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An Accelerator Research facility is a unique science and engineering challenge in that the requirements for developing a robust, optimized science facility are limited by engineering and cost limitations. Each facility is planned to achieve some science goal within a given schedule and budget and is then expected to operate for three decades. In three decades, the mechanical systems and the industrial IO to control them is not likely to change. In that same time, electronics will go through some 4 generations of change. The software that integrates the systems and provides tools for operations, automation, data analysis and machine studies will have many new standards. To help understand the process of designing and planning such a facility, we explain the specifications and requirements for the Electron Ion Collider (EIC) from both a physics and engineering perspective., Proceedings of the 5th North American Particle Accelerator Conference, NAPAC2022, Albuquerque, NM, USA

We discuss impedance calculations and related heating issues of the titanium-coated NSLS-II kicker ceramic chambers, with the titanium coating thickness estimated from in situ measurements of the end-to-end resistance of each chamber. Power densities are calculated on the titanium coating to allow for thermal analysis with the code ANSYS and comparison with heating measurements. The impedance analysis is performed using a realistic model of the ceramic complex permittivity, and special consideration is given to the impedance calculation in the limit of zero titanium coating thickness., Proceedings of the 5th North American Particle Accelerator Conference, NAPAC2022, Albuquerque, NM, USA

The Electron-Ion Collider (EIC), to be built at Brookhaven National Laboratory (BNL), is designed to provide a high electron-proton luminosity of 10³⁴ cm⁻² s⁻¹. One of the challenging tasks for the Electron Storage Ring (ESR) is to operate at an average beam current of 2.5 A within 1160 bunches with a ~ 7 mm bunch length. The Hadron Storage Ring (HSR) will accumulate an average current of 0.69 A within 290 bunches with a 60 mm bunch length. Both rings require the impedance budget simulations. The intense e-beam in the ESR can lead to the overheating of vacuum chamber components due to localized metallic losses. This paper focuses on the beam-induced heating analysis of the ESR vacuum components including bellows, gate-valve, and BPM. To perform thermal analysis, the resistive loss on individual components is calculated with CST and then fed to ANSYS to determine the temperature distribution on the vacuum components. Preliminary results suggest that active water cooling will be required for most of the ESR vacuum components. Similar approach is applied to the HSR vacuum components. The thermal analysis of the HSR stripline injection kicker is presented., Proceedings of the 5th North American Particle Accelerator Conference, NAPAC2022, Albuquerque, NM, USA

The Electron Ion Collider aims to produce luminosities of 10³⁴ cm⁻²s⁻¹ . The machine will operate over a broad range of collision energies with highly polarized beams. The coexistence of highly radiative electrons and nonradiative ions produce a host of unique effects. Strong hadron cooling will be employed for the final factor of 3 luminosity boost., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Electron-Ion Collider (EIC) is being designed for construction at Brookhaven National Laboratory. Activities have been focused on beam-beam simulations, polarization studies, and beam dynamics, as well as on maturing the layout and lattice design of the constituent accelerators and the interaction region. The latest design advances will be presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The design of the electron-ion collider EIC to be constructed at Brookhaven National Laboratory has been continuously evolving towards a realistic and robust design that meets all the requirements set forth by the nuclear physics community in the White Paper. Over the past year activities have been focused on maturing the design, and on developing alternatives to mitigate risk. These include improvements of the interaction region design as well as modifications of the hadron ring vacuum system to accommodate the high average and peak beam currents. Beam dynamics studies have been performed to determine and optimize the dynamic aperture in the two collider rings and the beam-beam performance. We will present the EIC design with a focus on recent developments., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

This paper presents an overview of the Interaction Region (IR) design for the planned Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The IR is designed to meet the requirements of the nuclear physics community *. The IR design features a ±4.5 m free space for the detector; a forward spectrometer magnet is used for the detection of hadrons scattered under small angles. The hadrons are separated from the neutrons allowing detection of neutrons up to ±4 mrad. On the rear side, the electrons are separated from photons using a weak dipole magnet for the luminosity monitor and to detect scattered electrons (e-tagger). To avoid synchrotron radiation backgrounds in the detector no strong electron bending magnet is placed within 40 m upstream of the IP. The magnet apertures on the rear side are large enough to allow synchrotron radiation to pass through the magnets. The beam pipe has been optimized to reduce the impedance; the total power loss in the central vacuum chamber is expected to be less than 90 W. To reduce risk and cost the IR is designed to employ standard NbTi superconducting magnets, which are described in a separate paper., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

