Eric Blum

Photoinjected energy recovery linac upgrade for the National Synchrotron Light Source

We describe a major paradygm shift in in the approach to the production of synchrotron radiation This change will considerably improve the scientific capabilities of synchrotron light sources. We introduce plans for an upgrade of the National Synchrotron Light Source (NSLS). This upgrade will be based on the Photoinjected Energy Recovering Linac (PERL). This machine emerges from the union of two technologies, the laser-photocathode RF gun (photoinjector) and superconducting linear accelerators with beam energy recovery (Energy Recovering Linac). The upgrade will bring the NSLS users many new insertion device beam lines, brightness greater than 3rd generation light-sources and ultra-short pulse capabilities, not possible with storage ring light sources.

A superconducting wiggler magnet for the NSLS X-ray ring

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.

NSLS-II Active Interlock System and Post-Mortem Architecture

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. INTRODUCTION NSLS-II storage ring (SR) completed commissioning in 2014 [1-2], and started operation and user beam service in 2015. In 2016, up to 16 insertion devices were installed as well as the user service with two superconducting RF cavity and 250 mA stored beam current. The active interlock system is one of the major machine protection systems from the synchrotron radiation. The main purpose of AIS is to protect the insertion device vacuum chamber and the storage ring vacuum chamber from missteered synchrotron radiations from IDs and Dipole magnets radiation. The required active interlock insertion device (AI-ID) system response time is maximum < 1 ms, because through 1 ms duration damping wiggler (DW) aluminum vacuum chamber will increase the surface temperature to 100 C at 1.5 mrad vertical angles. For the storage ring bending magnet protection, which is called the active interlock bending magnet (AI-BM), the response time is 10 ms. Allowance envelop defined for protecting the device and configured offset is xy=+/-0.5 mm, and the angle is xy=+/0.25 mrad. This paper will present the AIS hardware configuration, FPGA internal functions, global PM hardware configuration and internal timing diagrams. NSLS-II operation status and the future plan. SYSTEM DESCRIPTION NSLS-II AIS showed robust and stable performance during operation, and lots of flexibilities for implementing machine protection from the synchrotron radiation and critical machine faults. One of the benefits is the real-time offset/angle calculation, and all of the decision engines are located at the central FPGA core, which is called C31. The AIS hardware layout is shown in Fig 1, and more details of the system and each device regarding characteristics and functions are described in [1-2]. AI Database And Web interface softIO C1 softIO C2 AI FPGA Interfa ce RF Transmitter and LLRF C OPI-CSS PM Client DISK Storage EPS RF Transmitter and LLRF D Input signals from machine Ethernet cable (1 Gbps) Wire (TTL) SDI fiber network (5 Gbps) Cell 1 Cell 30 SDI CW SDI CCW Timing

Toward a systems biology software toolkit

Insight to complex problems may be revealed when domain data sets are viewed or structured in new and innovative ways. Systems approaches to biomedical problems fundamentally involve forecasting, and a deliberate integration of diverse data sources. Adding a clinical proteomic dimension to these developing efforts affirms the ultimate aims of enhanced diagnostic prediction, maximizing the possibility for a rational therapy individualized to a patients pathologic process, and thus, improving patient outcomes. Consistent with these evolving goals, computer-aided diagnostic systems are rapidly approaching a new paradigm involving the integration of medical imaging with high throughput molecular medicine tests. As medical imaging systems become more sensitive in finding anatomic anomalies, their lack of specificity becomes much more of a clinical dilemma. Proteomic tests may be used to help resolve the lack of specificity of imaging findings. A synergistic test composed of a targeted imaging study correlated with a genomic or proteomic test(s), offers the potential of a tremendous medical advancement. Bioinformatic software toolkits are crucial components of these systems. Open source software provides a mechanism for leveraging existing toolkits, sharing expertise, accelerating development, and furthering biomedical, software, and systems sciences in new and complex multi-disciplinary fields. Our evolving toolkit utilizes components from several existing open source projects. It will initially be customized for serum proteomic pattern diagnostics, which will be used in the upcoming NCI/CCR Clinical Trial involving the monitoring for ovarian cancer recurrence.

Millimeter wave coherent synchrotron radiation in a compact electron storage ring

Installation of a 2856 MHz RF system into the XLS compact electron storage ring would allow the generation of millimeter wave coherent synchrotron radiation. Operating at 150 MeV, one could produce bunches containing on the order of 2/spl times/10/sup 7/ electrons with a bunch length /spl sigma//sub LO/=0.3 mm, resulting in coherent emission at wavelengths above 0.8 mm. The characteristics of the source and the emitted radiation are discussed. In the case of 100 mrad horizontal collection angle, the average power radiated in the wavelength band 1 mm /spl les//spl lambda//spl les/2 mm is 0.3 mW for single bunch operation and 24 mW for 80 bunch operation. The peak power in a single pulse of a few picosecond duration is on the order of one watt. By reducing the momentum compaction, the bunch length could be reduced to /spl sigma/(LO)=0.15 mm, resulting in coherent synchrotron radiation down to 500 /spl mu/m.

Charge balancing fill rate monitor

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.

NSLS source development laboratory

The National Synchrotron Light Source (NSLS) has initiated an ambitious project to develop fourth generation radiation sources. To achieve this goal, the Source Development Laboratory (SDL) builds on the experiences gained at the NSLS, and at the highly successful BNL Accelerator Test Facility. The SDL accelerator system will consist of a high brightness short pulse linac, a station for coherent synchrotron and transition radiation experiments, a short bunch storage ring, and an ultra-violet free electron laser utilizing the NISUS wiggler. The electrons will be provided by a laser photocathode gun feeding a 210 MeV S-band electron linac, with magnetic bunch compression at 80 MeV. Electron bunches as short as 100 micrometers with 1 nC charge will be used for pump-probe experiments utilizing coherent transition radiation. Beam will also be injected into a compact storage ring which will be a source of millimeter wave coherent synchrotron radiation. The linac will also serve as the driver for an FEL designed to allow the study of various aspects of single pass amplifiers. The first FEL configuration will be as a self-amplified spontaneous emission FEL at 900 nm. Seeded beam and sub-harmonic seeded beam operations will push the output wavelength below 200 nm. Chirped pulse amplification operation will also be possible, and a planned energy upgrade (by powering a fifth linac section) to 310 MeV will extend the wavelength range of the FEL to below 100 nm.

Short bunch research at Brookhaven National Laboratory

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 {mu}m 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.