Track Models

The chapter shows how the equations of motion for charged particles in a homogeneous or inhomogeneous magnetic field are solved. Various types of parametrizations are presented, and formulas for track propagation and error propagation are derived. As the effects of the detector material on the trajectory have to be taken into account, the statistical properties of multiple Coulomb scattering, energy loss by ionization, and energy loss by bremsstrahlung are discussed; then it is shown how the effects can be treated in the track reconstruction. As multiple scattering in thin layers and energy loss by bremsstrahlung have distinctive non-Gaussian features, an approximation by normal mixtures is presented.

Interactions of particles with matter

Particles are sensed through their interactions with matter. To begin with, the chapter introduces the terms cross section and absorption. Then successively the most important interactions that are employed for the detection of the various particle types are discussed: energy loss of charged particles by ionisation and bremsstrahlung, multiple Coulomb scattering of charged particles, interactions of photons and hadrons with matter. The interactions leading to the development of electromagnetic and hadronic showers are treated in more detail in chapter 15 (Calorimeters), while energy loss by Cherenkov and transition radiation are discussed in chapters 11 and 12, respectively. When describing the interaction processes an attempt is made to address the theoretical background in a way that the derivations ought to be comprehensible.

Novel laser-plasma TeV electron-positron linear colliders

TeV center-of-mass energy electron-positron linear colliders comprising seamlessly staged capillary laser-plasma accelerators are presented. A moderate intensity laser pulse coupled with the single electromagnetic hybrid mode in a gas-filled capillary can generate plasma waves in the linear regime, where laser wakefields can accelerate equally focused electron and positron beams. In multiple stage capillary accelerators, a particle beam with respect to the laser wakefield can undergo consecutive acceleration up to TeV energies, associated with continuous transverse focusing in a beam size down to a nanometer level, being capable of a promising electron-positron linear collider with very high luminosities of the order of 10[Formula: see text] cm[Formula: see text]s[Formula: see text]. The transverse and longitudinal beam dynamics of beam particles in plasma wakefields with the effects of radiation reaction and multiple Coulomb scattering are investigated numerically to estimate the luminosities in beam-beam collisions with the effects of beamstrahlung radiation and bunch disruption.

Proton Radiography by Multiple Coulomb Scattering with Nuclear Emulsion Detectors

The possibility of performing proton radiography by using the proton angular spread due to Coulomb multiple scattering was investigated, for the first time, with an emulsion film detector. Two different phantoms were irradiated with the therapeutic proton beam at the Paul Scherrer Institut (PSI) in Villigen, Switzerland. The first one is a simple polymethylmethacrylate (PMMA) block having two different thicknesses (4 cm and 3 cm), and the second one is a PMMA cube with five aluminum rods embedded along a diagonal. Only one emulsion film was needed to perform the radiography, an important issue as the analysis of this kind of detector is time-consuming. Furthermore, the method showed an enhanced contrast when high atomic-number materials are traversed. This gives an advantage, when compared to proton range radiography.

Механизмы отражения и преломления пучка заряженных частиц в рассеивающей среде

The mathematical model describing the reflection and refracting phenomena at incline border of scattering medium and vacuum for a moving charged particle traversing this border is suggested. To build such a model, the distribution function for multiple Coulomb scattering processes in unbounded medium is used. Formulae for refraction angle and reflection coefficient are derived followed by numerical calculations and appropriate plots.