During the estimates of impedance budget for the Electron Storage Ring (ESR) of Electron-Ion Collider (EIC), various codes, including GdfidL, CST and ECHO3D, have been used to calculate the short-range wake-fields due to the vacuum components. The ECHO 3D code demonstrates more reliable results for the tapered type of structures rather than the GdfidL code, where the stepsize needs to be dramatically decreased to achieve a high-performance calculation. Impedance of the following components are discussed and compared in details: Interaction Region (IR) chamber, bellows, and synchrotron radiation mask (flange absorber)., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

A new high-luminosity Electron Ion Collider (EIC) is being developed at Brookhaven National Laboratory (BNL). The conceptual design [1] has recently been completed. The EIC will be realized in the existing RHIC facility. In addition to improving the existing hadron storage ring instrumentation, new electron accelerators that include a 350 keV gun, 400 MeV Linac, a rapid-cycling synchrotron, an electron storage ring, and a strong hadron cooling facility will all have new instrumentation systems. An overview of the conceptual design of the beam instrumentation will be presented., Proceedings of the 10th International Beam Instrumentation Conference, IBIC2021, Pohang, Rep. of Korea

The head-tail instability caused by the beam interaction with short-range wakefields is a major limitation for the single-bunch beam intensity in circular accelerators. The combined effect of the transverse feedback systems and chromaticity suppressing the instability is discussed. Theoretical and experimental studies of the head-tail instability and methods of its mitigation are reviewed. Results of experimental studies of the transverse mode coupling carried out at NSLS-II are compared with the theoretical model and numerical simulations., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

A new high-luminosity Electron-Ion Collider (EIC) is being designed at Brookhaven National Laboratory (BNL). Stable operation of the electron beam at an average current of 2.5A within 1100 bunches with a 7mm bunch length is one of the challenging tasks in achieving an electron-proton luminosity of 1033-1034 cm⁻² ses⁻¹ range. Beam induced heating, short-range and long-range wakefield analysis is discussed for some of the vacuum components of the electron storage ring (ESR), the hadron storage ring (HSR), and the rapid cycling synchrotron (RCS) and as well as the impact of the collective effects on the beam stability., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The horizontal/vertical emittances, the bunch length, and the energy spread increase have been studied in the NSLS-II as a function of a single bunch current. The monotonic growth of the horizontal emittance dependence and the energy spread dependence on the single bunch current below the microwave instability threshold can be explained by the Intrabeam Scattering Effect (IBS). The IBS effect results in an increase in the bunch length and the microwave instability thresholds. It was observed experimentally by varying the vertical emittance. To compare with experimental data, particle tracking simulations have been performed with the ELEGANT code including both IBS and the total longitudinal wakefield calculated from the 3D electromagnetic code GdfidL. The same particle tracking simulations have also been applied for the APS-U project, where IBS is predicted to produce only a marginal effect., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The interaction region chamber has a complex geometry at the crossing location of electron and proton beam pipes. In the direction of the electron beam, the pipe is designed in a way to avoid joints with cavity characteristics. The horizontal slot on the upstream side and the tapered transition on the downstream side are applied to minimize the IR chamber contribution to the total impedance of the electron ring and to avoid generating Higher Order Modes and heating-related issues. The synchrotron radiation mask is included to protect the IR chamber from synchrotron radiation without significant aperture reduction. In the direction of the proton beam, the main area for optimization is the transition area right after the detector., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

This paper is dedicated to the analysis of our recent experience from ramp-up of operating current at NSLS-II from 25 mA at the end of commissioning in 2014 to 475 mA achieved in studies today. To approach the design level of the ring intensity we had to solve major problems in overheating of the chamber components. Since the beginning of the NSLS-II commissioning, the temperature of the vacuum components has been monitored by the Resistance Temperature Detectors located predominantly outside of the vacuum chamber and attached to the chamber body. A couple of vacuum components were designed with the possibility for internal temperature measurements under the vacuum as diagnostic assemblies. Temperature map helps us to control overheating of the vacuum components around the ring especially during the current ramp-up. The average current of 475mA has been achieved with two main 500MHz RF cavities and w/o any harmonic cavities. In this paper we discuss the heating results for a 15ps bunch length (at low current) of the following vacuum components: Large Aperture BPM, Small Aperture BPM, Bellows, Flanges, Ceramics Chambers and Stripline Kickers., Proceedings of the North American Particle Accelerator Conference, NAPAC2019, Lansing, MI, USA

