bluuebunny/crossref_metadata_2025 huggingface dataset:
Detent force suppression of permanent magnet linear synchronous motor based on a V‐shaped tooth‐slot structure
Authors: Lan Zhiyong , Chen Lifang , Xiao Xinhui , Luo Yuanjun , Deng Meijun , Zhu Shangfeng
Published: December 2022

Given the existence of detent force, the positioning accuracy of permanent magnet linear synchronous motor (PMLSM) with an iron core worsens in its application in the field of the precision drive. To address this problem, a method is proposed to weaken the detent force of PMLSM with a V‐shaped tooth‐slot structure. The models of the detent force, including the cogging force and end force, are established theoretically. The analytical expressions of cogging force and end force are obtained by analysing the ripple rule of the motor. Then, the tooth‐slot surface of the motor with the V‐shaped tooth‐slot structure conducts infinitesimal processing. The relationship between cogging force, end force, and the V‐shaped depth of the V‐shaped tooth‐slot PMLSM is deduced, respectively, using the integration method. Furthermore, Ansoft finite element simulation software Maxwell module is used to compare the conventional PMLSM, V‐shaped magnetic pole PMLSM, and V‐shaped tooth‐slot PMLSM. The comparison reveals that the V‐shaped tooth‐slot structure has the excellent characteristic of increasing the average value of thrust while reducing the ripple of thrust caused by detent force. Finally, prototype fabrication and experiments are conducted to verify the correctness and feasibility of the proposed method.
Eurasian otterLutra lutradistribution and habitat use in a Mediterranean catchment managed for the control of invasive giant reedArundo donax
Authors: Dettori Ettore Emanuele , Balestrieri Alessandro , Zapata-Pérez Víctor Manuel , Bruno Daniel , Rubio-Saura Nuria , Robledano-Aymerich Francisco
Published: December 2022

We assessed the distribution and habitat use of Eurasian otterLutra lutraon the middle course of the River Segura and its tributaries (Murcia, SE Spain) within the framework of the project LIFE13BIO/ES/001407 RIPISILVANATURA (2014–2019). Between April 2016 and June 2018, we surveyed for otter spraints 42 sampling stretches (mean length ± SD = 0.5 ± 0.2 km), covering a 109.8 km long section of the river. The study time frame coincided with the main restoration activities of the LIFE project, consisting in the eradication of widespread, invasive alien giant reedArundo donaxand plantation of autochthonous riparian vegetation. Otter habitat preferences were assessed by measuring ten environmental parameters potentially affecting its occurrence. The relationship between the presence/absence of the otter and habitat variables was evaluated by both linear multiple regression and non-parametric random forest regression model. Otters preferred river stretches crossing forested areas, avoided polluted waters and their occurrence was inversely related to the width of the emerged aquatic vegetation, mostly consisting ofArundoreed beds. Moreover, in managed stretches, otter marking intensity increased after the removal of alien reeds and was higher in RIPISILVANATURA restored transects (1.18 spraints/100 m) than in the downstream, unmanaged half of the watercourse (0.76 spraints/100 m). The combined effects of water pollution and giant reed spread may alter fish distribution and abundance, reducing prey availability to otters. The improvement of chemical and physical habitat quality of streams through alien reeds removal seems thus pivotal to enhance the recovery of otter's populations in the south-eastern Iberian Peninsula.
Oilseeds development in Morocco in the current international context
Authors: Azenzem Rachid
Published: December 2022

Oilseeds are grown mainly for the extraction of vegetable oils and for its by-products needed in livestock feed and in other industrial uses. The oils obtained from them are becoming a staple food used in daily cooking in several countries, and as a result the world demand is constantly increasing. This situation, combined with the exponential increase in the world population and other cyclical factors, is leading to a surge pricing, especially in importing countries. This increase in prices is fueled by soaring oil prices and disruption in supplies following Covid-19 pandemic and geopolitical tensions in the Black Sea. Morocco is directly impacted by these fluctuations given that the country imports almost its total needs in vegetable oils, oilseeds and meals. The high dependence on imported vegetable oils and oilseed products has a detrimental effect on the economy of Morocco and weighs heavily on the country’s trade balance. Considering their increasingly important role in society, the development of a local oilseed sector to reduce Morocco’s dependence on imports and cope with the vagaries of global markets has never been more topical in the current context of sustainable agriculture and food sovereignty.
Densité osseuse et radiographie panoramique : incidences orthodontiques
Authors: Couraud Pierre
Published: December 2022

Introduction : le panoramique dentaire tient une place prépondérante dans l'investigation radiologique et le diagnostic en orthodontie. Les examens 3D comme le CBCT font office de gold standard dans l'étude de la qualité osseuse mais tous nos cabinets n'en sont pas encore équipés. Par sa simplicité d'utilisation et d'analyse le panoramique dentaire est quant à lui présent dans l'immense majorité de nos cabinets. Par des outils simples applicables sur un cliché panoramique il est possible d'obtenir une évaluation préliminaire de la densité osseuse. C'est dans ce contexte que nous avons souhaité étudier la densité osseuse sur panoramique et en connaître les intérêts dans notre pratique quotidienne.

