In-built resonant structures for precision assembly of X-Ray Optics for 4th Generation Light Sources

As the Diamond Light Source embraces the move towards becoming a fourth generation light source it will require its optics to perform under increasingly demanding conditions. Foremost amongst these conditions will be the increasing powers they are subjected to and the reducing real estate they must perform in. With these new challenges comes the need for greater understanding of how optics are assembled and how consistently this activity is carried out. In this paper, the concept of using passive resonant structures as part of a precision assembly approach for such optics is introduced. Numerical simulation of a passive resonant device comprising tines which are compressed as clamping force is increased is presented, revealing a frequency shift from intermediately fastened to fully tightened. This approach has the potential to provide a robust, game changing improvement to the accuracy of assembly of X-ray optics and subsequently a significant improvement in their performance

On the utility of fluid flow models in the design of heat exchangers for cooling 4th generation X ray optics

As the Diamond Light source moves towards upgrading to a 4th generation source, increasing x-ray powers and reduced focal sizes will require improved cryogenic cooling to ensure that the projected new levels of brilliance are achieved. This will create a greater demand for LN2, if current systems are maintained, laying a greater economic demand on the facility. As in most cases, new designs are tested using thermal-structural finite element simulation, neglecting the contribution of fluid flow. This leaves us without information about the effect of the fluid on the surface of the crystal, along with the efficiency of the flow itself. This results in under optimised cooling systems, leaving cooling capabilities of the system reduced, increasing the consumption of LN2. This paper presents a full fluid-structure-thermal model, showing the full effects of the flow of liquid nitrogen on the system. This paper will discuss this model in comparison to a conventional thermal-structure model

Effect of clamping force on distortion of the optical surface of monochromators during assembly

As Diamond Light Source embraces the move towards becoming a fourth-generation light source its optics will be required to perform under increasingly demanding conditions. Foremost amongst these conditions will be the increasing power densities the optics are subjected to and the reducing real estate they have to perform in. With these new challenges comes the need for greater understanding of how optics are assembled and how consistently the activity is carried out. In this paper, the effect of bolt pretension during assembly of monochromators on distortion of the optical surface is investigated through numerical simulation. The results reveal skewed convex distortion of the optical surface in the meridional direction when uneven clamping force is applied, highlighting the importance of taking the potential for distortion of the optical surface due to clamping force into consideration

Beyond the Langevin horn: transducer arrays for the acoustic levitation of liquid drops

The acoustic levitation of liquid drops has been a key phenomenon for more than 40 years, driven partly by the ability to mimic a microgravity environment. It has seen more than 700 research articles published in this time and has seen a recent resurgence in the past 5 years, thanks to low cost developments. As well as investigating the basic physics of levitated drops, acoustic levitation has been touted for container free delivery of samples to a variety of measurements systems, most notably in various spectroscopy techniques including Raman and Fourier transform infrared in addition to numerous X-ray techniques. For 30 years, the workhorse of the acoustic levitation apparatus was a stack comprising a piezoelectric transducer coupled to a horn shaped radiative element often referred to as the Langevin horn. Decades of effort have been dedicated to such devices, paired with a matching and opposing device or a reflector, but they have a significant dependence on temperature and require precision alignment. The last decade has seen a significant shift away from these in favor of arrays of digitally driven, inexpensive transducers, giving a new dynamic to the topic which we review herein

A blood atlas of COVID-19 defines hallmarks of disease severity and specificity.

Treatment of severe COVID-19 is currently limited by clinical heterogeneity and incomplete description of specific immune biomarkers. We present here a comprehensive multi-omic blood atlas for patients with varying COVID-19 severity in an integrated comparison with influenza and sepsis patients versus healthy volunteers. We identify immune signatures and correlates of host response. Hallmarks of disease severity involved cells, their inflammatory mediators and networks, including progenitor cells and specific myeloid and lymphocyte subsets, features of the immune repertoire, acute phase response, metabolism, and coagulation. Persisting immune activation involving AP-1/p38MAPK was a specific feature of COVID-19. The plasma proteome enabled sub-phenotyping into patient clusters, predictive of severity and outcome. Systems-based integrative analyses including tensor and matrix decomposition of all modalities revealed feature groupings linked with severity and specificity compared to influenza and sepsis. Our approach and blood atlas will support future drug development, clinical trial design, and personalized medicine approaches for COVID-19