The Electron-Ion Collider (EIC) is being envisioned as the next facility to be constructed by the DOE Nuclear Physics program. Brookhaven National Laboratory is proposing eRHIC, a facility based on the existing RHIC complex as a cost effective realization of the EIC project with a peak luminosity of 10³⁴ cm⁻² sec⁻¹. An electron storage ring with an energy range from 5 to 18 GeV will be added in the existing RHIC tunnel. A spin-transparent rapid-cycling synchrotron (RCS) will serve as a full-energy polarized electron injector. Recent design improvements include reduction of the IR magnet strengths to avoid the necessity for Nb₃Sn magnets, and a novel hadron injection scheme to maximize the integrated luminosity. We will provide an overview of this proposed project and present the current design status., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R, Proceedings of the North American Particle Accelerator Conference, NAPAC2019, Lansing, MI, USA

Interaction of a particle beam with the vacuum chamber impedance is one of the main effects limiting the beam intensity in accelerators. Minimization of the impedance is an essential part of the vacuum chamber design for any new accelerator project. The impedance can be estimated experimentally by measuring beam dynamics effects caused by the beam-impedance interaction. Experience obtained at many accelerator facilities shows the beam-based measurements are often different from the pre-computed impedance budgets, the discrepancy of a factor of two or even more is not unusual. The measurements of broadband longitudinal impedance carried out at NSLS-II are discussed in comparison with the numerically simulated impedance budget., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The future electron-ion collider (EIC) aims at an electron-proton luminosity of 10³³ to 10³⁴ cm⁻² sec⁻¹ and a center-of-mass energy range from 20 to 140 GeV. The eRHIC design has been continuously evolving over a couple of years and has reached a considerable level of maturity. The concept is generally conservative with very few risk items which are mitigated in various ways., Proceedings of the North American Particle Accelerator Conference, NAPAC2019, Lansing, MI, USA

The NSLS-II storage ring uses the standard four bump injection scheme to inject beam off axis. BESSY and MAX IV are now using a pulsed multipole magnet as an injection kicker. The injected beam sees a field off axis for injection while the stored beam experiences no field on the magnet axis. The principle advantage of using a pulsed multipole for injection is that the stored beam motion is greatly reduced since the field on axis is negligible. The number of pulsed magnets is reduced from five in the nominal scheme (septum and four bumps) to two or three thereby reducing the possible failure modes. This also eliminates the need to precisely match the pulse shapes of four dipole magnets to achieve minimal stored beam motion outside of the bump. In this paper we discuss two schemes of injecting into the NSLS-II using a pulsed multipole magnet. The first scheme uses a single pulsed multipole located in one cell downstream of the injection septum as the injection kicker. The second scheme uses two pulsed multipoles in the injection straight to perform the injection. We discuss both methods of injection and compare each method., Proceedings of the North American Particle Accelerator Conference, NAPAC2019, Lansing, MI, USA

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

The electron-ion collider eRHIC aims at a luminosity around 10³⁴cm⁻²sec⁻¹, using strong cooling of the hadron beam. Since the required cooling techniques are not yet readily available, an initial version with a peak luminosity of 3*10³³cm⁻²sec⁻¹ is being developed that can later be outfitted with strong hadron cooling. We will report on the current design status and the envisioned path towards 10³⁴cm⁻²sec⁻¹ luminosity., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

After decades of successful operation as a 7-GeV synchrotron radiation source, the Advanced Photon Source is pursing a major upgrade that involves replacement of the storage ring with an ultra-low emittance multi-bend achromat design. Using a seven-bend hybrid multi-bend achromat with reverse bending magnets gives a natural emittance of 42 pm operated at 6 GeV. The x-ray brightness is predicted to increase by more than two orders of magnitude. Challenges are many, but appear manageable based on thorough simulation and in light of the experience gained from world-wide operation of 3^{\}text{rd}-generation light sources. The upgraded ring will operate in swap-out mode, which has allowed pushing the performance beyond the limits imposed by conventional operation., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

