Spencer Gessner
Assistant Professor of Particle Physics and Astrophysics
Academic Appointments
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Assistant Professor, Particle Physics and Astrophysics
All Publications
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Correlations between X-rays, visible light and drive-beam energy loss observed in plasma wakefield acceleration experiments at FACET-II
JOURNAL OF PLASMA PHYSICS
2024; 90 (4)
View details for DOI 10.1017/S0022377824000734
View details for Web of Science ID 001314642300001
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Wakefield generation in hydrogen and lithium plasmas at FACET-II: Diagnostics and first beam-plasma interaction results
PHYSICAL REVIEW ACCELERATORS AND BEAMS
2024; 27 (5)
View details for DOI 10.1103/PhysRevAccelBeams.27.051302
View details for Web of Science ID 001241703400001
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Positron acceleration in plasma wakefields
PHYSICAL REVIEW ACCELERATORS AND BEAMS
2024; 27 (3)
View details for DOI 10.1103/PhysRevAccelBeams.27.034801
View details for Web of Science ID 001187481200001
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Temporal evolution of the light emitted by a thin, laser-ionized plasma source
PHYSICS OF PLASMAS
2024; 31 (1)
View details for DOI 10.1063/5.0180416
View details for Web of Science ID 001143690900001
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Status and future plans for C<SUP>3</SUP> R&D
JOURNAL OF INSTRUMENTATION
2023; 18 (9)
View details for DOI 10.1088/1748-0221/18/09/P09040
View details for Web of Science ID 001100999100010
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Beam delivery and beamstrahlung considerations for ultra-high energy linear colliders
JOURNAL OF INSTRUMENTATION
2023; 18 (9)
View details for DOI 10.1088/1748-0221/18/09/P09022
View details for Web of Science ID 001103957900003
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A liquid xenon positron target concept
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
2023; 1053
View details for DOI 10.1016/j.nima.2023.168329
View details for Web of Science ID 001113617800001
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Probing strong-field QED in beam-plasma collisions (vol 6, 141, 2023)
COMMUNICATIONS PHYSICS
2023; 6 (1)
View details for DOI 10.1038/s42005-023-01294-x
View details for Web of Science ID 001026855700001
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Probing strong-field QED in beam-plasma collisions
COMMUNICATIONS PHYSICS
2023; 6 (1)
View details for DOI 10.1038/s42005-023-01263-4
View details for Web of Science ID 001008596100001
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9 GeV energy gain in a beam-driven plasma wakefield accelerator
PLASMA PHYSICS AND CONTROLLED FUSION
2016; 58 (3)
View details for DOI 10.1088/0741-3335/58/3/034017
View details for Web of Science ID 000371571600018
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Adaptive method for electron bunch profile prediction
PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS
2015; 18 (10)
View details for DOI 10.1103/PhysRevSTAB.18.102801
View details for Web of Science ID 000362913500001
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Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield
NATURE
2015; 524 (7566): 442-?
Abstract
Electrical breakdown sets a limit on the kinetic energy that particles in a conventional radio-frequency accelerator can reach. New accelerator concepts must be developed to achieve higher energies and to make future particle colliders more compact and affordable. The plasma wakefield accelerator (PWFA) embodies one such concept, in which the electric field of a plasma wake excited by a bunch of charged particles (such as electrons) is used to accelerate a trailing bunch of particles. To apply plasma acceleration to electron-positron colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas. Although substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch, such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFAs where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered--'self-loaded'--so that about a billion positrons gain five gigaelectronvolts of energy with a narrow energy spread over a distance of just 1.3 metres. They extract about 30 per cent of the wake's energy and form a spectrally distinct bunch with a root-mean-square energy spread as low as 1.8 per cent. This ability to transfer energy efficiently from the front to the rear within a single positron bunch makes the PWFA scheme very attractive as an energy booster to an electron-positron collider.
View details for DOI 10.1038/nature14890
View details for Web of Science ID 000360069300032
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High-efficiency acceleration of an electron beam in a plasma wakefield accelerator
NATURE
2014; 515 (7525): 92-?
View details for DOI 10.1038/nature13882
View details for Web of Science ID 000344187500035
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Laser ionized preformed plasma at FACET
PLASMA PHYSICS AND CONTROLLED FUSION
2014; 56 (8)
View details for DOI 10.1088/0741-3335/56/8/084011
View details for Web of Science ID 000340055300012
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Extremum Seeking for Parameter Identification, Implementation for Electron Beam Property Prediction
IEEE. 2014: 2673–78
View details for Web of Science ID 000370073802131