Advanced Photon Source Upgrade Research Articles

Coupled bunch mode zero correction within the orbit feedback bandwidth

The fast orbit feedback (FOFB) bandwidth for Advanced photon source upgrade (APS-U) will be DC-1 kHz and the synchrotron frequency will be between 100-560 Hz. This frequency overlap places coupled bunch mode 0 (CBM0) induced horizontal orbit motion inside the orbit feedback bandwidth, potentially affecting our ability to achieve beam stability goals. Longitudinal feedback kicker is not strong enough to damp CBM0 oscillations. We developed new beam-based feedback method to suppress CBM0 oscillations with low level RF phase as actuator. It uses existent FOFB framework with no changes to the feedback algorithm. Effectiveness of this method is verified using present APS operations lattice where synchrotron frequency is outside orbit feedback bandwidth. In the present work, low alpha lattice is created to emulate APS-U setting where synchrotron frequency is inside the orbit feedback bandwidth. Experiments with this lattice successfully demonstrated CBM0 correction within orbit feedback bandwidth. Combined operation of orbit feedback and CBM0 correction is stable, and CBM0 oscillations are damped. We achieved better orbit motion suppression and corrector drive efforts are reduced as well.

Development of x-ray beam wavefront sensors for Advanced Photon Source upgrade.

Next-generation synchrotron radiation facilities, such as the Advanced Photon Source Upgrade (APS-U), bring significant advancements in scientific research capabilities, necessitating advanced diagnostic tools. Central to these diagnostics are x-ray wavefront sensors, crucial for preserving beam properties, including brightness, coherence, and stability. This paper presents two novel wavefront sensor prototypes developed at the APS using the coded-mask-based technique. The first is a compact design tailored for specific conditions and adaptability to diverse beamline configurations. The second, an adjustable zoom version, offers flexibility to accommodate a wide range of beam conditions. Both prototypes underwent rigorous testing at the APS 28-ID-B beamline and demonstrated their effectiveness in both absolute wavefront sensing and relative metrology modes. These results highlight their promise in beamline diagnostics, potentially enabling applications such as beamline auto-alignment and real-time wavefront manipulation.

Ultrasound pulse-echo measurements in a large-volume press at the High-Pressure Collaborative Access Team (HPCAT)

The large-volume press at beamline 16-BM-B, at the High-Pressure Collaborative Access Team (HPCAT) facility at the Advanced Photon Source (APS), Argonne National Laboratory, offers a comprehensive platform for in-situ characterization of materials' atomic structure and bulk properties under high pressure and/or high-temperature (HP-T) conditions. The beamline is equipped with a Paris-Edinburgh type press with in-situ X-ray, electrical, optical, and ultrasound probes. The ultrasound pulse-echo technique, in conjunction with other techniques, such as energy-dispersive X-ray diffraction, X-ray radiography, and thermal/electric measurements, provides relevant data on material properties, including elastic constants, equation of state, and phase transitions, at HP-T conditions. The beamline is currently undergoing a major redesign to coincide with the APS upgrade. Among other developments, the ultrasound measurements at the upgraded beamline will be optimized with the addition of rotational X-ray tomography, as well as new capabilities for online data analysis. These advancements, together with the improved beamline optics, will improve accuracy and significantly reduce the time needed for data collection, allowing for faster experiments and higher throughput. The presentation will provide an overview of beamline 16-BM-B with a specific focus on acoustic measurements using the ultrasound pulse-echo technique and relevant applications. The beamline's expanded capabilities and scientific examples will be presented.