We have developed and tested a technique, which significantly improves the accuracy of the orbit bump method of local impedance measurement. This technique is based on in-phase sine-wave (AC) excitation of four fast correctors adjacent to the vacuum chamber section, impedance of which is measured. The narrow-band sine-wave signals provide better signal-to-noise ratio. Use of fast correctors to the beam excitation eliminates the systematic error caused by hysteresis. The systematic error caused by orbit drift is also suppressed because the measured signal is not affected by the orbit motion outside the excitation frequency range. The measurement technique is described and the result of experimental testing carried out at NSLS-II is presented., Proceedings of the 6th Int. Beam Instrumentation Conf., IBIC2017, Grand Rapids, MI, USA

The impedance budget for the eRHIC project is discussed at its earlier stage of development. As a first step, with the eRHIC lattice and beam parameters , we use the geometric impedances of the vacuum chamber components simulated for the NSLS-II project. The impedance budged will be updated next with more impedance data simulated for the optimized eRHIC vacuum components. It will allows us to keep track on the collective effects changes with more realistic components added to the ring., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

Two particle tracking codes, ELEGANT and SPACE, have been used to simulate the microwave instability in the APS storage ring. The total longitudinal wakepotential for the APS vacuum components, computed by GdfidL, has been used as the input file for the simulations. The numerical results have been compared with bunch length and the energy spread measurements for different single-bunch intensities., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

First experience with the beam-induced heating of the ceramics chambers in the NSLS-II storage ring has been discussed. Total five ceramics chambers are considered to be replaced due to overheating concern during of upcoming I_{a}v=500mA operations. The air cooling fans has been installed as a temporarily solution to remove heat., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

Several instability thresholds and special waveform beam pattern have been observed during measurements of the horizontal beam size change vs single bunch current by the synchrotron light monitor (SLM) camera installed in a low dispersion area of the NSLS-II storage ring. The electron beam energy spread from In-Vacuum Undulator (IVU) of the Soft Matter Interfaces (SMI) beam line confirmed the microwave beam pattern behavior as a current dependent effect. The numerically obtained total longitudinal wakepotential by the GdfidL code allowed us to compare the measured results with particle tracking simulations using the SPACE code. The instability thresholds behavior at different RF voltages are in some sort of overarching agreement., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The Advanced Photon Source has proposed an upgrade to a multi-bend achromat (MBA) with a proposed timing mode calls for 48 bunches of 15 nC each. In this mode of operation we find that phase space mismatch from the booster can drive large wakefields that in turn may limit the current below that of the nominal collective instability threshold. We show that collective effects at injection lead to emittance growth that makes usual off-axis accumulation very challenging. On-axis injection ameliorates many of these issues, but we find that transverse feedback is still required. We explore the role of impedance, feedback, and phase-space mismatch on transverse instabilities at injection., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

We discuss measurements, performed in the NSLS-II storage ring, of the synchronous phase shift as a function of single bunch current from beam loading parameters. The synchronous phase is calculated from the forward and reflected power measured in the RF cavities. The comparison with direct synchronous phase measurements shows good agreement., Proceedings of the 8th Int. Particle Accelerator Conf., IPAC2017, Copenhagen, Denmark

The microwave instability in the NSLS-II has been studied for the current configuration of insertion devices, 9 In-Vacuum Undulators (IVU's), 3EPU's, 3 Damping Wigglers. The energy spread as a function of single bunch current has been measured based on the frequency spectrum of IVU for X-Ray Spectroscopy (SRX) beam line. The results for two lattices, bare lattice with nominal energy spread 0.0005 and a lattice with one DW magnet gap closed (nominal energy spread 0.0007) are compared. In addition we used a Spectrum Analyzer to measure the beam spectrum. The instability thresholds for two different lattices cross-checked numerically using the particle tracking code SPACE and longitudinal impedance., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

A model to simulate the effect of a transverse feedback system is implemented in SPACE, a parallel, self-consistent code for collective effects. As an application, we discuss single bunch instability thresholds in the NSLS-II storage ring and compare the numerical results with measurements., Proceedings of the North American Particle Accelerator Conf., NAPAC2016, Chicago, IL, USA

Single bunch instabilities have been observed since the early stage of NSLS-II storage ring commissioning. After installing the super-conducting cavity, the single bunch instability threshold current was similar at 0.7mA. The instability was eventually determined to be due to transverse mode coupling. Microwave instability has been characterized using streak camera bunch profile, horizontal beam sizes at dispersion location and beam spectrums. Microwave instability threshold current dependency on bunch lengths and IUV gaps has been studied. Most recent experimental results will be presented in this paper., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

Longitudinal bunch profile has been measured at NSLS2 storage ring using streak camera. From the measured profile, bunch lengthening and synchronous phase information can be derived to study the single bunch collective effect. Single bunch lengthening effect has been measured for bare lattice and for other lattices with different insertion devices. The streak camera can also be setup for other beam physics studies, for example to measure the injection beam dynamics and fast ion effects. Y-z imaging was measured using cylindrical lenses. Single bunch y-z profile was measured at threshold current., Proceedings of the 4th International Beam Instrumentation Conference, IBIC2015, Melbourne, Australia

The injector for the National Synchrotron Light Source II storage ring consists of a 3 GeV booster synchrotron and a 200 MeV S-band linac. The linac was designed to produce either a single bunch with a charge of 0.5 nC of electrons or a train of bunches up to 300 ns long containing a total charge of 15 nC. The booster was designed to accelerate up to 15 nC each cycle. Linac commissioning was completed in April 2012. Booster commissioning was started in November 2013 and completed in March 2014. All of the significant design goals were satisfied including beam emittance, energy spread, and transport efficiency. While the maximum booster charge accelerated was only 10 nC this has proven to be more than sufficient for storage ring commissioning. The injector has operated reliably during storage ring operation since then. Results will be presented showing measurements of injector operating parameters achieved during commissioning and initial operation. Operating experience and reliability during the first year of NSLS-II operation will be discussed., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

As the newly constructed 3rd generation light source, NSLS-II is expected to provide the synchrotron radiation of ultra high brightness and flux with advanced insertion devices. To minimize the beam emittance, damping wigglers are used and the small aperture is located at the straight section with the damping wiggler and the corresponding vacuum camber is NEG coated. We used the local bump method to find the effect on the beam from the narrow aperture and the paper shows the results., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

Understanding the sources of impedance is critical to accelerator design, and only becomes more important as vacuum chambers become smaller and closer to the electron beam. The multibend achromat upgrade at the Advanced Photon Source (APS) requires small, 22-mm diameter vacuum chambers and even smaller (6 mm) gaps for the insertion devices, so that both rf heating and wakefield-driven transverse instabilities become important concerns. We discuss modeling the primary sources of geometric impedance using the electromagnetic finite difference codes GdfidL and ECHO, and how these codes are influencing vacuum and accelerator component design., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. As many facilities worldwide, NSLS II uses the EPICS control system to monitor and control all accelerator hardware. Control system studio (CSS) is used for simple tasks such as monitoring, display, setting of PVs. browsing the historical data, et. al. For more complex accelerator physics applications, a collection of scripts are mainly written in Python and part from Matlab during commissioning. With the close collaboration and fully support from control group, more and more CSS features were developed for operation convenience and several high level applications are interfaced with users in CSS panels for daily use based on softiocs. This paper will present the tools that we have been using for commissioning., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The typical problems occurring during commissioning of the first turns in the storage rings include shorted coils or reversed polarity of the magnets, cross-cabling of magnets power supplies and reversed polarity of BPMs. In this paper we describe a dedicated high level control application, which was created and utilized for commissioning of the first turns in NSLS-II storage ring., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

A conceptual design has been developed for a radio frequency (rf) pickup-type beam position monitor (BPM) for use in a multi-bend achromat (MBA) storage ring under consideration by the APS Upgrade project (APS-U). Beam feedback systems are expected to require fourteen rf BPMs per sector with exceptional sensitivity and mechanical stability. Simultaneously, BPM insertion length must be minimized to allow lattice designers the greatest freedom in selecting magnet lengths and locations. Envisioned is a conventional four probe arrangement integrated inside of a pair of rf-shielded bellows for mechanical isolation. Basic aspects of the design are presented along with the results of analyses which establish expected mechanical, electronic, and beam physics-related performance measures., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

