The NSLS-II at Brookhaven National Laboratory (BNL) started the user beam service in early 2015, and is currently operating 13 of the insertion device (ID) and beamlines as well as constructing new beamlines. The fast machine protection consists of an active interlock system (AIS), beam position monitor (BPM), cell controller (CCs) and front-end (FE) systems. The AIS measures the electron beam envelop and the dumps the beam by turning off RF system, and then the diagnostic system provides the post-mortem data for an analysis of which system caused the beam dump and the machine status analysis. NSLS-II post-mortem system involves AIS, CCs, BPMs, radio frequency system (RFs), power supply systems (PSs) as well as the timing system. This paper describes the AIS architecture and PM performance for NSLS-II safe operations.

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.

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.

The injector for the National Synchrotron Light Source II (NSLS-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 in a train of bunches up to 300 ns long. 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 and operation. The injector has operated reliably during storage ring operation since then. Results will be presented showing measurements of linac and booster operating parameters achieved during commissioning and initial operation. Operating experience and reliability during the first year of NSLS-II operation will be discussed.

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. The SR is designed to work in top-off injection mode. The injection straight includes a septum and four fast kicker magnets with independent amplitude and timing control. The beam injection is designed as 9.5 mm off-axis in x plane and on-axis injection in y plane. To capture the injected beam within the SR acceptance for high injection efficiency, it requires 6-D phase space match. Besides that, the fast kickers formed local bump is also required to be locally to minimize the injected beam extra betatron oscillation and keep the stored beam disturbance within the specification, 10 % beam size to minimize the injection transient. This paper will present our injection commissioning experience.

NSLS-II (1), the new 3GeV 3 rd generation light source presently under construction at Brookhaven National Laboratory will provide ultra-bright synchrotron radiation of 10 21 ·photons·s -1 ·mm -2 mrad -2 ·0.1%BW -1 @ 2keV and high photon flux of 10 15 ·photons·s -1 ·0.1%BW -1 . The facility will support a minimum of 60 beamlines. Construction started in 2009 and commissioning is expected to be completed in 2014. This report will provide a description of the NSLS-II design and will summarize the status of the construction project.

The NSLS-II is a state-of-the-art 3 GeV synchrotron light source under construction at Brookhaven National Laboratory. Since 2012, the injector system gradually moves to the commissioning stage. To make the commissioning smooth and efficient, an emphasis was put on the sub-system integration test to make sure the injector system components function along with utilities, timing system and control system, to calibrate diagnostics system and to test high level applications with simulated beam signals and required hardware. In this paper, we report our experience with the integrated testing of the NSLS-II injector.

We review the work carried out in the X13 R&D Straight Section of the NSLS X-Ray Ring on small gap in-vacuum undulators (IVUNs). Then we discuss: (1) plans to replace the pure permanent magnet undulator in X13 by a hybrid design providing stronger magnetic fields, enhancing the tunability of the device; (2) plans to install hybrid IVUNs in the two RF straights of the X-Ray Ring, increasing the number of insertion devices in the X-Ray Ring to eight; (3) the possibility of reducing the vertical beta function in the X13 straight from 0.33 m down to 0.16 m. This reduction in beta function would allow us to decrease the usable undulator gap from 3 mm down to 2 mm, further increasing the tuning range.

The NSLS X-Ray Ring is now being operated with a low emittance lattice. The horizontal emittance was reduced to 45 nm-rad from 90 nm-rad at 2.584 GeV while maintaining a vertical emittance of 0.1 nm-rad. The electron beam lifetime was unaffected by the emittance reduction because the decrease in the dispersion in the dipole magnets compensate for the higher bunch density in the Touschek effect. The lattice will also be implemented at 2.8 GeV after the strength of the focusing sextupoles is increased. The effect of low emittance operation on the synchrotron radiation users will be discussed.

