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With swap-out injection and a third-harmonic bunch lengthening cavity, time domain diagnostics will be beneficial tools in for optimisation of the Advanced Photon Source Upgrade electron storage ring. In the present work, we present plans for time-domain X-ray and visible photon diagnostics for the Advanced Photon Source Upgrade. Particular emphasis is given to implementation of visible light streak cameras and X-ray bunch purity monitors as time domain photon diagnostics., Proceedings of the 10th International Beam Instrumentation Conference, IBIC2021, Pohang, Rep. of Korea

A beam size monitor provides an intuitive display of the status of the beam profile and motion in an accelerator. In the present work, we outline the design of the X-ray electron beam size monitor for the Advanced Photon Source Upgrade. Components and anticipated performance characteristics of the beam size monitor are outlined., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

To best leverage the orders of magnitude average brightness increase of multi-bend achromat synchrotron radiation storage rings, ambitious beam stability requirements are imposed. One system that will be employed at the Advanced Photon Source Upgrade in support of photon beam stability will be X-ray beam position monitors. In the present work, electrical characterisation of several types of photodiodes are evaluated for potential use in X-ray beam position monitors., Proceedings of the 9th International Beam Instrumentation Conference, IBIC2020, Santos, Brazil

Relativistic electron beams in storage rings radiate a significant fraction of beam energy per turn. As demonstrated in previous experiments, with the radiofrequency accelerating structures off, the turn-by-turn time of arrival of the electron bunch can be observed from the synchrotron radiation that it produces using a streak camera. In the present work, we present measurements of the energy loss per turn of an initially short electron bunch (~1 ps RMS) from a photocathode electron gun in the Advanced Photon Source Particle Accumulator Ring (375 MeV, 10² ns revolution period). With the streak camera synchroscan locked to the twelfth harmonic of the revolution frequency (117.3 MHz), we observe an injection transient in the horizontal direction., Proceedings of the 9th International Beam Instrumentation Conference, IBIC2020, Santos, Brazil

Confirmation of pm rad scale emittances from the Advanced Photon Source Upgrade electron storage ring necessitates direct measurement of the electron beam size. In the present work, we motivate design choices for the X-ray beam size monitor shielding enclosure for the Advanced Photon Source Upgrade. Particular emphasis is given to outlining design choices from the perspectives of safety, overall project construction schedule and eventual beamline operations., Proceedings of the 9th International Beam Instrumentation Conference, IBIC2020, Santos, Brazil

Cameras can be a very useful accelerator diagnostic, particularly because an image of the beam distribution can be quickly interpreted by human operators, and increasingly can serve as an input to machine learning algorithms. We present an implementation of digital cameras for triggered photon diagnostics at the Advanced Photon Source using the areaDetector framework in the Experimental Physics and Industrial Controls System. Beam size measurements from the synchrotron light monitors in the Particle Accumulator Ring using the new architecture are presented., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

A particular challenge for diagnostics in diffraction limited storage ring light sources is the measurement of electron beam transverse emittances. In the present work, we present measurements and simulations of vertical electron beam emittance using high harmonics from an electromagnetic undulator in the present Advanced Photon Source storage ring. Based on these results, using simulation we motivate an undulator-based horizontal and vertical transverse emittance monitor for diffraction limited storage rings, using the Advanced Photon Source Upgrade as an example., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

Next-generation, high-performance storage ring light sources based on multibend achromat optics will require on-axis injection because of the extremely small dynamic aperture. Injectors will need to supply full-current bunch replacement in the ring with high single-bunch charge for swap-out. For upgrades of existing light sources, such as the Advanced Photon Source Upgrade (APS-U), it is economical to retain the existing injector infrastructure and make appropriate improvements. The challenges to these improvements include achieving high single-bunch charge in the presence of instabilities, beam loading, charge stability and reliability. In this paper, we discuss the rationale for the injector upgrades chosen for APS-U, as well as backup and potential alternate schemes. To date, we have achieved single-bunch charge from the injectors that doubles the original design value, and have a goal to achieve about three times the original design value., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

In order to maximise the injection efficiency from the booster synchrotron into the proposed Advanced Photon Source Upgrade storage ring, beam-based optimisation of the booster electron optical lattice is anticipated. In the present work, we present non-destructive beam size and emittance measurements using the booster synchrotron light monitor and destructive quadrupole scan emittance measurements in the booster to storage ring transport line. Destructive measurements are performed with a 0.1 mm thickness Cerium-doped Yttrium Aluminium Garnet screen. In order to characterise performance, both the beam energy at extraction (5, 6 and 7 GeV) and the bunch charge are varied., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