An important operating mode for the multi-bend achromat (MBA) upgrade at the Advanced Photon Source (APS) calls for 200 mA average current divided evenly over 48 bunches. Ensuring that the desired 4.2 mA single bunch current can be stably stored requires a detailed understanding of the impedance in the MBA ring. We briefly discuss modeling sources of impedance using the electromagnetic codes GdfidL and ECHO, and how we then include both geometric and resistive wall wakefields using the tracking code elegant to predict collective instabilities. We first validate our procedures by comparing APS experimental measurements to tracking predictions using the APS storage ring impedance model. We then discuss the MBA impedance model, for which we find that a chromaticity of 5 units is sufficient to obtain the required 4.2 mA single bunch current. Finally, we mention certain design changes that may reduce the impedance and allow for a reduction in chromaticity., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

In this paper we describe our experience with commissioning of the first turns in the NSLS-II storage ring. We discuss the problems that we encountered and show how applying a dedicated first turns commissioning software allowed us to diagnose and resolve these problems., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

As another important milestone towards the final goal to store an average current of 500mA, the average current of 200mA, distributed within ~1000 bunches, was recently achieved in the NSLS-II storage ring after the installation of three Damping Wigglers and four In-Vacuum Undulators. First measurements of the collective effects and instability thresholds, both in single- and multi-bunch mode, are discussed., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The NSLS-II BPM Button design and its development process have been described. Subjects discussed include BPM Button impedance optimization, design and construction, production, BPM Button selection and a first temperature measurements at 200mA average current within 1200 bunches., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The NSLS-II storage ring has been commissioned during Phase 1 with 500 MHz 7-cell PETRA-III RF cavity. In this paper we present our first beam-measured data on instabilities and collective effects with a normal conducting RF system., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

We discuss coupled-bunch instabilities thresholds for the NSLS-II Storage Ring. In particular, we analyze thresholds from the High Order Modes (HOMs) of the PETRA-III 7-cell cavity. Beam dynamics simulations with the code OASIS, using the measured HOMs, will be compared with machine studies., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

Booster extraction presents a number of problems that include strengths and waveforms of the pulsed magnets and design of the vacuum chamber. Instabilities in the booster extraction may compromise the extracted beam quality deteriorating value of high-performance injector design. Here we discuss requirements and tolerances for the extraction system components and methods of increasing its performance., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

We discuss status and plans of development of the NSLS-II injector. The injector consists of 200 MeV linac, 3-GeV booster, transport lines and injection straight section. The system design is now nearly completed and the injector development is in the procurement phase. The injector commissioning is planned to take place in 2012., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The National Synchrotron Light Source at BNL was the first dedicated light source facility and it has now operated for more than 20 years. During this time the user community has grown to more than 2400 users annually. To insure that this vibrant user community has access to the highest quality photon beams, the NSLS is pursuing the design of a new ultra-high brightness (∼1021) electron storage ring, tailored to the 0.3-20 KeV photon energy range. We present our preliminary design and review the critical accelerator physics design issues.

We study decoherence effects due to second order chromaticity for small amplitude kicks, in order to estimate the energy spread from TbT data of the NSLS-II storage ring. The bare lattice case (no Damping Wigglers and Insertion devices) has been considered, due to the long transverse radiation damping time. To minimize the chromatic damping/antidamping from the slow-head tail effect, we used a short train of bunches distributed over consecutive rf-buckets with a high enough average current to obtain a good BPM signal. The vertical and horizontal betatron motion have been excited independently with pinger magnets. In this contribution we limit the discussion to the horizontal case., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. While the installation activities in the booster-synchrotron are nearly completed and waiting for the authorization to start the booster commissioning, the injector and accelerator physics group have engaged into the Integrated Testing phase. We did the booster commissioning with simulated beam signals, called extended integrated testing (EIT) to prepare for the booster ring commissioning. It is to make sure the device function along with utilities, timing system and control system, to calibrate diagnostics system, debug High Level Applications, test and optimize all the operation screens to reduce the potential problems during booster commissioning with beam., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA