Modeling quadrupole mass analyzers with OmniTrak

Linear quadrupoles are widely used for ion mass spectrometry. They can separate ions by the ratio of mass number to charge number (M/Z) without a magnetic field, leading to compact, light and inexpensive systems. An assembly consists of a source of low-energy ions that enter an extended electrostatic¬† quadrupole. The voltage applied to the lens has […]

Building solids in MetaMesh

The programs Geometer and MetaMesh are used to build three-dimensional meshes for our multi-physics solution programs using constructive solid geometry. The user has the option to assemble objects from native models (e.g., spheres, cylinders, boxes, turnings,…) or to import complex shapes from SolidWorks and other 3D CAD programs. This article reviews how to make objects with […]

GamBet shielding calculation walkthrough

In a previous article, I discussed the basis of the H*(10) standard for radiation safety. Here, I’ll continue by demonstrating techniques for shielding calculations. I’ll use a published simple benchmark calculation to compare the results to several other Monte Carlo codes and to illustrate some of the advantages of GamBet. For this, I am grateful to […]

H*(10) calculations with GamBet

I recently had an inquiry from a prospective customer. He had investigated several Monte Carlo options and was impressed with one package because the developer emphasized that the software could perform H*(10) calculations. In reality, every Monte Carlo X-ray code has this capability. The only requirement is that the user be aware of the definition. To […]

Magnetic saturation: educated guessing

In finite-element solutions at low magnetic fields, the properties of ferromagnetic materials are not critically important. The quantity used in the solutions is ?= 1/?r. In this case, both 1/800 and 1/8000 are close to zero compared to unity; therefore, the details of the ?r(B) curve make little difference in the solution. On the other hand, […]