We present a Secure EPICS PVAccess (SPVA) deployment framework developed at SLAC to enable authenticated, encrypted and authorized access to control systems from external scientific networks. In Phase 1, SPVA has been deployed to connect HPC clients and services on SLAC’s Scientific External Network to internal PVAccess gateways supporting production accelerators. SPVA enforces strong mutual authentication using Kerberos service principals, which establish the runtime identity of services and clients. These identities are used to request short-lived X.509 certificates from the SLAC-managed PVAccess Certificate Management Service (PVACMS). The certificates are used for TLS-secured PVAccess communication, ensuring cryptographic trust between peers. Authorization decisions are enforced through Access Security Files (ACFs) that define PVAccess security groups (ASGs) referencing User Access Groups (UAGs) and Host Access Groups (HAGs). These groups are centrally managed in LDAPS, allowing fine-grained control based on organizational roles and host policies. This framework provides secure, traceable access to EPICS PVs across administrative domains while maintaining compatibility with PVXS-based IOCs and tools. This abstract outlines the architectural design and operational lessons from the Phase 1 rollout, providing a model for deploying secure control system access in federated scientific computing environments.

The relationships of diffraction momentum coordinates with Cartesian position coordinates at User Facility beamlines with EPICS controls is discussed. The EPICS IOC computes relations between real space and reciprocal diffraction space motors for various four circle and six circle diffractometer geometries. Development on trajectory previews, collision detection, and on-board scan visualization is evaluated.

HEPS (High Energy Photon Source) will be the first high-energy (6 GeV) synchrotron radiation light source in China, which is mainly composed of accelerator, beamlines and end-stations. Phase I of the project includes 14 user beamlines and one test beamline. Construction of HEPS began in June 2019 and is scheduled for completion in late 2025. Meanwhile, beamlines have completed photon beam commissioning, marking HEPS' official transition to the joint-commissioning phase, starting from March 27th, 2025. The beamline controlled devices are mainly divided into two categories: one category is optical adjustment devices such as slits, K-B Mirrors, monochromators, etc.; the other category is optical diagnostic and detection devices such as XBPMs (X - ray Beam Position Monitors), fluorescence targets, detectors, etc. The beamline control system has been designed, based on the EPICS framework. Beamline network topology consists of three networks, namely the data network, control network, and equipment network. In order to enhance the software reusability and maintain version uniformity, package management technology is utilized to manage both application software and system software. Here, the design and construction of beamline control system are presented.

The Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory is a pioneering X-ray free-electron laser that provides researchers with the ability to investigate matter at atomic and molecular scales with unprecedented temporal and spatial resolution. Its applications span a wide range of scientific disciplines, including materials science, chemistry, biology, and physics. A vital aspect of conducting successful experiments at LCLS is the precise delivery of samples into the X-ray beam. Depending on the nature of the sample—whether liquid, gas, or solid—various delivery systems are employed to ensure accurate positioning, high repetition rates, and minimal sample waste. In this talk, I will present an overview of the control systems developed to support liquid sample delivery for the chemRIXS instrument. I will focus on two advanced systems that have significantly enhanced experimental capabilities. The first is a recirculating liquid sheet jet system that enables the generation of tunable liquid sheets with minimal sample volume, making it ideal for experiments with limited material availability. The second is a Droplet-on-Demand (DoD) robot designed for high-throughput pump–probe studies. This system allows precise sample placement, low sample consumption, and efficient mixing, which are essential for time-resolved measurements.

The LCLS-II optical delivery system supports multiple interaction points across multiple experiment hutches using only a handful of laser sources. This reduces financial burden and space usage at the cost of increased complexity for the optical laser systems. To ameliorate this complexity, each interaction point is supplied with a Modular Optical Delivery System (MODS) to inject, shape, and compress the beam before it is further conditioned for the experimental use. To meet operational demands, these MODS must be highly configurable, flexible, and robust while supporting 140+ control points in a dense enclosure. With control points spanning piezoelectric motors, optical imaging, digitizers, and more, the EPICS control system framework simplifies driver maintenance and allows growth of community-driven solutions. Each control point is accessible remotely via pyDM GUI which enables the operator to control these various alignment and diagnostic tools. Managing the deployment and operational stability of these modular systems is nontrivial and has presented several challenges in recent runs that inspired significant design changes for the future of the MODS. This talk takes a closer look at these operational challenges and the solutions we’ve implemented.

Beamline Experiment Control (BEC) has become the standardized high-level user interface for data-acquisition orchestration, adopted by nearly all beamlines. Built on a distributed server-client architecture, BEC seamlessly integrates with the underlying EPICS control system at Swiss Light Source (SLS), yet can also be used to steer and configure non-EPICS devices through Bluesky’s hardware abstraction layer “ophyd”. Beamlines are integrated through a plugin structure, which allows them to individually extend and adapt the system’s behavior: integrating new devices, customizing the user interface, rearranging visualization components, developing bespoke GUIs (BEC Widgets) or creating custom data analysis pipelines for on-the-fly execution. In addition, BEC enables beamlines to coordinate user access to the data acquisition through user access permissions, which can be fine-tuned either through manual interaction by the beamline scientist or automated updates from the digital user office. The long-term stability of the open-source project is ensured through automated testing (unit and end-to-end tests), semantic versioning, and automated deployment triggered on-demand by the beamline. BEC’s modularity, flexibility and its intuitive graphical user interfaces are streamlining data acquisition after the upgrade of the SLS to a fourth generation synchrotron.

