Ultrafast electron microscopy: Instrument response from the single-electron to high bunch-charge regimes

Plemmons, Dayne A.; Flannigan, David J.

doi:10.1016/j.cplett.2017.01.055

Cited by 59 publications

(50 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…10 Though the factors and the mechanisms associated with beam damage are numerous and multi-faceted, a number of practical approaches have been shown to significantly reduce negative effects of radiolysis, the damage mechanism most relevant to radiation-sensitive organic matter (2). For example, cryogenic methods operate by holding the specimen at reduced temperatures during exposure in order to lower diffusion and kinetic reaction rates, to reduce 15 mass loss, and to minimize the impact of beam-induced thermal effects, especially for poorlyconducting materials (3,4). This has led to significant advances in the ability to study highlysensitive specimens, such as soft matter and biological structures, at sub-nanometer spatial scales (5)(6)(7)(8).…”

mentioning

confidence: 99%

Reducing Radiation Damage in Soft Matter with Femtosecond Timed Single-Electron Packets

VandenBussche¹,

Flannigan

2019

Preprint

View full text Add to dashboard Cite

Despite development of myriad mitigation methods, radiation damage continues to be a major limiting factor in transmission electron microscopy. Intriguing results have been reported using pulsed-laser driven and chopped electron beams for modulated dose delivery, but 10 the underlying relationships and effects remain unclear. Indeed, delivering precisely-timed single-electron packets to the specimen has yet to be systematically explored, and no direct comparisons to conventional methods within a common parameter space have been made. Here, using a model linear saturated hydrocarbon (n-hexatriacontane, C 36 H 74 ), we show that preciselytimed delivery of each electron to the specimen, with a well-defined and uniform time between 15 arrival, leads to a repeatable reduction in damage compared to conventional ultralow-dose methods for the same dose rate and the same accumulated dose. Using a femtosecond pulsed laser to confine the probability of electron emission to a 300-fs temporal window, we find damage to be sensitively dependent on the time between electron arrival (controlled with the laser repetition rate) and on the number of electrons per packet (controlled with the laser-pulse 20 energy). Relative arrival times of 5, 20, and 100 µs were tested for electron packets comprised of, on average, 1, 5, and 20 electrons. In general, damage increased with decreasing time between electrons and, more substantially, with increasing electron number. Further, we find that improvements relative to conventional methods vanish once a threshold number of electrons per packet is reached. The results indicate that precise electron-by-electron dose delivery leads 25 to a repeatable reduction in irreversible structural damage, and the systematic studies indicate this arises from control of the time between sequential electrons arriving within the same damage radius, all else being equal.

show abstract

mentioning

confidence: 99%

Reducing Radiation Damage in Soft Matter with Femtosecond Timed Single-Electron Packets

VandenBussche¹,

Flannigan

2019

Preprint

View full text Add to dashboard Cite

show abstract

“…6 presents the 3D evolution of our non-diffracting wavefunction, while the right column shows the 3D evolution of a Bessel beam. The simulations parameters are acceleration voltage of 20 kV, 100 electrons in a pulse of duration of ~200 fs ( L = 100 fs), which is just about the shortest ultrashort pulses in electron microscopy 52 – 54 . Technically, launching such a non-diffracting ultrashort electron pulse would require incorporating the holographic scheme of Fig.…”

Section: Resultsmentioning

confidence: 99%

Non-diffracting multi-electron vortex beams balancing their electron–electron interactions

et al. 2017

View full text Add to dashboard Cite

The wave-like nature of electrons has been known for almost a century, but only in recent years has the ability to shape the wavefunction of EBeams (Electron-Beams) become experimentally accessible. Various EBeam wavefunctions have been demonstrated, such as vortex, self-accelerating, Bessel EBeams etc. However, none has attempted to manipulate multi-electron beams, because the repulsion between electrons rapidly alters the beam shape. Here, we show how interference effects of the quantum wavefunction describing multiple electrons can be used to exactly balance both the repulsion and diffraction-broadening. We propose non-diffracting wavepackets of multiple electrons, which can also carry orbital angular momentum. Such wavefunction shaping facilitates the use of multi-electron beams in electron microscopy with higher current without compromising on spatial resolution. Simulating the quantum evolution in three-dimensions and time, we show that imprinting such wavefunctions on electron pulses leads to shape-preserving multi-electrons ultrashort pulses. Our scheme applies to any beams of charged particles, such as protons and ion beams.

show abstract

“…Additionally, rigorous comparison of pulsed and continuous beam on one microscope has been challenging on the picosecond scale because the laser-driven cathode modifications replace the normal thermionic or Schottky field emission cathode used for (continuous) operation of the TEM 18 . The size, divergence, and energy spread of the modified cathode's pulsed (photoemitted) beam differ from continuous (thermionic or Schottky) emission, a fundamental challenge when comparing pulsed and continuous beam in laser-based pulsed TEM systems.…”

Section: Introductionmentioning

confidence: 99%

Mitigation of radiation damage in biological macromolecules via tunable picosecond pulsed transmission electron microscopy

Choe

Пономарев

Montgomery

et al. 2020

Preprint

View full text Add to dashboard Cite

We report mitigation of electron-beam-induced radiation damage in biological macromolecules using rapid, low-dose transmission electron microscopy (TEM) with a new, tunable, retrofittable stroboscopic pulser. Damage mitigation strategies historically consisted of sample cryoprotection and ultra-low beam current; ultrafast laser-pulsed systems have shown promise, but with day-long acquisition times. We show the first practical, fast, laser-free tunable system, with acquisition of diffraction series in minutes at 5.2 GHz and 10 pA. This is the largest study to date: two materials (C 36 H 74 paraffin and purple membrane), two beam energies (200 keV and 300 keV), two independent microscopes (Schottky and LaB 6 ), two modes (pulsed and continuous), and unsurpassed repetition rate tunability. Critical dose at room temperature doubled versus continuous beam for~100 MHz single-electron repetition rates. Results herald a new class of highly-tunable, ultrafast pulsers with future applications in cryogenic electron microscopy (CryoEM), high resolution single particle imaging, and rapid low-dose TEM.

show abstract

Ultrafast electron microscopy: Instrument response from the single-electron to high bunch-charge regimes

Cited by 59 publications

References 45 publications

Reducing Radiation Damage in Soft Matter with Femtosecond Timed Single-Electron Packets

Reducing Radiation Damage in Soft Matter with Femtosecond Timed Single-Electron Packets

Non-diffracting multi-electron vortex beams balancing their electron–electron interactions

Mitigation of radiation damage in biological macromolecules via tunable picosecond pulsed transmission electron microscopy

Contact Info

Product

Resources

About

Ultrafast electron microscopy: Instrument response from the single-electron to high bunch-charge regimes

Cited by 59 publications

References 45 publications

Reducing Radiation Damage in Soft Matter with Femtosecond Timed Single-Electron Packets

Reducing Radiation Damage in Soft Matter with Femtosecond Timed Single-Electron Packets

Non-diffracting multi-﻿electron vortex beams balancing their electron–electron interactions

Mitigation of radiation damage in biological macromolecules via tunable picosecond pulsed transmission electron microscopy

Contact Info

Product

Resources

About

Non-diffracting multi-electron vortex beams balancing their electron–electron interactions