1
|
Cheng C, Frasinski LJ, Moğol G, Allum F, Howard AJ, Rolles D, Bucksbaum PH, Brouard M, Forbes R, Weinacht T. Multiparticle Cumulant Mapping for Coulomb Explosion Imaging. Phys Rev Lett 2023; 130:093001. [PMID: 36930921 DOI: 10.1103/physrevlett.130.093001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
We extend covariance velocity map ion imaging to four particles, establishing cumulant mapping and allowing for measurements that provide insights usually associated with coincidence detection, but at much higher count rates. Without correction, a fourfold covariance analysis is contaminated by the pairwise correlations of uncorrelated events, but we have addressed this with the calculation of a full cumulant, which subtracts pairwise correlations. We demonstrate the approach on the four-body breakup of formaldehyde following strong field multiple ionization in few-cycle laser pulses. We compare Coulomb explosion imaging for two different pulse durations (30 and 6 fs), highlighting the dynamics that can take place on ultrafast timescales. These results have important implications for Coulomb explosion imaging as a tool for studying ultrafast structural changes in molecules, a capability that is especially desirable for high-count-rate x-ray free-electron laser experiments.
Collapse
Affiliation(s)
- Chuan Cheng
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Leszek J Frasinski
- Department of Physics, Imperial College London, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - Gönenç Moğol
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Andrew J Howard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Daniel Rolles
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Philip H Bucksbaum
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Ruaridh Forbes
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Thomas Weinacht
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| |
Collapse
|
2
|
Cheng C, Moğol G, Weinacht T, Nomerotski A, Trallero-Herrero C. 3D velocity map imaging of electrons with TPX3CAM. Rev Sci Instrum 2022; 93:013003. [PMID: 35104954 DOI: 10.1063/5.0071804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
We demonstrate three-dimensional velocity map imaging of low energy electrons using a TPX3CAM, where the three-dimensional momentum information [px, py, pz] is encoded in position and timing [x, y, t] of hits on the camera sensor. We make use of the camera sensor for the [x, y] information and a constant fraction discriminator and fast time to digital converter in the camera for the time information. We illustrate the capabilities of our apparatus by presenting above threshold ionization measurements of xenon, which produces well defined structures in the momentum resolved photoelectron yield.
Collapse
Affiliation(s)
- Chuan Cheng
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - Gönenç Moğol
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - Thomas Weinacht
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - Andrei Nomerotski
- Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | | |
Collapse
|