# US 9,984,852 B1 · Time-of-flight charged particle spectroscopy > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,984,852 B1 - Document ID: US9984852B1 - Status: Granted - Kind: B1 - Application number: 15/364,145 - Filed: 2016-11-29 - Published: 2018-05-31 - Granted: 2018-05-29 - Earliest claimed: 2016-11-28 - Assignees: FEI Company - Applicants: FEI Company - Inventors: Otger Jan Luiten; Petrus Henricus Antonius Mutsaers; Jasper Frans Mathijs van Rens; Wouter Verhoeven; Erik René Kieft - Web page: https://patentgrep.com/patent/US9984852B1 ## CPC - H01J 37/26: Electron or ion microscopes; Electron or ion diffraction tubes - H01J 37/05: Electron or ion-optical arrangements for separating electrons or ions according to their energy {or mass}(particle separator tubes H01J49/00) - H01J 37/20: Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support - H01J 37/244: Detectors; Associated components or circuits therefor - H01J 2237/0437: Semiconductor substrate - H01J 2237/2442: Energy-dispersive (Si-Li type) spectrometer - H01J 2237/24485: Energy spectrometers - H01J 2237/2449: Detector devices with moving charges in electric or magnetic fields - H01J 2237/2626: Pulsed source - H01J 2237/2802: Transmission microscopes - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract An apparatus for performing charged particle spectroscopy, comprising: A source, for producing a pulsed beam of charged particles that propagate along a beam path; A specimen holder, for holding a specimen at an irradiation position in said beam path; A detector arrangement, for performing energy-differentiated detection of charged particles that traverse said specimen, wherein, between said source and said detector arrangement, said beam path successively traverses: An energizing cavity, for applying a time-dependent accelerating field to said beam; A primary drift space; Said irradiation position; A temporal focusing cavity, for converting an energy differential in said beam into a time-of-flight differential; A secondary drift space. ## Claims ### Claim 1 An apparatus for performing charged particle spectroscopy, comprising: a source, for producing a pulsed beam of charged particles that propagate along a beam path; a specimen holder, for holding a specimen at an irradiation position in said beam path; and a detector arrangement, for performing energy-differentiated detection of charged particles that traverse said specimen, wherein between said source and said detector arrangement, said beam path successively traverses: an energizing cavity, for applying a time-dependent accelerating field to said beam; a primary drift space; said irradiation position; a temporal focusing cavity, for converting an energy differential in said beam into a time-of-flight differential; and a secondary drift space. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein at least one of said energizing cavity and said temporal focusing cavity comprises a TM010 cavity. ### Claim 3 (depends on 1) An apparatus according to claim 1, wherein said detector arrangement comprises a TM110 cavity. ### Claim 4 (depends on 1) An apparatus according to claim 1, wherein said source comprises a TM110 cavity. ### Claim 5 (depends on 1) An apparatus according to claim 1, wherein a supplementary TM010 cavity is provided directly upstream or downstream of the temporal focusing cavity, and is configured to produce a second harmonic and reversed phase of the excitation in said temporal focus cavity. ### Claim 6 (depends on 1) An apparatus according to claim 1, wherein said apparatus is comprised in a charged particle microscope. ### Claim 7 (depends on 6) An apparatus according to claim 6, which is an EELS module. ### Claim 8 A method of performing charged particle spectroscopy, comprising: using a source to produce a pulsed beam of charged particles that propagate along a beam path; holding a specimen at an irradiation position in said beam path; using a detector arrangement to perform energy-differentiated detection of charged particles that traverse said specimen, upstream of said irradiation position, using an energizing cavity to apply a time-dependent accelerating field to said beam, and then passing the beam through a primary drift space; and downstream of said irradiation position and upstream of said detector arrangement, using a temporal focusing cavity to convert an energy differential in said beam into a time-of-flight differential, and then passing the beam through a secondary drift space. ### Claim 9 (depends on 8) A method according to claim 8, wherein: specimen has a property that changes as a function of time; and pulsed beam is used to assemble a temporal series of momentary spectroscopic snapshots of said specimen, thereby capturing temporal evolution of said property. ### Claim 10 (depends on 2) An apparatus according to claim 2, wherein said detector arrangement comprises a TM110 cavity. ### Claim 11 (depends on 2) An apparatus according to claim 2, wherein said source comprises a TM110 cavity. ### Claim 12 (depends on 3) An apparatus according to claim 3, wherein said source comprises a TM110 cavity. ### Claim 13 (depends on 2) An apparatus according to claim 2, wherein a supplementary TM010 cavity is provided directly upstream or downstream of the temporal focusing cavity, and is configured to produce a second harmonic and reversed phase of the excitation in said temporal focus cavity. ### Claim 14 (depends on 3) An apparatus according to claim 3, wherein a supplementary TM010 cavity is provided directly upstream or downstream of the temporal focusing cavity, and is configured to produce a second harmonic and reversed phase of the excitation in said temporal focus cavity. ### Claim 15 (depends on 4) An apparatus according to claim 4, wherein a supplementary TM010 cavity is provided directly upstream or downstream of the temporal focusing cavity, and is configured to produce a second harmonic and reversed phase of the excitation in said temporal focus cavity. ### Claim 16 (depends on 2) An apparatus according to claim 2, wherein said apparatus is comprised in a charged particle microscope. ### Claim 17 (depends on 3) An apparatus according to claim 3, wherein said apparatus is comprised in a charged particle microscope. ### Claim 18 (depends on 4) An apparatus according to claim 4, wherein said apparatus is comprised in a charged particle microscope. ### Claim 19 (depends on 5) An apparatus according to claim 5, wherein said apparatus is comprised in a charged particle microscope. ### Claim 20 (depends on 16) An apparatus according to claim 16, which is an EELS module.