PERCIVAL (“Pixelated Energy Resolving CMOS Imager, Versatile And Large”) is a monolithic active pixel sensor (MAPS) based on CMOS technology. Is being developed by DESY, RAL/STFC, Elettra, DLS, and PAL to address the various requirements of detectors at synchrotron radiation sources and Free Electron Lasers (FELs) in the soft X-ray regime. These requirements include high frame rates and FELs base-rate compatibility, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency (QE), and (multi-)megapixel arrangements with good spatial resolution. Small-scale back-side-illuminated (BSI) prototype systems are undergoing detailed testing with X-rays and optical photons, in preparation of submission of a larger sensor. A first BSI processed prototype was tested in 2014 and a preliminary result—first detection of 350eV photons with some pixel types of PERCIVAL—reported at this meeting a year ago. Subsequent more detailed analysis revealed a very low QE and pointed to contamination as a possible cause. In the past year, BSI-processed chips on two more wafers were tested and their response to soft X-ray evaluated. We report here the improved charge collection efficiency (CCE) of different PERCIVAL pixel types for 400eV soft X-rays together with Airy patterns, response to a flat field, and noise performance for such a newly BSI-processed prototype sensor.

Considerable interest has been manifested for the use of high-brilliance X-ray synchrotron sources and X-ray Free-Electron Lasers for the investigation of samples.

The PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile and Large") is a collaboration of DESY, RAL/STFC, ELETTRA, and DLS to develop a monolithic active pixel sensor (MAPS) to provide a suitable detector for photon science for the photon energy regime between 250 eV and 1 keV. An important performance parameter is the spatial resolution which can be inferred from the Modulation Transfer Function (MTF). The MTF measures in optical systems the relative contrast of a pattern in function of the spatial frequency. With a back-thinned and back- illuminated PERCIVAL prototype chip, dedicated MTF evaluation data were taken at Elettra's TwinMic Beamline in March 2014 at a photon energy of 535 eV. We will present our MTF derivation approaches together with MTF results for 3 pixel types of the irradiated test sensor.

Many synchrotron beamlines offer some form of continuous scanning for either energy scanning or sample mapping. However, this is normally done on an ad-hoc beamline by beamline basis. Diamond has recently embarked on an ambitious project to define how to implement continuous scanning as the standard way of doing virtually all mapping tasks on beamlines. The project is split into four main areas: 1) User interfaces to describe the mapping process in a scientifically relevant way, generating a scan description that can be used later; 2) The physical process of scanning and coordinating hardware motion and detector data capture across the beamline; 3) Capture of the detector data and all the associated meta-data to disk, deciding and describing the layout of the file (or files) for the main use cases; 4) Display and analysis of live data and display of processed data. In order to achieve this common approach across beamlines, the standard software used throughout the facility (Delta Tau motor controllers, EPICS, GDA and DAWN), has been built on.

The PERCIVAL soft-X-ray (250 eV 1 keV) image detector project is a collaboration between DESY, STFC, Elettra Sincrotrone Trieste and Diamond Light Source. The objective of the project is to develop a back-thinned CMOS detector which outperforms present soft-X ray image detector technology, in terms of sensor size, noise, dynamic range and frame rate. The size of this 13M pixel imager associated with its 120 frames per second frame rate impose very challenging requirements to the Data Acquisition Backend of the system. A DAQ backend system architecture, using a commercial deep-buffer switch to rearrange image data streams coming from different regions of the sensor via several 10Gbps Ethernet links has been proposed to reassemble image frames. Real-time data processing is to be performed on multiple, parallel commodity compute nodes. This contribution to the conference reports on benchmarking tests performed as a feasibility study, and presents the resulting recommendations for the system architecture of the PERCIVAL detector DAQ backend. The feasibility study covered three key issues: Reliably moving data in UDP packets from multiple 10Gbps Ethernet links from the DAQ front-end electronics to commodity compute nodes; Real-time processing on the compute nodes; and finally streaming data to a central parallel storage system.

