2
E. Wilson and B. J. Holzer
where h represents Planck’s constant and p the particles’ momentum which relates
to its energy via the well-known equation of special relativity, E 2 = p 2 c 2 + m 2 c 4 .
The limit to the scale of detail that experiments can reveal is set by the length of
the wave which is scattered: rather as the wave breaking in the beach can only be
deflected by islands larger than itself. It was argued correctly that higher energy
particle, having the property of shorter wavelengths could better reveal the structure
of the nuclei that Rutherford has detected.
Such arguments led to the invention of the first accelerators and have sustained
the development of particle accelerators of higher and higher energy over the best
part of the last 100 years. At first, physicists used accelerators to probe the structure
of the nucleus, but went on to use higher energy accelerators to search for structure
in the “fundamental” particles—protons, neutrons and electrons they discovered.
Inevitably higher energies implied larger accelerators, for it was quickly discovered
that the best way to accelerate repetitively was to keep particle in a circular path
whose radius was itself proportional to energy, limited by the strength of the
magnetic field one might use to do the bending.
As energies were raised physicists found new and interesting particles to fit into
the pattern of those that their theories might predict. Einstein’s
E = mc
2
tells us that only high energies will create the more massive particles. The latest and
largest accelerator, LHC, flagship of the whole community, was designed to search
for the Higgs Boson and the successful discovery of this missing puzzle piece in
2013 allowed us to complete the Standard Model of Particle Physics.
As we write, this machine is carrying on the search for physics beyond the
standard model, seeking to disclose the nature of dark matter and dark energy.
As more powerful accelerators have been developed for high energy particle
physics, advances in the field have been exploited in a whole range of smaller
accelerators for other applications. From the time of the first cyclotrons they have
been used for producing isotopes and for treating cancer. The development of
compact high-frequency linac structures triggered the manufacture of hundreds of
small electron linacs producing X-rays for cancer treatment in hospitals around
the developed and, latterly, the developing world. Electron rings of a few GeV,
specially designed to produce beams of synchrotron radiation have become popular.
Each facility serves scores of experiments to investigate the structure of complex
molecules—particularly the proteins of today’s biomedical studies. Proton accelerators of about 1 GeV produce pulsed beams of neutrons by spallation which are
used principally to study the structure of materials. In addition thousands of lower
energy accelerators are used in industry for sterilisation and ion implantation in the
fabrication of sophisticated CPU chips for computers.
E. Wilson and B. J. Holzer
where h represents Planck’s constant and p the particles’ momentum which relates
to its energy via the well-known equation of special relativity, E 2 = p 2 c 2 + m 2 c 4 .
The limit to the scale of detail that experiments can reveal is set by the length of
the wave which is scattered: rather as the wave breaking in the beach can only be
deflected by islands larger than itself. It was argued correctly that higher energy
particle, having the property of shorter wavelengths could better reveal the structure
of the nuclei that Rutherford has detected.
Such arguments led to the invention of the first accelerators and have sustained
the development of particle accelerators of higher and higher energy over the best
part of the last 100 years. At first, physicists used accelerators to probe the structure
of the nucleus, but went on to use higher energy accelerators to search for structure
in the “fundamental” particles—protons, neutrons and electrons they discovered.
Inevitably higher energies implied larger accelerators, for it was quickly discovered
that the best way to accelerate repetitively was to keep particle in a circular path
whose radius was itself proportional to energy, limited by the strength of the
magnetic field one might use to do the bending.
As energies were raised physicists found new and interesting particles to fit into
the pattern of those that their theories might predict. Einstein’s
E = mc
2
tells us that only high energies will create the more massive particles. The latest and
largest accelerator, LHC, flagship of the whole community, was designed to search
for the Higgs Boson and the successful discovery of this missing puzzle piece in
2013 allowed us to complete the Standard Model of Particle Physics.
As we write, this machine is carrying on the search for physics beyond the
standard model, seeking to disclose the nature of dark matter and dark energy.
As more powerful accelerators have been developed for high energy particle
physics, advances in the field have been exploited in a whole range of smaller
accelerators for other applications. From the time of the first cyclotrons they have
been used for producing isotopes and for treating cancer. The development of
compact high-frequency linac structures triggered the manufacture of hundreds of
small electron linacs producing X-rays for cancer treatment in hospitals around
the developed and, latterly, the developing world. Electron rings of a few GeV,
specially designed to produce beams of synchrotron radiation have become popular.
Each facility serves scores of experiments to investigate the structure of complex
molecules—particularly the proteins of today’s biomedical studies. Proton accelerators of about 1 GeV produce pulsed beams of neutrons by spallation which are
used principally to study the structure of materials. In addition thousands of lower
energy accelerators are used in industry for sterilisation and ion implantation in the
fabrication of sophisticated CPU chips for computers.