Increasing capabilities at GM/CA@APS beamlines during the APS upgrade

Increasing capabilities at GM/CA@APS beamlines during the APS upgrade

New capabilities of the Structural Science Group beamlines before and after the APS upgrade

New capabilities of the Structural Science Group beamlines before and after the APS upgrade

The GM/CA@APS Structural Biology Facility upgrade plan and APS upgrade

The GM/CA@APS Structural Biology Facility upgrade plan and APS upgrade

Design, Fabrication, and Testing of a 1.9-m-Long, 16.5-mm Period NbTi Superconducting Undulator for the Advanced Photon Source Upgrade

Superconducting undulator (SCU) technology has been in use at the Advanced Photon Source since 2013. Due to the successful and reliable operation of the existing SCUs, the Advanced Photon Source upgrade project has decided to expand the use of NbTi-based SCUs. The first new magnets to be designed and fabricated are 1.9 m long with a period length of 16.5 mm. NbTi superconductor is used for coil winding and there are four separate coils wound on the mandrel to produce the main undulator field along with end compensation and distributed dipole compensation. The magnetic design, fabrication details, assembly, and testing are described in detail.

Coupled bunch mode zero correction using orbit measurements and rf system phase feedback

The target bandwidth of the Advanced Photon Source Upgrade (APS-U) fast orbit feedback (FOFB) is dc-1000 Hz where the synchrotron tune will be between 100 and 560 Hz. This overlap places coupled bunch mode 0 (CBM0) induced horizontal position offsets within the FOFB bandwidth range, affecting our ability to achieve APS-U goals for beam stability. In this article, we present a new feedback technique to damp CBM0 oscillations using the existent FOFB controller framework with no additional hardware and software requirements. Based on the theory of synchrotron oscillations, we developed a feedback algorithm that uses the beam horizontal position measurements at dispersive beam position monitors (BPM) as input and the low level rf (LLRF) phase as an actuator. We demonstrated via experiments in the present APS storage ring that this configuration can correct CBM0 oscillations, and also it can work simultaneously with orbit feedback used to damp ordinary betatron orbit. The simulation model for the proposed orbit to rf phase feedback system is implemented in matlab/simulink to guide us in the controller design. Simulation responses are in good agreement with measurements.

Overview of HPCAT and capabilities for studying minerals and various other materials at high-pressure conditions

High-Pressure Collaborative Access Team (HPCAT) is a synchrotron-based facility located at the Advanced Photon Source (APS). With four online experimental stations and various offline capabilities, HPCAT is focused on providing synchrotron x-ray capabilities for high pressure and temperature research and supporting a broad user community. Overall, the array of online/offline capabilities is described, including some of the recent developments for remote user support and the concomitant impact of the current pandemic. General overview of work done at HPCAT and with a focus on some of the minerals relevant work and supporting capabilities is also discussed. With the impending APS-Upgrade (APS-U), there is a considerable effort within HPCAT to improve and add capabilities. These are summarized briefly for each of the end-stations.

Capabilities and capacities of the NSLS-II beamlines AMX and FMX during the APS upgrade 'dark period'

Capabilities and capacities of the NSLS-II beamlines AMX and FMX during the APS upgrade 'dark period'

The APS upgrade: new opportunities for materials and applied science

The APS upgrade: new opportunities for materials and applied science

A Phase Shifter for Inline Undulators at the Advanced Photon Source Upgrade Project

A Phase Shifter for Inline Undulators at the Advanced Photon Source Upgrade Project

Swap-Out Safety Tracking for the Advanced Photon Source Upgrade

Swap-Out Safety Tracking for the Advanced Photon Source Upgrade

Simulations of Beam Strikes on Advanced Photon Source Upgrade Collimators using FLASH, MARS, and elegant

Simulations of Beam Strikes on Advanced Photon Source Upgrade Collimators using FLASH, MARS, and elegant

High Performance DAQ Infrastructure to Enable Machine Learning for the Advanced Photon Source Upgrade

High Performance DAQ Infrastructure to Enable Machine Learning for the Advanced Photon Source Upgrade

Evaluation of Pulsed Septum Leakage Fields and Compensation for the Advanced Photon Source Upgrade

Evaluation of Pulsed Septum Leakage Fields and Compensation for the Advanced Photon Source Upgrade