Free-Electron Lasers and Synchrotrons are rapidly increasing in brilliance. This has led a requirement of large dynamic range and high frame rate sensors that is now being fulfilled by the PERCVIAL CMOS imager for direct X-ray detection developed at Rutherford Appleton Laboratory. Utilising a lateral overflow pixel and back-side illumination, PERCIVAL simultaneously achieves low-noise single-photon detection and high full well up to 10(7) e(-), all while maintaining a frame rate of 120Hz. PERCIVAL is currently in test structure stage, and will be produced in 2 Mpixel and 13 Mpixel "waferscale" variants in 2015.

Over the last decade, synchrotron radiation sources have seen a significant increase in brilliance, and the advent of free electron lasers has made entire new research fields accessible to investigations with X-rays. These advances in light source capabilities have resulted not only in a host of scientific advances and discoveries, but also in a need for a new generation of X-ray imaging detectors that can match the sources' capabilities in terms of frame rate and image dynamic range while recording image information with fine granularity over a large – preferably uninterrupted – (multi)megapixel area with single-photon sensitivity. Developing such next-generation imagers is both costly and time-consuming, and the requirements at many photon science facilities are similar enough to invite a collaborative effort. The Percival (“Pixellated Energy Resolving CMOS Imager, Versatile And Large”) imager is being developed by a collaboration of DESY, Rutherford Appleton Laboratory (RAL), Elettra, and Diamond Light Source (DLS) to answer this need for the soft X-ray regime.

An increasing number of area detectors, in use at Diamond Light Source, produce high rates of data. In order to capture, store and process this data High Performance Computing (HPC) systems have been implemented. This paper will present the architecture and usage for handling high rate data: detector data capture, large volume storage and parallel processing.The EPICS areaDetector framework has been adopted to abstract the detectors for common tasks including live processing, file format and storage. The chosen data format is HDF5 which provides multidimensional data storage and NeXuS compatibility.The storage system and related computing infrastructure include: a centralised Lustre based parallel file system, a dedicated network and a HPC cluster. A well defined roadmap is in place for the evolution of this to meet demand as the requirements and technology advances.For processing the science data the HPC cluster allow efficient parallel computing, on a mixture of x86 and GPU processing units. The nature of the Lustre storage system in combination with the parallel HDF5 library allow efficient disk I/O during computation jobs. Software developments, which include utilising optimised parallel file reading for a variety of post processing techniques, are being developed in collaboration as part of the Pan-Data EU Project (www.pan-data.eu). These are particularly applicable to tomographic reconstruction and processing of non crystalline diffraction data.

The software for the Diamond Light Source beamlines[1] is based on two complementary software frameworks: low level control is provided by the Experimental Physics and Industrial Control System (EPICS) framework[2][3] and the high level user interface is provided by the Java based Generic Data Acquisition or GDA[4][5]. EPICS provides a widely used, robust, generic interface across a wide range of hardware where the user interfaces are focused on serving the needs of engineers and beamline scientists to obtain detailed low level views of all aspects of the beamline control systems. The GDA system provides a high-level system that combines an understanding of scientific concepts, such as reciprocal lattice coordinates, a flexible python syntax scripting interface for the scientific user to control their data acquisition, and graphical user interfaces where necessary. This paper describes the beamline software architecture in more detail, highlighting how these complementary frameworks provide a flexible system that can accommodate a wide range of requirements.

Diamond is a new 3rd generation synchrotron light source currently being commissioned in the UK. The control system for Diamond is a site-wide monitoring and control system for the accelerators, beamlines and conventional facilities. This paper presents the design and implementation of the Diamond control system, which is based on the EPICS control system toolkit. It describes the detailed choice of hardware and software, the solutions realised for interfacing and control of the major technical systems of Diamond, and progress on installation and commissioning.