March 29, 2023
BETA BEAMS uses the MCNP software to design the electron beam shielding of equipment
In order to design electron beam equipment, BETA BEAMS uses different simulation tools.
One of these is MCNP (Monte Carlo N-Particle), a particle transport simulation software package developed by Los-Alamos National Laboratory, which allows detailed modeling of the interaction of particles with matter.
MCNP is capable of simulating many different types of particles, including photons, neutrons, electrons, protons and ions. The software can also take into account the complex geometry of the environment in which the particles move, as well as the properties of the materials through which they pass.
BETA BEAMS, uses this code to calculate the propagation of electrons in the material to obtain the optimal energy to pass through a given product. A dose can be obtained for different energies or thicknesses and thus facilitate the choice of the machine to be used for a particular case.
For example, in figure 1, a simple calculation case is presented where a mono-energetic electron beam passes through a 50µm thick titanium window, then a 500µm thick PET product. The calculated energies range from 300 to 500KeV. The curves show the dose variations at these energies as a function of the thickness passed through.
In this simple case we can see that a beam of 450KeV or 500KeV is necessary to completely cross the PET.
MCNP also allows the modeling of radiation protection shielding around the machines, to determine their thickness and their design. In this case, the calculated particles will be X-ray photons. The X-ray source is calculated with MCNP by sending an electron beam to a metal, to obtain the spectrum, but also the preferred direction of the X-ray source.