Conclusions : l'estimation de la densité osseuse sur radiographie panoramique est utile pour la planification de nos traitements d'orthodontie, le choix des dimensions des mini-vis d'ancrage, la durée, la stabilité du traitement et la détection de l'ostéoporose.
Autotransplantation d'une dent surnuméraire en place d'incisive géminée, une décision thérapeutique construite
Authors: Dekester Guillaume , Pottier Thomas , Sorel Olivier
Published: December 2022

L'intérêt de cette présentation d'un cas clinique réside dans la prise en compte des données de la littérature pour établir des choix complexes ainsi que pour utiliser des technologies numériques innovantes.

La malocclusion de ce patient est caractérisée par des rapports molaires de classe III d'Angle complète mais avec un surplomb incisif quasi normal sans compensation dentaire. L'équilibre squelettique est hyperdivergent avec une tendance à la classe III. L'encombrement à l'arcade mandibulaire est très marqué... Ce qui caractérise le plus ce patient, c'est la présence d'une incisive surnuméraire en position vestibulaire (11*) devant l'incisive latérale droite (12), une anomalie de forme de l'incisive centrale maxillaire gauche (21) et l'absence compensée des premières molaires maxillaires.

L'établissement de l'arbre décisionnel qui nous a conduit à extraire la 21 avec autotransplantation de la 11* surnuméraire, s'appuie sur les données de la littérature ainsi que sur la collaboration multidisciplinaire et illustre ainsi une démarche thérapeutique exemplaire.
L'expansion maxillaire avec ancrage osseuxchez l'adulte : description et cas clinique
Authors: Cuevas Paola
Published: December 2022

L'objectif est de présenter dans un premier temps l'expansion maxillaire par ancrage osseux en décrivant trois dispositifs puis dans un deuxième temps, de montrer un cas clinique avec un traitement sans chirurgie d'un patient de 18 ans présentant une insuffisance maxillaire transversale et postéro-antérieure et une infraclusion antérieure. Le patient fût traité par disjonction rapide inter-maxillaire à appui dento-squelettique, traction postéro-antérieure du maxillaire et multiattaches. L'ancrage squelettique a permis une correction de l'insuffisance maxillaire, de l'occlusion inversée et de l'infraclusion.

Les implants d'ancrage ont permis d'éviter les effets secondaires d'un ancrage dentaire, de libérer d'autres zones de résistances et ont favorisé une ventilation nasale.

Pour conclure, l'expansion rapide sur mini-implants peut être aujourd'hui une alternative à la disjonction assistée chirurgicalement chez le jeune adulte.
Utilisation de la réalité virtuelle pour l’apprentissage de la lecture critique d’article en santé
Authors: Frigo Léa , Kronovsek Téo , Perrochon Anaïck
Published: December 2022

Contexte: La réalité virtuelle est utilisée dans de nombreux enseignements et de différentes manières en pédagogie médicale mais jusqu’à présent jamais pour l’apprentissage de la lecture critique d’article. But : Évaluer l’utilisabilité et l’intérêt de la réalité virtuelle, en complément de l’analyse de la version textuelle d’un article, lors d’un enseignement de lecture critique d’article. Méthodes : Seize étudiants en troisième année de masso-kinésithérapie à l’Université de Limoges ont bénéficié d’un enseignement de lecture critique d’article à distance dans le cadre d’un dispositif recourant à la réalité virtuelle. Des questionnaires les interrogeaient sur leur ressenti, sur les effets secondaires (VRSQ), sur l’utilisabilité du système (SUS) et sur l’expérience perçue d’utilisateur (AttrackDiff 2). Une grille de lecture critique d’article a été remplie par les étudiants après lecture d’un article scientifique, puis complétée après le module en réalité virtuelle, donnant deux scores de performance. Le parcours d’apprentissage des étudiants dans l’expérience virtuelle a également été analysé. Résultats : Les apprenants ont obtenu des scores significativement supérieurs après la visualisation du module en réalité virtuelle (respectivement 13,1 ± 3,0 et 14,3 ± 3,1, p < 0,05). Les étudiants ont estimé que l’outil facilitait la compréhension d’une étude scientifique et qu’il augmentait la motivation et la concentration. L’utilisabilité et l’attractivité du module en réalité virtuelle était satisfaisantes, malgré la présence de quelques effets indésirables. Conclusion : La réalité virtuelle semble être un outil intéressant à utiliser dans le cadre du développement de la capacité d’analyse critique, notamment dans un enseignement à distance en ligne.
Impact du degré d’interdépendance entre élèves visé par les formats de jeu sur l’engagement en EPS : l’exemple du badminton
Authors: Dieu Olivier , Llena Clément , Derigny Thibaut , Potdevin François
Published: December 2022

Promouvoir l’activité physique (AP) en éducation physique (EP) repose, en partie, sur l’intérêt des élèves envers les situations proposées. L’EP poursuivant également la finalité de faire coopérer les élèves, concevoir des formats de jeu collectifs visant l’interdépendance entre élèves permet-il simultanément de les engager ? Considérant l’engagement comme un phénomène émergeant d’une interaction spécifique entre l’individu et son environnement, cette étude compare les effets de quatre formats de badminton, qui se distinguent par le degré d’interdépendance visé entre élèves, sur l’AP et l’intérêt en situation (IS) de 101 lycéens. L’engagement psychologique a été mesuré à l’aide d’une échelle validée d’intérêt en situation (IS) et des accéléromètres ont permis d’évaluer la quantité d’AP. Nos résultats montrent que la modification des formats de jeu n’impacte que deux dimensions de l’IS : la nouveauté et le plaisir instantané. En termes d’AP, si on ne note aucune différence entre les formats de double, des différences ont été relevées entre les formats de simple. La « ronde italienne » plait et met davantage en mouvement les élèves que la « montante descendante ». Ainsi cette étude suggère qu’un format de jeu, qui vise une interdépendance de buts entre élèves, offre une perspective de promotion de l’AP.
Feature recognition and machine learning in finite element models through a clustering algorithm
Authors: Premkumar Sunil , Jebaseelan Davidson , Annamalai Krishnamoorthy
Published: December 2022