A fast photodetector is used to monitor the bunch duration in the Advanced Photon Source (APS) Particle Accumulator Ring (PAR). The Bunch Duration Monitor (BDM) diagnostic provides an accurate measure of the PAR bunch length. PAR BDM data show good agreement with streak camera measurements. The BDM is based on the metal-semiconductor-metal (MSM) photodetector Hamamatsu G4176-03 MSM with specified rise and fall times of 30 ps. The BDM has sufficient frequency response to resolve the PAR bunch near extraction where, under low-charge conditions, minimum rms pulse durations of 200-300 ps are observed. Beam from the PAR is injected into the Booster; for efficient capture, injected rms bunch duration from the PAR must be less than 600 ps. The MSM detector exhibits a ringing response to fast input signals. To overcome this, the BDM output is de-convolved with the impulse response function of the detector-amplifier circuit. Turn-by-turn bunch duration data is presented versus charge and time in the PAR cycle. Charge calibration is used to determine fit parameters for bunch duration measurements in peak-detection mode. Observations relevant to APS Upgrade high-charge studies are presented., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The Advanced Photon Source (APS) is currently in the preliminary design phase for a multi-bend acromat (MBA) lattice upgrade. Beam stability is critical where the requirements are driven from the beam size which is expected to approach 4 microns vertically at the insertion device (ID) source points. AC rms beam stability requirements are defined as 10 % the minimum source size at the ID in the band 0.01-1000 Hz. The vertical plane stability goal is the most ambitious requiring a stability of 400 nm at the ID source point. In addition, long term drift defined as motion over a seven day timescale can be no more than 1 micron. In order to achieve these demanding beam stability requirements, a suite of beam diagnostics will be required including rf BPMs, X-ray BPMs, a mechanical motion measurement system, beam size monitors and a real time orbit feedback system. In addition, a tune measurement system, transverse multi-bunch feedback system and current monitors are planned for the upgrade. We report on the beam diagnostics design and APS storage ring R&D results used to inform the design., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The Advanced Photon Source (APS) upgrade from double-bend achromats (DBA) to multi-bend achromats (MBA) lattice has increased the need for reliable diagnos-tic systems. This upgrade will decrease the size of the photon beam drastically and beam current will be in-creased from 100 mA to 200 mA. The small beam and intense heat loads provided by the upgraded APS requires unique and innovative approaches to beam position monitoring. To meet the need for a reliable diagnostic system for the APS upgrade, the next generation X-ray Beam Position Monitoring System (XBPM) is required which includes the first XBPM (XBPM1), the Intensity Monitor (IM1) and the second XBPM (XBPM2). This paper presents progress and status of the current configu-ration of the XBPM system especially the development work involving the IM1 and XBPM2. The R&D work to develop an alternative XBPM1 using the Compton scattering principle is also presented., Proceedings of the Mechanical Eng.~Design of Synchrotron Radiation Equipment and Instrumentation, MEDSI2018, Paris, France

Accurate and stable x-ray beam position monitors (XBPMs) are key elements in obtaining the desired user beam stability in the Advanced Photon Source (APS). Currently, the APS is upgrading its facility to increase productivity and to provide far more highly coherent and brilliant hard x-rays to beamline experiments with a new storage ring magnet lattice based on a multi-bend achromat (MBA) lattice. To improve the beam stability, one of the proposed beam diagnostics is the grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) for high heat load (HHL) front ends (FEs) at the APS. In this paper, final design of the GRID-XBPM and the high-power beam test results at beamline 27-ID-FE will be addressed., Proceedings of the 9th Edition of the Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation Conference, MEDSI2016, Barcelona, Spain

The Advanced Photon Source is developing its next major upgrade (APS-U) based on the multi-bend achromat lattice. Improved beam stability is critical for this upgrade and will require keeping short-time beam angle change below 0.25 μrad and long-term angle drift below 0.5 micro-radian. A reliable white x-ray beam diagnostic system in the front end is a key part of the planned beam stabilization system for the APS-U. This system includes an x-ray beam position monitor (XBPM) based on x-ray fluorescence (XRF) from two specially designed GlidCop A-15 absorbers, a second XBPM using XRF photons from the Exit Mask, and two white beam intensity monitors using XRF from the photon shutter and Compton-scattered photons from the front end beryllium window. We present orbit stability data for the first XBPM used in the feedback control during user operations, as well as test data from the second XBPM and the intensity monitors. The data demonstrated that the XBPM system meets the APS-U beam stability requirements., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

The Advanced Photon Source (APS) is developing the design of a multi-bend achromat (MBA) lattice based storage ring as the next major upgrade, featuring a 20-fold reduction in emittance. Combining the reduction of beta functions, the electron beam sizes at bend magnet sources may be reduced to reach 5 - 10 μm for 10% vertical coupling. The x-ray pinhole camera currently used for beam size monitoring will not be adequate for the new task. By increasing the operating photon energy to 120 keV or higher, the pinhole camera's resolution is expected to reach below 4 μm. The peak height of the pinhole image will be used to monitor relative changes of the beam sizes and enable the feedback control of the emittance. We present the computer simulation and the design of a prototype beam size monitor for the APS storage ring., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

