Abstract: There is provided a charged particle apparatus comprising: a particle beam generator, optics, a first and a second positioning device, both configured for positioning the substrate relative to the particle beam generator along its optical axis, and a controller configured for switching between a first operational mode and a second operational mode. The apparatus is configured, when operating in the first operational mode, for irradiating the substrate by the particle beam at a first landing energy of the particle beam and, when operating in the second operational mode, for irradiating the substrate at a second, different landing energy. When operating in the first operational mode, the second positioning device is configured to position the substrate relative to the particle beam generator at a first focus position of the particle beam and in the second operational mode, to position the substrate at a second, different focus position.

Abstract: A vacuum system configured to mitigate damage or risk associated with a pump malfunction (e.g., an imbalance, a catastrophic failure, etc.). An exemplary vacuum pump includes a housing; a vibration isolator coupled to the vacuum pump housing and configured to isolate vibrations generated by the vacuum pump during operation; and a stop structure disposed between the vacuum pump housing and an adjacent fixture. The stop structure configured to prevent displacement of the vacuum pump housing relative to the fixture above a threshold amount, wherein the displacement of the vacuum pump housing is configured to be within the threshold amount during normal operation. The vacuum system may further include a collar configured to limit an axial displacement of the pump.