The feature identification of the CAD model is a significant task in any CAD algorithm. Enormous computational time, huge memory allocation, lack of understanding in computational geometry, etc., are some of the complications faced while implementing the feature recognition algorithms. This paper represents a clustering algorithm procedure in finite element models, which is the predominant component in analysis methodology. This study performs the clustering of data groups through density-based clustering algorithms such as mean shift clustering and K-means clustering algorithm. In addition to that, experimental evaluation based on the structured algorithm procedure for identifying the features of CAD geometries is investigated. Finally, the study evaluates the performance of the proposed structured algorithm and its efficiency in terms of both computational time and computational memory.
Essential Surgical Anatomy for Facelift
Authors: Uppal Sandeep
Published: December 2022

It is crucial for a facelift surgeon to have a comprehensive understanding of ageing-related changes on the volume, elasticity, and relative position of various facial tissues and layers. These changes lead to an alteration in the surface topography, contour, and ultimately shape of the face. The depressions and sagging of tissues created as a result of ageing then has a bearing on one's perceived age. This article describes the various layers of the face and neck affected by ageing. The fat compartments, superficial musculoaponeurotic system (SMAS), potential facial spaces, facial ligaments, and facial nerve are discussed in detail. Safe and effective execution of facelift requires a thorough understanding of the intricate relationship between the various layers of face and neck, in particular the path of facial nerve, as it negotiates between these layers. The emphasis of this article is on integrating this knowledge to generate practical tips for safe dissection, effective tissue movement, and repositioning during various type of facelift procedures.
Deep Neck Lift: Defining Anatomical Problems and Choosing Appropriate Treatment Strategies
Authors: Marten Timothy , Elyassnia Dino
Published: December 2022

A well-contoured neck is an artistic imperative to an attractive and appealing appearance. A good neckline conveys a sense of youth, health, fitness, confidence, and vitality and lends an appearance of decisiveness, sensuality, and beauty. Neck improvement is of high priority to almost every patient seeking facial improvement, and the results of “face lift” procedures are judged largely by the outcome obtained in the neck. If the neck is not sufficiently improved, our patients will often feel we have failed them. Despite the fact that it is a common practice, it is not enough to perform submental liposuction and tighten the skin and platysma in most patients as such an approach ignores a number of anatomical problems present in many patients seeking neck improvement including excess subplatysmal fat, large submandibular glands, and digastric muscle hypertrophy and malposition. Removing subcutaneous fat and tightening skin and platysma over these problems does not correct them, and the presence or absence of each must be looked for in order to create and apply an appropriate surgical plan. Success or failure in treating the neck lies in the diagnosis of underlying problems and the application of a logical surgical plan to correct them. Any surgeon capable of identifying the anatomic basis of patient problems and forming a sound plan for their correction will achieve excellent outcomes.
Tesla Facelifting Using Energy Devices during Rhytidectomy
Authors: Gentile Richard
Published: December 2022

Tesla facelifting is the process of utilizing energy devices as surgical tools during rhytidectomy and neck lifting. Devices used for Tesla face and neck lifting include fiber lasers, radio frequency devices, high-frequency ultrasound, and plasma energy devices. Advantage of Tesla face and neck lifting include better visualization for surgical intervention due to reduced bleeding, better access to hard to access facial and neck locations, and long-term skin tightening from the subdermal energy treatment.
Variation in flowering time and flowering date stability within a cultivar of French serradella
Authors: Haling Rebecca E. , Goward Laura , Stefanski Adam , Simpson Richard J.
Published: December 2022

Context Opportunity exists to expand serradella (Ornithopus spp.) use onto heavier, duplex soil types in permanent pasture environments of south-eastern Australia. This requires cultivars with appropriate flowering times and flowering-date stability (i.e. flowering at the same date in spring regardless of timing of the autumn break). Aim This work examined evidence of variation in flowering date and flowering-date stability in the NSW southern tablelands for a widely-used French serradella (O. sativus) cv. Margurita. Methods Seed (sourced from a commercial supplier) was sown 21 March 2019 (Canberra, ACT) and 231 individual plants were monitored for time to first flower. A subset of plants exhibiting ‘early’ or ‘late’ flowering were identified and their seeds collected. In 2020, seed from ~15 plants from each selection was sown in Canberra in late March and early May to represent an ‘early’ and a ‘later’ break of season (n = 3). Key results In the early-sown treatment, ‘early-flowering’ selections typically reached the median date of first flower (50%-flowering) from mid- to late August, while ‘late-flowering’ selections reached 50%-flowering early- to mid-September. When sown later, the ‘early-flowering’ selections began flowering from mid- to late September, while the ‘late-flowering’ selections flowered mid-September to early October. The ‘early’ selections exhibited greater flowering-date instability than ‘late’ selections and flowered particularly early when sown early. This indicated diversity within cv. Margurita for flowering-time control (e.g. vernalisation and/or photoperiod requirements). Implications Evaluating cultivars of serradellas for flowering date and flowering date stability in their target environment(s) is essential to ensure cultivars are suitably adapted to these environments.
Dialectics, power dynamics, and undercurrents of meaning: using psychotherapeutic strategies in primary care with trans and gender-diverse clients
Authors: Waldron Elizabeth , Solonsch Lucy , Stone Louise
Published: December 2022