The new orbit feedback system required for the APS multi-bend acromat (MBA) ring must meet challenging beam stability requirements. The AC stability requirement is to correct rms beam motion to 10 \% the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. In addition long term drift over a period of 7 days is required to be 1 micron or less at insertion device BPMs and 2 microns for arc bpms. We present test results of the MBA prototype orbit feedback controller (FBC) in the APS storage ring. In this test, four insertion device BPMs were configured to send data to the FBC for processing into four fast corrector setpoints. The configuration of four bpms and four fast correctors creates a 4-bump and the configuration of fast correctors is similar to what will be implemented in the MBA ring. We report on performance benefits of increasing the sampling rate by a factor of 15 to 22.6 kHz over the existing APS orbit feedback system, limitations due to existing storage ring hardware and MBA orbit feedback design., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

The Advanced Photon Source (APS) is currently in the preliminary design phase for the multi -bend achromat (MBA) lattice upgrade. Beam stability is critical for the MBA and will require long term drift defined as beam motion over a seven-day timescale to be no more than 1 micron at the insertion device locations and beam angle change no more than 0.5 micro-radian. Mechanical stability of beam position monitor (BPM) pickup electrodes mounted on insertion device vacuum chambers place a fundamental limitation on long-term beam stability for insertion device beamlines. We present the design and implementation of using prototype mechanical motion system (MMS) instrumentation for quantifying this type of motion specifically in the APS accelerator tunnel and experiment hall floor under normal operating conditions. The MMS presently provides critical position information on the vacuum chamber and BPM support systems. Initial results of the R&D prototype systems have demonstrated that the chamber movements far exceed the long-term drift tolerance specified for the APS Upgrade MBA storage ring., Proceedings of the 5th Int. Beam Instrumentation Conf., IBIC2016, Barcelona, Spain

Particle loss from Touschek scattering is one of the most significant issues faced by present and future synchrotron light source storage rings. For example, the predicted, Touschek-dominated beam lifetime for the Advanced Photon Source (APS) Upgrade lattice in 48-bunch, 200-mA timing mode is only ~2 h. In order to understand the reliability of the predicted lifetime, a series of measurements with various beam parameters was performed on the present APS storage ring. This paper first describes the entire process of beam lifetime measurement, then compares measured lifetime with the calculated one by applying the measured beam parameters. The results show very good agreement., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

Beam diagnostics required for the APS MBA are driven by ambitious beam stability requirements. The major AC stability challenge is to correct rms beam motion to 10% the rms beam size at the insertion device source points from 0.01 to 1000 Hz. The vertical plane represents the biggest challenge for AC stability which is required to be 400 nm rms for a 4 micron vertical beam size. Long term drift over a period of 7 days is required to be 1 micron or less. Major diagnostics R&D components are improved rf beam position processing using commercially available fpga based bpm processors, new XRay beam position monitors sensitive only to hard X-rays, mechanical motion sensing and remediation to detect and correct long term drift and a new feedback system featuring a tenfold increase in sampling rate and a several-fold increase in the number of fast correctors and bpms. Feedback system development represents a major effort and we are pursuing development of a novel algorithm that integrates orbit correction for both slow and fast correctors down to DC simultaneously. Finally a new data acquisition system (DAQ) is being developed to acquire streaming data from all diagnostics., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

Very short Touschek lifetime becomes a common issue for next-generation ultra-low emittance storage ring light sources. In order to reach a longer beam lifetime, such a machine often requires operating with a vertical-to-horizontal emittance ratio close to an unity, i.e. a ‘‘round beam''. In tests at the APS storage ring, we determined how a round beam can be reached experimentally. Some general issues, such as beam injection, optics measurement and corrections, and orbit correction have been tested also. To demonstrate that a round beam was achieved, the beam size ratio is calibrated using beam lifetime measurement., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The Advanced Photon Source (APS) is currently in the conceptual design phase for the MBA lattice upgrade. In order to achieve long-term beam stability goals, a Mechanical Motion System (MMS) has been designed to monitor critical in-tunnel beam position monitoring devices. The mechanical motion generated from changes in chamber cooling water temperature, tunnel air temperature, beam current and undulator gap positon causes erroneous changes in beam position measurements causing drift in the X-ray beam position. The MMS has been prototyped and presently provides critical information on the vacuum chamber and BPM support systems. We report on first results of the prototype system installed in the APS storage ring., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The proposed Advanced Photon Source (APS) Upgrade will bring storage-ring beam sizes down to several micrometers and require x-ray beam directional stability in 100 nrad range for undulator power exceeding 16 kW. The next generation x-ray beam position monitors (XBPMs) are designed to meet these requirements. We present first commissioning data on the recently installed grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) based on Cu K-edge x-ray fluorescence from limiting absorbers of the front end for two inline undulators. It demonstrated a 50-fold improvement for signal-to-background ratio over existing photoemission-based XBPMs. Techniques for calibrating the XBPMs will be discussed. We will also present a new XBPM design based Compton scattering from diamond blades. This XBPM is designed for less powerful undulators such as the APS canted-undulator beamlines where each undulator generates < 10 kW of beam power. We will discuss the thermal design of the blade, the optics design of the detector assembly, and computer simulations of expected response to the x-ray beam. Test data of the prototype may be presented if available., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA