Passive scattering (do you mean bremsstrahlung target?) increases beam divergence in both transverse dimensions. Collimators are then used to limit and shape the beam (protons) or bremsstrahlung (electrons) divergence.lavster said:does that mean that broom beams are the type of beam that is produced by passive scattering? and it needs things such as a dynamic multileaf collimeter to focus it onto the tumour in cancer therapy?
Let me ask you this question: If you use an F-stop of 1.4 on a camera lens, how do you prevent the depth of field from getting paper thin? Electron beams are never used directly on patients. Only collimated X-rays or bremsstrahlung from electron beams are used on patients. See Fig, 4.8 on page 42 inhowever, what does thin wide beam mean - i took from what you said that it starts off thin then gets wider? but isn't that undesirable and the opposite of being focused? so why would you use it? Finally, why do you split the two types of beams into charged particle beams and electron beams...an electron is a charged particle?
Collimators cannot focus anything. Collimators only block divergent radiation outside the tumour area. Only magnets can focus only charged particle beams. A dynamic collimator is made of leaves of tungsten, and the shape is dynamically changing as the accelerator pivots around the patient. On an electron machine (e.g., Varian), the patient can see the tungsten leaves inside the end window of the accelerator.lavster said:...and it needs things such as a dynamic multileaf collimeter to focus it onto the tumour in cancer therapy?
A pencil beam is a narrow, focused beam of light or particles, while a broom beam is a wider, more diffuse beam. Pencil beams are used for precision targeting and imaging, while broom beams are used for larger coverage areas.
Pencil beams are often created using lenses or collimators to narrow the beam, while broom beams can be created through diffraction or scattering processes.
Pencil beams are commonly used in medical imaging, microscopy, and laser cutting, while broom beams are used in astronomy, remote sensing, and particle accelerators.
Yes, both pencil and broom beams can be manipulated using optical elements such as lenses, mirrors, and filters to change their direction, focus, or polarization.
The main advantage of pencil beams is their precision and ability to target specific areas, while the advantage of broom beams is their wider coverage area. However, pencil beams can be limited in their depth of penetration, while broom beams may have lower resolution and require more power. Both beam types have their own unique advantages and disadvantages depending on the application.