Trans and gender-diverse individuals experience poor mental health, and face significant barriers when trying to access appropriate mental health care. Most seek treatment from mainstream primary care services, who have an ethical duty to provide care to all. Primary care practitioners can ameliorate traumatic harms by identifying helpful strategies and avoiding inappropriate or harmful strategies. However, there is limited robust, culturally sensitive evidence informing clinicians about the appropriateness and efficacy of psychological interventions for trans and gender-diverse clients. This forum article argues that the epistemological and ontological frameworks underlying psychotherapies can impact the therapeutic relationship, and are therefore important factors to consider in primary care practice with trans and gender-diverse clients. Our paper synthesises selected psychotherapies into four clusters. Each cluster is accompanied by discussion of the potential or demonstrated benefits and limitations of the underlying framework, in the context of primary care with trans and gender-diverse clients. We also explore power dynamics in therapeutic relationships with trans and gender-diverse clients, and the challenges these factors pose to developing a shared understanding of the client’s needs and preferences. The article concludes with some practical considerations for managing these issues in primary care.
Human septins organize as octamer-based filaments and mediate actin-membrane anchoring in cells
Authors: Martins Carla Silva , Taveneau Cyntia , Castro-Linares Gerard , Baibakov Mikhail , Buzhinsky Nicolas , Eroles Mar , Milanović Violeta , Omi Shizue , Pedelacq Jean-Denis , Iv Francois , Bouillard Léa , Llewellyn Alexander , Gomes Maxime , Belhabib Mayssa , Kuzmić Mira , Verdier-Pinard Pascal , Lee Stacey , Badache Ali , Kumar Sanjay , Chandre Cristel , Brasselet Sophie , Rico Felix , Rossier Olivier , Koenderink Gijsje H. , Wenger Jerome , Cabantous Stéphanie , Mavrakis Manos
Published: December 2022

Septins are cytoskeletal proteins conserved from algae and protists to mammals. A unique feature of septins is their presence as heteromeric complexes that polymerize into filaments in solution and on lipid membranes. Although animal septins associate extensively with actin-based structures in cells, whether septins organize as filaments in cells and if septin organization impacts septin function is not known. Customizing a tripartite split-GFP complementation assay, we show that all septins decorating actin stress fibers are octamer-containing filaments. Depleting octamers or preventing septins from polymerizing leads to a loss of stress fibers and reduced cell stiffness. Super-resolution microscopy revealed septin fibers with widths compatible with their organization as paired septin filaments. Nanometer-resolved distance measurements and single-protein tracking further showed that septin filaments are membrane bound and largely immobilized. Finally, reconstitution assays showed that septin filaments mediate actin–membrane anchoring. We propose that septin organization as octamer-based filaments is essential for septin function in anchoring and stabilizing actin filaments at the plasma membrane.
Improving the spectral resolution and measurement range of quantum microwave electrometry by cold Rydberg atoms
Authors: Zhou Fei , Jia Fengdong , Liu Xiubin , Yu Yonghong , Mei Jiong , Zhang Jian , Xie Feng , Zhong Zhiping
Published: December 2022

We theoretically and experimentally studied quantum microwave electrometry in a cold atomic system using Rydberg electromagnetic induction transparency (EIT) and Autler–Townes splitting (EIT-AT splitting). In cold atoms, a spectral linewidth of ∼500 kHz for EIT was achieved owing to a significant reduction in residual Doppler width, i.e. by at least an order of magnitude, compared to that in vapor cells at room temperature. Therefore, the minimum microwave electric field intensity (E
MW) that can be measured is 430 µV cm−1, which is one order higher sensitivity in the EIT-AT regime than that in vapor cells at room temperature. Unlike microwave electrometry in atomic vapor cells, EIT-AT splitting cannot be observed if E
MW is so large that the EIT-AT splitting interval

Δ

f
m

exceeds the absorption peak width of the cold atom while scanning the frequency of the probe laser (ω

p
). Moreover, EIT-AT splitting can be observed if

Δ

f
m

exceeds the natural linewidth

Γ

eg

of the intermediate states while scanning the coupling laser (ω

c
) and maintains a high spectral resolution with a high signal-to-noise ratio. While scanning ω

c
, the upper microwave electric field intensity is limited by the scanning range of our setup. Using our system, we measure the maximum field to be 21.6 mV cm−1, nearly three times higher than that of 6.8 mV cm−1 while scanning ω

p
. The results indicate that the linear range of E
MW measured using EIT-AT splitting considerably improves in cold Rydberg atoms.
Cr(OH)3 nanosheets@ZIF67 electrocatalysts prepared by electrodeposition method for efficient oxygen evolution reaction
Authors: Chai Yudan , Wei Xuedong , Wang Yufen , Qiao Shuangyan
Published: December 2022

