Accelerator Physics
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Y.
Ma
,
M. j. V.
Streeter
,
F.
Albert
,
N.
Bourgeois
,
S.
Cipiccia
,
J. M.
Cole
,
S. j. D.
Dann
,
K.
Falk
,
E.
Gerstmayr
,
I.
Gallardo González
,
A.
Higginbotham
,
A. E.
Hussein
,
D. A.
Jaroszynski
,
A. s.
Joglekar
,
B.
Kettle
,
K.
Krushelnick
,
N.
Lemos
,
N. C.
Lopes
,
C.
Lumsden
,
O.
Lundh
,
S. P. D.
Mangles
,
K. G.0000-0003-4826-9001
Miller
,
W.
Mori
,
Z.
Najmudin
,
Q.
Qian
,
P. P.
Rajeev
,
D.
Seipt
,
M.
Shahzad
,
M.
Šmíd
,
R.
Spesyvtsev
,
D. R.
Symes
,
G.
Vieux
,
L.
Willingale
,
J. C.
Wood
,
A. G. R.
Thomas
Open Access
Abstract: We report on a single-shot longitudinal phase-space reconstruction diagnostic for electron beams in a laser wakefield accelerator via the experimental observation of distinct periodic modulations in the angularly resolved spectra. Such modulated angular spectra arise as a result of the direct interaction between the ultrarelativistic electron beam and the laser driver in the presence of the wakefield. A constrained theoretical model for the coupled oscillator, assisted by a genetic algorithm, can recreate the experimental electron spectra and, thus, fully reconstructs the longitudinal phase-space distribution of the electron beam with a temporal resolution of approximately 1.3 fs. In particular, it reveals the slice energy spread of the electron beam, which is important to measure for applications such as x-ray free electron lasers. In our experiment, the root-mean-square slice energy spread retrieved is bounded at 9.9 MeV, corresponding to a 0.9%–3.0% relative spread, despite the overall GeV energy beam having approximately 100% relative energy spread.
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Sep 2025
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I13-1-Coherence
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Diamond Proposal Number(s):
[29218, 23409, 32637, 34164]
Abstract: In conventional x-ray ptychography, diffraction data are collected by scanning a sample through a monochromatic and spatially coherent x-ray beam. A high-resolution image is then retrieved using an iterative algorithm. Combined with a scan of the incident photon energy, it is also possible to access chemical and elemental information. Although powerful, the high brilliance required currently constrains the method to third and fourth generation synchrotron sources and long scanning times. An alternative approach is to use broadband illumination in combination with an energy resolving detector. These detectors record the data in a series of energy channels simultaneously, creating stacks of coherent data suitable for a ptychographic reconstruction. This approach promises to unlock the full power of the radiation source and provide spectral imaging at a higher rate and in a single acquisition. However, these detectors currently saturate well below reaching the flux rates produced at synchrotrons, which is preventing the uptake of this approach. Furthermore, current monochromatic synchrotron setups typically employ Fresnel zone plates for pre-sample focusing due to their stability, flexibility, and affordability, but these diffractive optics limit the spectral bandwidth that the setup can accept. In this article, we analyze the problem and consider alternative optics that can both maximize the total photon detection rates and broaden the tolerable bandwidth. Broadband x-ray ptychography has the potential to dramatically reduce data collection times at synchrotron sources but also to harness the full power of lower brilliance sources and transition x-ray ptychography into a laboratory technique.
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Aug 2025
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I13-1-Coherence
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Emily C.
Bamber
,
Fabio
Arzilli
,
Silvia
Cipiccia
,
Darren J.
Batey
,
Giuseppe
La Spina
,
Margherita
Polacci
,
Ali
Gholinia
,
Heath
Bagshaw
,
Danilo
Di Genova
,
Richard
Brooker
,
Daniele
Giordano
,
Pedro
Valdivia
,
Mike R.
Burton
Diamond Proposal Number(s):
[23863]
Open Access
Abstract: Nanoscale crystals are becoming increasingly recognised in the products of volcanic eruptions, spanning a range of magma compositions. The crystallisation of nanolites impacts magma rheology, ascent dynamics, and eruptive style. Their impact can be enhanced due to their capacity to aggregate and develop neighbouring chemically differentiated boundary layers. However, their 3D interaction, spatial distribution, and morphology is not currently understood. Here we present a cutting-edge, 3D nanometre-scale visualisation and quantification of nanolites in scoriae of the Las Sierras-Masaya basaltic Plinian eruptions, acquired using X-ray ptychography. We find that Ti-magnetite nanolites aggregate, forming elongate, irregular structures in 3D. Their crystallisation extracts Fe and Ti from the melt, resulting in differentiated boundary layers with higher viscosity. Syn-eruptive crystallisation of nanolites and their interaction is estimated to have increased magma viscosity by 2–3 orders of magnitude, therefore, they likely had a strong control on magma rheology, increasing the potential of magma fragmentation.
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Aug 2025
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I13-1-Coherence
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Diamond Proposal Number(s):
[34164]
Open Access
Abstract: X-ray ptychography is a robust microscopy technique with nanoscale resolution that requires a spatially and temporally coherent illumination. In a typical setup, the temporal coherence requirements are satisfied by monochromating the x-ray source, e.g., using a crystal monochromator. Recent studies have shown that energy resolving, or hyperspectral, detectors can to some extent replace the role of the monochromator to perform, e.g., edge-subtraction ptychographic imaging with broadband radiation in a single acquisition. Scaling this capability from two dimensions (2D) to three dimensions (3D), and from a single absorption edge to multiple edges, is critical for its applications in structural and elemental characterisation. The method is hitherto limited by the inherently lower maximum count rate of hyperspectral detectors and the chromaticity of the optics often used in x-ray ptychography experiments, namely Fresnel zone plates. In this work, we design an optimized broadband spectroscopic ptychography setup and use it to perform 3D hyperspectral imaging of particles of battery material containing various percentages of nickel, manganese, cobalt (NMC). We show that we can identify different compositions based on their spectral response. We discuss the results and provide guidelines for future exploitation of the method in laboratory settings.
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Jun 2025
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I13-1-Coherence
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Michela
Fratini
,
Lorenzo
Massimi
,
Francesco
Brun
,
Darren
Batey
,
Inna
Bukreeva
,
Alberto
Mittone
,
Alberto
Bravin
,
Elena
Longo
,
Giuliana
Tromba
,
Federico
Giove
,
Silvia
Cipiccia
,
Alejandra
Sierra
Diamond Proposal Number(s):
[32221]
Open Access
Abstract: The choice of fixative is critical in X-ray phase-contrast tomography (XPCT) because it affects tissue preservation, contrast enhancement and compatibility with other imaging techniques. A careful selection and optimization of fixatives can lead to significant improvements in the quality and accuracy of imaging results, which is especially important when studying complex biological systems such as those involved in neurodegeneration, where it is crucial to maintain the fine details of the Grey Matter (GM) and White Matter (WM) structures. Dehydration with ethanol and xylene is commonly used as it effectively removes water while minimising structural alterations. Using perfusion in ethanol and dehydration in xylene as a secondary fixative can increase the contrast, thereby improving the visibility of myelinated fibers without using a contrast agent. In this paper we discuss an optimised fixation method to significantly enhance the contrast and boost the signal to noise ratio (SNR) in XPCT images of WM in the central nervous system (CNS).
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Jun 2025
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I13-1-Coherence
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E.
Erin
,
L.
Fardin
,
D.
Batey
,
M.
Burian
,
S.
Vogel
,
S.
Grimm
,
M.
Fratini
,
M.
Palombo
,
F.
Zhou
,
G. J. M.
Parker
,
A.
Olivo
,
S.
Cipiccia
Diamond Proposal Number(s):
[34189, 32306]
Open Access
Abstract: X-ray ptychography is a scanning coherent diffraction imaging technique which combines nanometer-scale resolution with high penetration depth. This method has been proven to be suitable for scanning weakly absorbing samples and therefore potentially very valuable for medical applications such as brain imaging. However, currently employed scanning techniques present challenges: step-scanning is too slow and inefficient, while fly-scanning introduces blurring and noise into reconstructions due to the motion and reduced photon counts per pixel. To date, only a few methods have been proposed to denoise reconstructions, most of which rely on traditional approaches and are limited in addressing the challenges posed by noise and blurring. To overcome these limitations, we investigate the possibility of using a deep learning-based denoising method combined with position binning. The deep learning-based denoising method, Deep Image Prior (DIP), denoises the reconstructions while position binning increases the photon count statistics per pixel. The method can be integrated within the existing iterative phase retrieval algorithms to denoise the object or probe in between iterations. The method is tested in far-field geometry on two different samples: a Siemens star resolution target and a polymer-based phantom mimicking the white matter of the brain. By assessing the resolution via Fourier ring correlation, we measure up to a 14% increase in the resolution. However, depending on the architecture used, artifacts due to machine hallucination appear in the denoised images which could be affecting the observed enhancement in resolution. This will be the subject of further investigation.
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May 2025
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Luca
Fardin
,
Yelyzaveta
Pulnova
,
Tomáš
Parkman
,
Iuliia
Baranová
,
Sylvain
Fourmaux
,
Chris
Armstrong
,
Michela
Fratini
,
Uddhab
Chaulagain
,
Jaroslav
Nejdl
,
Borislav
Angelov
,
Darren J.
Batey
,
Alessandro
Olivo
,
Silvia
Cipiccia
Open Access
Abstract: Ptychography is a robust lensless form of microscopy routinely used for applications spanning life and physical sciences. The most common ptychography setup consists in using a detector to record diffraction patterns in the far-field. A near-field version has been more recently introduced, and its potential is yet to be fully exploited. In this work, the sampling requirements for near-field ptychography are analysed. Starting from the characterisation available in literature, the formalism of the fractional Fourier transform is used to generalise analytically the sampling conditions. The results harmonise the far- and near-field regimes and widen the applications of the technique with respect to the current knowledge. This study is supported by simulations and provides clear guidelines on how to optimise the setup and acquisition strategies for near-field ptychography experiments. The results are key to drive the translation of the technique towards low brilliance sources.
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Apr 2025
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I13-1-Coherence
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Emily C.
Bamber
,
Fabio
Arzilli
,
Giuseppe
La Spina
,
Margherita
Polacci
,
Silvia
Cipiccia
,
Darren J.
Batey
,
Lucia
Mancini
,
Mattia
De' Michieli Vitturi
,
Ali
Gholinia
,
Heath
Bagshaw
,
Danilo
Di Genova
,
Richard
Brooker
,
Daniele
Andronico
,
Rosa Anna
Corsaro
,
Daniele
Giordano
,
Pedro
Valdivia
,
Mike R.
Burton
Open Access
Abstract: The explosivity of a volcanic eruption is controlled by several interdependent processes during magma ascent, such as crystallisation, gas exsolution and outgassing. Syn-eruptive crystallisation can increase the potential of magma fragmentation. Whilst the degree of coupling between the gas and melt phases during ascent can influence eruptive style. Quantitative textural analysis of vesicles and crystals in erupted products can provide insight into syn-eruptive conduit processes and the conditions leading to magma fragmentation. Synchrotron-based imaging techniques such as X-ray computed micro-tomography can provide information on vesicle and crystal size, shape and their spatial distribution in 3D. Furthermore, X-ray ptychography, an X-ray microscopy technique with nanoscale resolution, can be used to expand this 3D textural analysis to nanoscale crystals in volcanic rocks.
Here, we present a 3D reconstruction and quantification of vesicle and crystal textures in pyroclasts of the Masaya Triple Layer eruption, a highly explosive Plinian eruption of Masaya caldera, Nicaragua. Images and observations of vesicle textures at the micro-scale were acquired using X-ray computed micro-tomography and used to reconstruct the geometrical properties of the connected pore network, including connectivity, tortuosity and the throat-pore size ratio. X-ray ptychography was used to perform a 3D textural analysis of nanoscale crystals within the groundmass of clasts. These data were used to reconstruct conduit processes and evaluate the impact of syn-eruptive crystallisation, vesiculation and outgassing on magma rheology and fragmentation. Our results provide insight into the driving mechanisms of highly explosive, basaltic Plinian activity, and also highlight the potential of using multi-scale 3D imaging techniques to analyse textural features in pyroclasts and investigate controls on eruptive style.
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Mar 2025
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I13-1-Coherence
I13-2-Diamond Manchester Imaging
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Christoph
Rau
,
Darren J.
Batey
,
Shashidhara
Marathe
,
Leonard
Turpin
,
Kudakwashe
Jakata
,
Silvia
Cipiccia
,
Isabel
Anthony
,
Roberto
Volpe
,
Claus-Peter
Richter
,
Alessandra
Carriero
,
Maud
Dumoux
,
Jurgen E.
Schneider
,
Erica
Dall'Armellina
,
Marc W.
Holderied
,
Jan
Van Den Bulcke
Open Access
Abstract: We report about the experimental work related to hierarchical structures at the Diamond I13L beamlines. The I13-2 Imaging and I13-1 Coherence beamlines provide imaging with micro- and nano-resolution. The Diamond II upgrade for the synchrotron source and the OCTOPI upgrade for I13L provide new opportunities for expanding the existing scientific areas in multiscale and operando imaging. We describe the scientific research benefitting from the instrumental upgrade. Comparable recording times across all length scales will enable hierarchical operando imaging. With the implementation of automated high-throughput data acquisition and analysis, large numbers of samples will be analyzed.
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Nov 2024
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I13-2-Diamond Manchester Imaging
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Carlos
Navarrete-Leon
,
P. Stephen
Patrick
,
Adam
Doherty
,
Harry
Allan
,
Silvia
Cipiccia
,
Shashidhara
Marathe
,
Kaz
Wanelik
,
Michela
Esposito
,
Charlotte K.
Hagen
,
Alessandro
Olivo
,
Marco
Endrizzi
Diamond Proposal Number(s):
[30748]
Open Access
Abstract: Two-directional beam-tracking (2DBT) is a method for phase-contrast imaging and tomography that uses an intensity modulator to structure the X-ray beam into an array of independent circular beamlets that are resolved by a high-resolution detector. It features isotropic spatial resolution, provides two-dimensional phase sensitivity, and enables the three-dimensional reconstructions of the refractive index decrement, δ, and the attenuation coefficient, μ. In this work, the angular sensitivity and the spatial resolution of 2DBT images in a synchrotron-based implementation is reported. In its best configuration, angular sensitivities of ∼20 nrad and spatial resolution of at least 6.25 µm in phase-contrast images were obtained. Exemplar application to the three-dimensional imaging of soft tissue samples, including a mouse liver and a decellularized porcine dermis, is also demonstrated.
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Sep 2024
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