Patent ID: 8274045

Claim:
A method, comprising: setting (S 101 ) a start time; extracting a first ion and a second ion (S 102 ) from different locations on a sample by an ionization pulse at a fixed time relative to the start time; accelerating (S 103 ) said first and second ions towards a signal generator (MCP) located at a distance to the sample whereby the distribution of the first and second ions on the sample is isomorphously imaged to the signal generator (MCP), wherein the signal generator comprises a microchannel plate; generating (S 103 ), by the signal generator (MCP), a first signal from the first ion and a second signal from the second ion, wherein the first signal and the second signal have an amplification factor between 10 3 and 10 7 and are indicative of a position of an impingement of the first and second ions onto the signal generator, respectively; detecting (S 104 ), by a first detection element of a detector, if a part of said first signal with at least a first pre-defined intensity is received by said first detection element and, by a second detection element of the detector, if a part of said second signal with at least a second pre-defined intensity is received by said second detection element, wherein the first and the second detection elements are laterally separated pixels on the detector which is a semiconductor detector; wherein the space, where the first and second ions travel towards the signal generator, the signal generator, and the detector are included in a vacuum chamber; wherein measuring (S 104 ) and storing (S 105 ), by the first detection element of the detector, a first time of arrival relative to the start time when said part of said first signal with at least the first pre-defined intensity is received by said first detection element, and measuring (S 104 ) and storing (S 105 ), by the second detection element of the detector, a second time of arrival relative to the start time when said part of said second signal with at least the second pre-defined intensity is received by said second detection element.