In this paper, a Cr(OH)3 NSs@ZIF67 (NSs = nanosheets) electrocatalyst is prepared on foam Ni via a simple and rapid electrochemical deposition method. Excellent electrocatalytic activity of Cr(OH)3 NSs@ZIF67 is demonstrated. It can use the overpotential of 281 mV and 390 mV respectively to drive 10 mA cm−2 and 50 mA cm−2. It is observed that the Cr(OH)3 NSs@ZIF67 electrode has the highest initial current density at 1.57 V compared with the other two monomer electrodes and shows excellent stability at the end of 60 000 s. It has the largest electrochemical activity specific surface and lowest charge-transfer resistance, and M–O bonds (M = Co, Cr) and shifting of binding energy peaks at the interface lead to more active sites and more efficient electron transfer for oxygen evolution reaction. This work highlights the construction of highly efficient composite electrocatalysts composted of low-dimensional non-precious transition metal compounds and metalorganic frameworks, promoting the development of low-cost non-noble metal composites in energy chemistry.
The constraint of plasma power balance on runaway avoidance
Authors: McDevitt Christopher J. , Tang Xian-Zhu , Fontes Christopher J. , Sharma Prashant , Chung Hyun-Kyung
Published: December 2022

In a post-thermal-quench plasma, mitigated or unmitigated, the plasma power balance is mostly between collisional or Ohmic heating and plasma radiative cooling. In a plasma of atomic mixture

{

n
α

}

with α labeling the atomic species, the power balance sets the plasma temperature, ion charge state distribution

{

n
α
i

}

with i the charge number, and through the electron temperature

T

e

and ion charge state distribution

{

n
α
i

}
,

the parallel electric field

E
∥

.

Since the threshold electric field for runaway avalanche growth

E

a
v

is also set by the atomic mixture, ion charge state distribution and its derived quantity, the electron density

n

e

,

the plasma power balance between Ohmic heating and radiative cooling imposes a stringent constraint on the plasma regime for avoiding and minimizing runaways when a fusion-grade tokamak plasma is rapidly terminated.
Optimizing analytical research on the current leads characteristics to the superconducting electromagnets
Authors: Sosnowski J
Published: December 2022

In the paper is proposed new analytical approach to the optimization of the characteristics of the current leads to the superconducting electromagnets, basing on the analytical solution of the heat diffusion equation in stationary as well as dynamic, one dimensional case. Then temperature distribution in copper current leads to superconducting electromagnets through which flows current has been determined for monolithic lead with thermal intercept. The values of the low temperature losses, i.e. heat leak flowing through the cold end of lead at FEL-s type construction were determined as the function of current, while minimum of this leakage was found for various leads geometries. This new analytical approach allows to follow, in more visible form than advanced numerical calculations, the influence of physical parameters on the current leads operation.
Superconducting Phase shifter design for the afterburner at the European XFEL.
Authors: Grattoni V. , Baader J. E. , Casalbuoni S.
Published: December 2022

At the European XFEL, we are designing a superconducting afterburner for the SASE2 hard X-ray beamline. It will consist of a series of five undulator modules plus a pre-series one called S-PRESSO. One module corresponds to two superconducting undulator (SCU) coils of 2m length plus one phase shifter. Such an afterburner will enable photon energies above 30 keV. We foresee to install superconducting (SC) phase shifters in each undulator module to keep the correct phase delay between the electron beam and photon beam. In this contribution, we present the required SC phase shifter parameters to enable operation in the electron beam energy range 11.5-17.5 GeV. We also analyze different magnetic designs satisfying the calculated specifications.
An analytical study to determine the mechanical tolerances for the afterburner superconducting undulators at EuXFEL
Authors: Grattoni V. , Casalbuoni S. , Marchetti B.
Published: December 2022

At the European XFEL, a superconducting afterburner is planned for the SASE2 hard X-ray beamline. It will consist of 5 undulator modules plus a pre-series module called S-PRESSO. Within each module, two superconducting undulators (SCU) 2 m long are present. Such an afterburner will enable photon energies above 30 keV.

The magnetic field of the SCU determines the quality of the electron beam trajectory and the free-electron laser (FEL) radiation. The mechanical accuracy of the SCU determines its magnetic field quality. In this contribution, we present the mechanical errors and an analytical study to determine the tolerances for our SCUs.
Development of cryogenic undulators and measurement equipment for PETRA IV
Authors: Abenhaim J , Bolat H , Schöps A , Vagin P , Tischer M
Published: December 2022

DESY is planning to upgrade its current storage ring PETRA III into the ultra-low emittance photon source PETRA IV. The current H6BA cell design for the PETRA IV lattice will allow for insertion devices of up to 4 m length in the standard straight sections. In order to allow some beamlines to not only benefit from the performance improvements by the machine but also from the undulators, we started looking into using advanced undulator schemes as well. We decided to start the design of cryogenically cooled permanent magnet undulators (CPMUs) based on (Nd,Pr)FeB magnets for PETRA IV, since this technique has already been proven successfully by various other facilities. We will present the planned design for the magnet keepers, the pole tuning mechanism as well as a testbed for keepers under cryogenic conditions. We will also show a preliminary design for the in-situ Hall-probe bench currently developed for the upcoming PETRA IV CPMUs.
Characterization of helical APPLE X undulators with 90 mm period for the European XFEL
Authors: Yakopov M. , Calvi M. , Casalbuoni S. , Englisch U. , Karabekyan S. , Liang X. , Schmidt T.
Published: December 2022

European XFEL is going to provide full polarization control in the soft X-ray SASE line (SASE3). For this purpose, four helical APPLE X undulators with 90 mm period are installed downstream with respect to the planar undulators of the SASE3 undulator line consisting of 21 planar undulators with 68 mm period. In this contribution, the measurement technique, as well as the results of the measurements and tuning of the APPLE X undulators performed at European XFEL are presented.
Commissioning experience with two in-vacuum undulators at PETRA III
Authors: Schöps A , Vagin P , Keil J , Tischer M
Published: December 2022

In 2018 the high energy X-ray beamlines P07[1] and P21b[2] at DESY’s storage ring PETRA III received new undulators. The two identical devices were built by an industry collaboration of Research Instruments GmbH and Kyma S.p.A. according to DESY’s specifications. They have a magnetic length of 4 m, a period length of 21.2 mm and a deflection parameter K of 1.41 at a gap of 7.0 mm. We report about experience during magnet tuning, the final acceptance measurements and the commissioning in the accelerator tunnel.
Conceptual Design of a Liquid Helium Vertical Test-Stand for 2m long Superconducting Undulator Coils
Authors: Marchetti B. , Abeghyan S. , Baader J. , Barbanotti S. , Casalbuoni S. , Di Felice M. , Eckoldt H.-J. , Englisch U. , Grattoni V. , Grau A. , Hauberg A. , Jensch K. , La Civita D. , Lederer S. , Lilje L. , Ramalingam R. , Schnautz T. , Vannoni M. , Yakopov M. , Zimmermann R. , Ziolkowski P.
Published: December 2022

Superconducting Undulators (SCUs) can produce higher photon flux and cover a wider photon energy range compared to permanent magnet undulators (PMUs) with the same vacuum gap and period length.

To build the know-how to implement superconducting undulators for future upgrades of the European XFEL facility, the test stand SUNDAE1 for the characterization of SCU is being developed. The purpose of SUNDAE1 is the training, tuning and development of new SCU coils by means of precise magnetic field measurements.

The experimental setup will allow the characterization of magnets up to 2m in length. These magnets will be immersed in a Helium bath at 4K or 2K temperature.

In this article, we describe the experimental setup and highlight its expected performances.
The new PTB beamline for vacuum-ultraviolet radiometry
Authors: Ogor O , Kroth U , Kaser H , Krzyzagorski M , Gottwald A
Published: December 2022

At the Metrology Light Source, a 630 MeV electron storage ring for the use of synchrotron radiation for metrology applications, a new beamline is dedicated to radiometry in the vacuum-ultraviolet spectral range. The emphasis lies on the traceability of measurements and profound uncertainty analysis. To replace the previously existing normal incidence monochromator beamline which serviced for more than 20 years now at different facilities, a newly designed 2 m off-plane Eagle monochromator beamline concept was developed. Different reflective coatings for mirrors and gratings in combination with order-sorting filters ensure highest spectral purity of the monochromatized radiation in combination with optimized photon flux characteristics. The beamline is planned to go into full operation in late 2022.
HESEB: The Helmholtz state-of-the-art Soft-X-Ray Undulator beamline at SESAME
Authors: Abbadi Anas , Attal Maher , Bahrdt Johannes , Drube Wolfgang , Eberhardt Wolfgang , Martin Esser Frank , Follath Rolf , Froideval Annick , Fatih Genisel Mustafa , Groetsch Daniel , Rahman Hasoneh Abdel , Huck Maryam , Huttel Erhard , Kanngießer Birgit , Knaack Sebastian , Krueger Ole , Lausi Andrea , Lehner Frank , Lörgen Marcus , Meseck Atoosa , Momani Yazeed , Al Najdawi Mohammad , Natour Ghaleb , Paolucci Giorgio , Rial Edward , Roschka Michael , Scheer Michael , Schramm Barbara , Schuppler Stefan , Shehab Maher , Siewert Frank , Tiemann Christoph , Weissig Annette
Published: December 2022

SESAME and a consortium of five Helmholtz Centers are designing and installing a state-of-the-art soft X-Ray undulator beamline at the SESAME light source in Amman, Jordan. Funding is provided by the Helmholtz Association over a four year project cycle that started in January 2019. This is an interim report covering the first 36 months of the project where the construction and installation has been almost completed and commissioning and characterization of the beamline is about to start. Additionally, seminars, workshops, and a training program are part of the project aimed at establishing a broad user community.
A review on the High-Dynamic Double-Crystal Monochromator for Sirius/LNLS
Authors: Geraldes R R , de Brito Neto J L , Saveri Silva M , de Albuquerque G S , Luiz S A L , Pinto A C , Rigamonti Junior H , Eleotério M A S
Published: December 2022

The High-Dynamic Double-Crystal Monochromator (HD-DCM) started to be developed in 2015 by the Brazilian Synchrotron Light Laboratory (LNLS) for the 4th-generation light source Sirius. The reason for the unique and innovative control-based architecture was twofold, namely: 1) reaching the unprecedented target of 10 nrad RMS (root mean square) (1 Hz - 2.5 kHz) in crystals parallelism for a vertical-deflection DCM, to comply with the smaller new-generation source sizes; and 2) unlocking the potential of high-stability fixed-exit continuous energy scans, creating unmatching spectroscopy capabilities that benefit from the higher new beam brightness. The outcome is a machine built on essential high-precision mechatronics principles, with an integrated design for optimized dynamics, actuation, metrology, and thermal aspects. The first two units are operational at the MANACA (protein crystallography) and the EMA (extreme conditions and spectroscopy) undulator beamlines. This work reviews the key aspects of this new technology and presents experimental commissioning results at the beamlines, including high-quality energy continuous fly-scans up to 500 eV/s over 1 keV that demonstrate the good performance for X-ray spectroscopy by keeping inter-crystals stability below 15 nrad RMS up to 10 kHz. Preliminary EXAFS data collected at the EMA beamline at 1 keV/s is also shown. Furthermore, a discussion is held about the required beamline integration level, since the high-end experiments demand appropriate control strategies, data acquisition, triggering and performance capabilities, particularly concerning the source, the sample environment, and the detectors.
Design of a plane grating with multilayer coating for the soft X-ray tomography beamline
Authors: Su Yi-Jr , Yin Gung-Chian , Hsu Ming-Ying , Fu Huang-Wen , Fung Hok-Sum
Published: December 2022

