Apparatus with permanent magnetic lenses

A method of directing a charged particle beam toward a sample, comprising:

• generating a beam of charged particles from a charged particle source;
• directing the beam of charged particles through a first magnetic field of a first permanent magnet of a first lens systems and a second magnetic field of a second permanent magnetic of a second lens system wherein the first lens system and the second lens system do not include any magnetic coil;
• adjusting the beam properties by altering the voltage on an element within the first lens system, the voltage on an element within the second lens system, or the voltage on elements within both lens systems.

A method of directing a charged particle beam toward a sample, comprising:

• generating a beam of charged particles from a charged particle source;
• directing the beam of charged particles through a first magnetic field of a first permanent magnet of a first lens systems and a second magnetic field of a second permanent magnetic of a second lens system wherein the first lens system and the second lens system do not make use of any magnetic coil;
• adjusting the beam properties by altering the potential energy within the first lens system, the second lens system, or within both lens systems to vary the potential energy gradient from the uniform gradient produced by the potential applied between the charged particle beam source and the sample.