Design of the X-Ray Beam Size Monitor for the Advanced Photon Source Upgrade

Design of the X-Ray Beam Size Monitor for the Advanced Photon Source Upgrade

Design study of APS-U-type hybrid-MBA lattice for mid-energy DLSR

In recent years, a new generation of storage ring-based light sources, known as diffraction-limited storage rings (DLSRs), whose emittance approaches the diffraction limit for the range of X-ray wavelengths of interest to the scientific community, has garnered significant attention worldwide. Researchers have begun to design and build DLSRs. Among various DLSR proposals, the hybrid multibend achromat (H-MBA) lattice enables sextupole strengths to be maintained at a reasonable level when minimizing the emittance; hence, it has been adopted in many DLSR designs. Based on the H-7BA lattice, the design of the Advanced Photon Source Upgrade Project (APS-U) can effectively reduce emittance by replacing six quadrupoles with anti-bends. Herein, we discuss the feasibility of designing an APS-U-type H-MBA lattice for the Southern Advanced Photon Source, a mid-energy DLSR light source with ultralow emittance that has been proposed to be built adjacent to the China Spallation Neutron Source. Both linear and nonlinear dynamics are optimized to obtain a detailed design of this type of lattice. The emittance is minimized, while a sufficiently large dynamic aperture (DA) and momentum acceptance (MA) are maintained. A design comprising 36 APS-U type H-7BAs, with an energy of 3 GeV and a circumference of 972 m, is achieved. The horizontal natural emittance is 20 pm·rad, with a horizontal DA of 5.8 mm, a vertical DA of 4.5 mm, and an MA of 4%, as well as a long longitudinal damping time of 120 ms. Subsequently, a few modifications are performed based on the APS-U-type lattice to reduce the maximum value of damping time from 120 to 44 ms while maintaining other performance parameters at the same level.

Measuring vacuum component impedance for the Argonne Advanced Photon Source upgrade

The Advanced Photon Source plans to upgrade to a multibend achromat (MBA) lattice that will dramatically decrease the electron beam emittance, thereby enhancing the x-ray brightness by two to three orders of magnitude. Electron beam focusing in the MBA requires small-aperture vacuum components that must also have a small impedance so as to minimize rf-heating and collective instabilities. As part of this effort, this paper focuses on coupling impedance measurements and analysis of certain critical Advanced Photon Source Upgrade vacuum components. Impedance measurements of accelerator components have traditionally been done with the coaxial wire method, which is based on the fact that the Transverse Electro-Magnetic (TEM) mode of the coaxial cable can mimic the Coulomb field of a particle beam; however this measurement technique has various limitations. This paper describes our approach to measure the coupling impedance using a Goubau line (G-line), which is essentially a single wire transmission line designed to propagate Sommerfeld-like surface waves whose fundamental Transverse Magnetic (TM) mode mimics the Coulomb field of a relativistic particle beam. We describe in detail the measurement procedure that we have developed for the G-line, including the measurement setup and proper definition of a reference, measurement procedure and advantages, and our experience regarding how to reduce systematic experimental error that we learned over the course of the measurements. Starting with our initial suite of measurements and simulations designed to benchmark and validate the novel G-line based measurement technique, we present the measured results for several Advanced Photon Source Upgrade vacuum components, including those of two rf-gasket designs and the beam position monitor-bellows assembly.

A ray-tracing algorithm for ab initio calculation of thermal load in undulator-based synchrotron beamlines.

The OASYS suite and its powerful integration features are used to implement a ray-tracing algorithm to accurately calculate the thermal load in any component of an undulator-based synchrotron beamline. This is achieved by sampling and converting the SRW source of a given energy into a Shadow source and using the latter code to ray trace the full beamline. The accuracy of the algorithm is proved by reconstructing the full undulator radiation distribution through an aperture and comparing the result with direct calculaton of the total power usingSRW. The algorithm is particularly suited to analyze cases with complex beamline layouts and optical elements, such as crystals, multilayers, and compound refractive lenses. Examples of its use to calculate the power load on elements of two of the feature beamlines at the Advanced Photon Source Upgrade Project and a comparison of the results with analytical calculations arepresented.