An alternate multilayer plane grating has been designed for the soft X-ray tomography beamline. At this beamline, a grating with 600 line/mm and Au coating has already been set up to serve the energy range from 260 eV to 1200 eV. To fit the original optical design, a varied-line-spacing plane grating optimized at 2473 eV will be used in this beamline. The groove depth is 2.5 nm and its duty cycle is 0.5. The B4C/Mo alternate layers with period 30 are selected to enhance diffraction efficiency in the energy range 1100 eV -- 2600 eV. The varied-line-spacing plane grating paired with a matched multilayer plane mirror constitutes a monochromator to provide energetic photons. Based on the designed multilayer conditions, the calculated diffraction efficiency of alternate multilayer varied-line-spacing plane grating is about 0.24 at 2473 eV; the calculated photon flux is about 2.3 × 1011 photons/s. The resolving power is about 1670; the openings of the entrance and exit slits are 25 and 50 μm respectively.
Soft X-ray grating monochromators as a source of spatial coherence degradation: A wave-optical approach
Authors: Khubbutdinov Ruslan , Seyrich Martin , Bagschik Kai
Published: December 2022

We present wave-optical simulations and a coherence analysis of the photon beam transported through a soft X-ray beamline, paying particular attention to a focusing varied line spacing (VLS) plane grating monochromator (PGM). We show that this beamline optical element used in several soft X-ray beamlines at synchrotron sources and free-electron lasers can cause a non-negligible spatial coherence degradation. We demonstrate that the origin of this effect arises from the coupling between spatial and spectral properties of the photon beam generated by the grating. The latter implies that space and frequency dependencies are not separable after such a dispersive element. It is shown which parameters are essential for this effect and how they are linked to each other.
Strategies to minimize beam and sample vibration-induced instabilities at the microfocus MX XAIRA beamline at ALBA
Authors: Quispe Marcos , Garriga Damià , González Nahikari , Šics Igors , Colldelram Carles , Nicolas Josep , Juanhuix Judith
Published: December 2022

The performance of microfocus beamlines, and ultimately the quality of the diffraction data, is very sensitive to vibrations affecting the optical elements and the sample stages and holder. We report here the strategies applied in the design of the microfocus MX XAIRA beamline at ALBA synchrotron to mitigate the effects of two relevant sources of vibrations: circulation of LN2 flow to evacuate the thermal load on the monochromator and cryocooling gas stream being blown on the sample. The internal shape and size of the two cooling pads that clamp the monochromator optics have been designed to minimize the turbulences in the liquid nitrogen flow while maximizing heat transfer. Computational Fluid Dynamics (CFD) simulations and some preliminary metrology tests are presented. Besides, in the end-station, the cryo-cooler is blowing typically a 5-10 L/min flow of nitrogen or helium gas at 100K on the sample, inducing vibrations in the micron range. The optimal geometrical configuration between the sample holder and the cryocooler has been assessed by means of CDF simulations and metrology tests.
Measurement of the Ellipsometric Parameters of Thin Graphene Layers in the Extreme Ultraviolet
Authors: Zuppella P , Samparisi F , Frassetto F , Rigato V , Campostrini M , Poletto L
Published: December 2022

A reflection polarimeter for the XUV (30 – 100 eV) spectral range realized with three ruthenium optics has been designed, developed and tested. The instrument is conceived to be an insertable device, maintaining unaltered the XUV beam propagation direction. For energies greater than ∼55 eV, ruthenium permits to obtain a higher throughput than the one obtainable with gold optics. We propose a procedure to measure properties of graphene: the method uses a reference sample in place of one ruthenium mirror, as consequence the measure does not depend on the optical properties of the two remaining ruthenium mirrors. With this instrument we have performed ellipsometric measurements on thin graphene layers in the 15 – 30 eV spectral range.
The beam stop as an intensity monitor
Authors: Müller L , Walther M , Riepp M , Philippi-Kobs A , Jo W , Roseker W , Bagschik K , Frömter R , Pan R , Lott D , Möller J , Bösenberg U , Hallmann J , Rodriguez-Fernandez A , Scholz M , Ansaldi G , Wrigley J , Zozulya A , Madsen A , Grübel G
Published: December 2022