The superconducting 5 pole, 5 Tesla wiggler which has been operating in the X-17 straight section of the X-ray storage ring at the National Synchrotron Light Source (NSLS) since 1989 will soon be replaced by a new wiggler being built by Oxford instruments with lower operating costs, higher reliability, and greater performance. The new wiggler has three modes of operation: the full wiggler with 11 poles producing 3.0 T, the partial wiggler with 5 poles at 4.7 T, and the wavelength shifter with a single pole producing 5.5 T. The full wiggler, optimized for the digital subtraction radiography program, will produce the same X-ray flux at the 33 KeV iodine K-edge as the existing wiggler operating at 4.7 T but will reduce the higher energy harmonics delivered to the target. The partial wiggler will deliver the same flux for solid state physics experiments as the existing wiggler, and the wavelength shifter will provide an elliptically polarized X-ray beam that is not now available.

A proposed upgrade to the NSLS X-Ray Ring is described that will allow the storage of a 2.4 A, 3 GeV electron beam using technology developed for the PEP-II B factory at SLAC. In this configuration, a peak flux of greater than 1016 photons/sec/0.1% bandwidth/5 mrad will be produced. The four existing 53 MHz RF cavities will be replaced with eight 476 MHz cavities. Two 952 MHz cavities will also be used to lengthen the bunch, increasing the Touschek life-time. A copper vacuum chamber will be needed to absorb the increased synchrotron radiation and a feedback system may be needed to prevent multi-bunch instabilities.

Transition radiation is emitted when a relativistic, charged particle passes between media with different dielectric constants. Most often the transition is between vacuum and a conductor. The transition radiation spectrum theoretically extends from DC to extremely short wavelengths determined by the particle energy. In practice, the long wavelengths are cut off in the millimeter or centimeter range by the shielding effect of the vacuum chamber containing the particles. This report briefly discusses this experiment and some observations.

A fill rate monitor has been developed for the NSLS storage rings to allow machine tuning over a very large dynamic range of beam current. Synchrotron light, focused on a photodiode, produces a signal proportional to the beam current. A charge balancing circuit processes the diode current, creating an output signal proportional to the current injected into the ring. The unit operates linearly over a dynamic range of 120 dB and can resolve pulses of injected beam as small as 1 /spl mu/A.

Research into the production and utilization of short electron bunches at Brookhaven National Laboratory is underway at the Source Development Laboratory (SDL) and Accelerator Test Facility (ATF). Projects planned for the SDL facility include a 210 MeV electron linac with a dipole chicane that is designed to produce 100 μm long bunches and a compact electron storage ring that will use superconducting RF to produce sub‐millimeter bunches. The ATF has a 30–70 MeV linac that will serve as the injector for laser accelerators that will bunch the beam into to micron‐length bunches. Coherent transition and synchrotron radiation from the short bunches will be used for beam diagnostics and infrared experiments.

A self-triggered beam position monitor (BPM) has been developed for the NSLS injection system to provide single pulse orbit measurements in the booster synchrotron, linac, and transport lines. The BPM integrates the negative going portion of 3 nS wide bipolar pickup electrode signals. The gated, self triggering feature confines critical timing components to the front end, relaxing external timing specifications. The system features a low noise high speed FET sampler, a fiber optic gate for bunch and turn selection, and an inexpensive interface to a standard PC data acquisition system

The NSLS booster is a 7 to 750 MeV synchrotron with a 0.7 Hz repetition rate. The betatron tunes can change during acceleration by as much as 0.1 units, causing beam loss as they cross resonance lines. Precise measurements with a conventional swept spectrum analyzer have always been difficult because of the rapid variation of tune as the magnets are ramped. We are now using a system based on a Tektronix 3052 Digital Signal Processing System that can obtain an effectively continuous measurement of both the horizontal and vertical tunes during a single acceleration cycle. Betatron oscillations are stimulated for the measurements by applying broadband noise to the beam through stripline electrodes. We will describe the instrumentation, our measurements of tune as a function of time during the acceleration cycle, and the resulting improvements to the booster operation.

We examine the properties of an elliptically polarized wiggler that will generate circularly polarized photons with an energy spectrum of 3-12 keV. The vertical wiggler magnetic field is produced by permanent magnets while the horizontal wiggler field is generated by electric coils capable of AC excitation. The radiation parameters of the wiggler are presented. Numerical values are calculated for radiation from the wiggler. A conceptual design for such a wiggler is discussed. We consider AC excitation of the wiggler to produce the time modulation of the elliptic polarization. The power dissipated in the vacuum chamber due to the eddy current is considered