Editing Atom probe (section)

== Systems ==
Many designs have been constructed since the method's inception. Initial field ion microscopes, precursors to modern atom probes, were usually glass blown devices developed by individual research laboratories.

=== System layout ===
At a minimum, an atom probe will consist of several key pieces of equipment.
* A vacuum system for maintaining the low pressures (~10<sup>−8</sup> to 10<sup>−10</sup>&nbsp;Pa) required, typically a classic 3 chambered UHV design.
* A system for the manipulation of samples inside the vacuum, including sample viewing systems. 
* A cooling system to reduce atomic motion, such as a helium refrigeration circuit - providing sample temperatures as low as 15K.
* A high voltage system to raise the sample standing voltage near the threshold for field evaporation.
* A high voltage pulsing system, use to create timed field evaporation events
* A counter electrode that can be a simple disk shape (like earlier generation atom probes), or a cone-shaped Local Electrode. The voltage pulse (negative) is typically applied to the counter electrode. 
* A detection system for single energetic ions that includes XY position and TOF information.

Optionally, an atom probe may also include laser-optical systems for laser beam targeting and pulsing, if using laser-evaporation methods. In-situ reaction systems, heaters, or plasma treatment may also be employed for some studies as well as a pure noble gas introduction for FIM.

=== Performance ===
Collectable ion volumes were previously limited to several thousand, or tens of thousands of ionic events. Subsequent electronics and instrumentation development has increased the rate of data accumulation, with datasets of hundreds of million atoms (dataset volumes of 10<sup>7</sup>&nbsp;nm<sup>3</sup>). Data collection times vary considerably depending upon the experimental conditions and the number of ions collected. Experiments take from a few minutes, to many hours to complete.