahlung Bremsstrahlung is similar to synchrotron Elastically radiation Scattered Electron de/ds)rad EZ m Inelasticall Scattered Electron de/ ds)coll 700(M Image source http:/ww.ndt-ed.org/educationresourcEs/
8 Bremsstrahlung • When a charged beam hits an object, X-rays are emitted. This is used to produce Xrays in hospitals but it is also a source of hazardous radiations in accelerators. • Bremsstrahlung is similar to synchrotron radiation. ⚫ A charged particle emits radiation when it is accelerated. ⚫ An electron that Coulomb scatters on a heavy nucleus will change direction => acceleration ⚫ Bremsstrahlung, braking radiation, is the name of the radiation emitted when a charged particle scatters on a heavy nucleus. Image source: http://www.ndt-ed.org/EducationResources/
Improved resolution In quantum mechanics the wavelength of an object is related to its energy by A-h The reach better resolutions, the energy of the probe must be increased The energy of the electrons in Cathodic ray tubes is limited by the electrostatic generators available In the 1930s several generators where invented to produce high electric fields
9 Improved resolution • In quantum mechanics the wavelength of an object is related to its energy by ⚫ The reach better resolutions, the energy of the probe must be increased. ⚫ The energy of the electrons in Cathodic ray tubes is limited by the electrostatic generators available. ⚫ In the 1930s several generators where invented to produce high electric fields
vacuum on acceleration steering analyzer source
Ion source acceleration steering analyzer vacuum