Free-electron lasers (FELs) provide unique possibilities in investigating matter down to femtosecond time and nanometer length scales, as well as in the regime of non-linear light-matter interaction. Due to the nature of FEL sources, the produced beam is significantly more unstable than beams produced by 3rd generation synchrotrons. As a result, pulse-resolved normalization of measurement data becomes essential and can be challenging. The intensity monitors permanently installed at a facility might indeed accurately measure the pulse intensities at a certain point of the beamline, but cannot precisely normalize experimental data. For example the impact of pointing instabilities and hence different clipping of the beam downstream on the way to the actual experiment is not reflected in the intensity measurement. Here, we show how the integral intensity of the FEL beam transmitted through the sample can be measured by photodiodes providing a proper normalization of measurement data.
Improved Design of a Monochromatic beam Screen Monitor for Taiwan Photon Source Beamlines
Authors: Lee Longlife , Chen Hsin-Wei , Chuang Yu-Chun , Chang Shinh-Hung , Su Yi-Jr , Huang Chi-Yi
Published: December 2022

An X-ray phosphor screen is a standard component at beamlines of Taiwan Photon Source (TPS). It responds to x-rays, re-emitting the energy as visible light. This screen is used as a tool for the coarse alignment of the synchrotron beam. The development of TPS beamlines proceeds to Phase III. Based on the user feedback of Phases I and II, we redesigned the x-ray phosphor screen and utilized it as a fourth screen at beamline TPS 19A. It has a greater ratio of signal to noise than the existing screens and was successfully commissioned in 2021. We plan to introduce it at TPS phase-III beamlines.
Highly Charged Ions for High-Resolution Soft X-ray Grating Monochromator Optimisation
Authors: Hoesch Moritz , Seltmann Jörn , Trinter Florian , Kühn Steffen , Togawa Moto , Steinbrügge René , Bernitt Sonja , Crespo López-Urrutia José R.
Published: December 2022

The energy-resolving performance of a synchrotron radiation monochromator can be characterised by measuring the fluorescence response of a gas in scans across characteristic absorption lines. Here, we describe a method using exceptionally narrow absorption features in the soft x-ray range. The features belong to helium-like ions and examples of the transition 1s → 2p in O6+ and Ne8+ are shown. We describe the instrument PolarX-EBIT and show typical data. A performance with ten times sharper effective feature width, when compared to neutral-gas absorption features, is demonstrated.
Measurement and calculation of scattered Synchrotron Radiation processes at the KARA visible light beamline
Authors: Batchelor D R , Blomley E , Huttel E , Hagelstein M , Mochihashi A , Schuh M , Simon R
Published: December 2022

At KARA a visible light diagnostic beamline is in use to analyse the stored electron beam. Synchrotron light is deflected 90 degrees upwards by a cooled copper mirror, passes through a Quartz UHV window and is then reflected back into the horizontal plane but sideways through a hole in the wall to the diagnostics. Based on experience from similar Infrared beamlines no significant radiation (doserates larger than 0.5µSv/hr) was expected. Nevertheless, a higher radiation level exists but can be shielded with 0.3mm Aluminium foil or 2.0mm of Pyrex reducing the rate to an acceptable level. The presence of the radiation led to further investigation by experiment and calculation. A custom setup using a silicon drift detector (SDD) for energy dispersive spectroscopy showed the radiation to be predominantly Copper K-alpha and is confirmed by FLUKA and other calculations of the scattered Synchrotron radiation.
Efficient Coherent Mode Decomposition for Physical Optics Simulations of Beamlines and Experiments
Authors: Li Ruizi , Chubar Oleg
Published: December 2022

We present simulations of the partially coherent undulator radiation (UR) propagation through several hard X-ray beamlines at NSLS-II, performed with SRW code, adopting two different memory- and CPU-efficient strategies / algorithms for the coherent mode decomposition (CMD). One of these algorithms employs the subtraction of quadratic phase terms from 4D cross spectral density (CSD) at a non-zero radius of the radiation wavefront curvature, whereas the other one applies the CMD at / near a radiation beam waist, where the radiation wavefront is typically “flat”. We show that, when performing the CMD on the 4D CSD of the partially coherent radiation wavefront, the required numbers of grid points of radiation meshes are largely reduced in both cases, compared to standard approaches. This dramatically reduces memory requirements (from TBs typically to several GBs) and improves the time-to-solution of the decomposed modes (from many hours at a parallel execution to several minutes at a sequential execution). Thanks to the implemented algorithms, the propagation simulations of tens or hundreds of thousands coherent wavefronts generated by independent electrons for an undulator-based X-ray beamline at a low- or intermediate- emittance synchrotron light source is reduced to the simulation of over fewer than one thousand major coherent modes obtained from the CMD, which fully recovers the structure of the partially coherent UR before and after the propagation through a beamline. The efficiency and accuracy of the methods is further demonstrated with simulations for two hard X-ray NSLS-II beamlines: HXN and CHX.
Development of CoRDIA: an Imaging Detector for next-generation Synchrotron Rings and Free Electron Lasers
Authors: Marras A , Klujev A , Lange S , Laurus T , Pennicard D , Trunk U , Wunderer C B , Hafiane M L , Hemperek T , Kamilaris T , Krueger H , Wang T , Graafsma H
Published: December 2022

An x-ray imager is being developed for use in diffraction-limited synchrotron rings and continuous wave free electron lasers. The imager is named CoRDIA (COntinuous Readout Digitising Imager Array) and aims at achieving continuous operation at a frame rate in excess of 100kHz. Other goals include single-photon sensitivity at 12 keV (or below), a full well in excess of 10k photon/pixel/image, and a 100μm pixel pitch. The detector ASIC will be compatible with multiple sensor materials to cover different energy ranges. Exploratory prototypes of the readout ASIC (basic circuital blocks) have been manufactured in TSMC 65nm technology: they are presently under test.