The high X-ray flux at fourth generation synchrotron facilities enables high quality data acquisition with short detector integration times. Experiments whose durations were previously dominated by detector integration are thus increasingly dictated by the time required for motorized motion. In particular, experiments performed in a step-wise fashion — where motion is stopped during each integration — suffer from significant motion dead-time due to repeated acceleration/deceleration between each step. For this reason, interest in continuous scans — where detector integration occurs during motion — has grown within the synchrotron community. Precise synchronization is however required in order to ensure data acquisition at the desired positions. These synchronization demands can be particularly challenging in multi-dimensional scans involving multiple moving components. Here we present a hardware orchestrated, multi-dimensional, continuous scan implementation based on the IcePAP motion controller. Both motion control & detector triggering are orchestrated by the IcePAP hardware, resulting in high precision synchronization. Arbitrary motion trajectories — in up to 128 degrees of freedom — & trigger patterns can be implemented. Scan configuration & initiation is performed in software by the Sardana orchestration suite backed by the Tango control system. The implementation has been demonstrated to yield significant experimental time savings compared to equivalent step scans.

At LCLS, EPICS plays a central role in our controls architecture. IOCs are used to interface directly or indirectly with almost all experimental hardware supporting our heterogenous requirements. EPICS network protocols are used for making devices available over network, data acquistion, and security and safety of devices. These ultimately enable a rich environment of controls tools built around standardized communication protocols like Channel Access and pvAccess, such as alarm systems, software interlocks, and data analysis. This poster/oral presentation will detail how EPICS is used at LCLS and the tools built around or on top of it with specific examples and applications used on a day-to-day basis to accomplish basic and advanced needs of a complex controls system. This includes tools developed at LCLS or SLAC specifically to fulfill general needs that other users may be able to take advantage of. I will also talk about specific IOCs and Channel Access based tools I have made or worked on, and describe what EPICS currently does well along with its limitations.

For soft X-ray spectroscopy beamlines, delay line detectors are often the main system for detecting the photons from the sample and hence also a component determining the overall beamline performance as it might be a limiting factor of both measurement speed, noise, artifacts, and resolution. As such, and even more with larger micro channel plate driven delay line detectors, the signal readout must be fast and robust to minimize noise and artifacts while still accommodating even the flux from 4th generation synchrotrons. This paper studies the signal response of a delay line detector and how the ns current signal pulses can be filtered, amplified, and converted to voltage before the digitization. The digitizer is a 12 bit 2.5 GSPS 6 channel system, which is set up in a manner to minimize noise and enable post signal analysis integrated into the Sardana control system and live view. The early results indicate that many of the currently present image artifacts are, to a very high degree, suppressed due to analog signal treatment and proper triggering. The digitized signals are fitted using the python tool lmfit to different signal models, such as the exponentially modified Gaussian, to extract the peak of the main signal after identifying the common background response in all channels with the aim to even further improve the resolution of the detector. To optimize sampling, the system is also stress tested with regards to e.g. sampling length and out of range measurement.

X-ray absorption spectroscopy (XAS) is one of the techniques that require multiple beamline devices to operate in tight synchronization to maximize beam flux, focus, and reliable measurements. These devices, such as the undulator, monochromator, quarter-wave plate, and detectors, exhibit a variety of behaviors, phenomena, capabilities, and controller platforms, ranging from the photon source to the sample holder. First, this work aims to provide an overview of the existing methods, detailing the adopted synchronization definition, and then demonstrates top-notch commissioning results for critical on-the-fly synchrotron measurements – impacting significantly EMA (extreme conditions), QUATI (quick-EXAFS) and SABIA (XMCD) Sirius beamlines. Additionally, the paper highlights the architecture's adaptability, enabling integration across a range of devices while maintaining custom, precise temporal and energy calibration, ensuring short scan duration and minimizing sample damage.

The newly enhanced LCLS-II X-ray laser at SLAC National Accelerator Laboratory represents a major advancement in X-ray science, providing unprecedented capabilities for probing ultrafast dynamics in chemistry, materials science, biology, and beyond. Among the new beamlines, the Resonant Inelastic X-ray Scattering (RIX) beamline leverages the high repetition rate of LCLS-II to investigate the energy distribution and evolution of occupied and unoccupied molecular orbitals in complex and catalytic systems, particularly in liquid environments. This beamline features two dedicated endstations—qRIXS (upstream) and chemRIXS (downstream)—each optimized for distinct scientific goals. This talk will detail the design and implementation of the experimental controls and data systems that unify beamline hardware and instrument automation. Additionally, this talk will discuss the challenges of synchronizing operations across two endstations on a single beamline for time-resolved spectroscopy under demanding experimental conditions.