BNL, Upton, Long Island, New York, USA
BNL, Upton, Long Island, New York, USA
NSLS-II is a third generation light source that is under construction at the Brookhaven National Laboartory. The 3GeV 792m long 30-cell storage ring will be commissioned in 2014. The emittance is lowered from 2nm to 1nm by three 7m damping wigglers. This paper will discuss the future emittance reduction approaches for NSLS-II. One option is installing more damping wigglers; an alternative solution is to manipulate the damping partition by shifting the chromatic quadrupoles horizontally. Both methods can lower the emittance effectively; however, the second method does not occupy the user straights. When the quarupoles are moved, the orbit and thus the vacuum chamber need to be redesigned, and beam dynamics could be affected. In the paper we will compare the lattice properties for the two options, and address the potential issues.
BNL, Upton, Long Island, New York, USA
NSLS II is designed to work in top-off injection mode. The goal is to minimize the disturbance of the injection transient on the users. The injection straight includes a septum and four fast kicker magnets. The pulsed magnet errors will excite a betatron oscillation. This paper gives the formulas of each error contribution to the oscillation amplitude at various source points in the ring. These are compared with simulation results. Based on the simple formulas, we can specify the error tolerances on the pulsed magnets and scale it to similar machines.
BNL, Upton, Long Island, New York, USA
Many modern light sources are operating in top-off injection mode or are being upgraded to top-off injection mode. For top-off injection mode, the storage ring always has the stored beam and injected beam. So the BPM data is the mixture of both beam positions and the injected beam position cannot be measured directly. We propose to use a BPM with special electronics in NSLS II storage ring to retrieve the injected beam trajectory with the SVD method. The BPM has the capability to measure bunch-by-bunch beam position. We also need another system to measure the bunch-by-bunch beam current. The injected beam trajectory can be measured and monitored all the time without dumping the stored beam. We can adjust and optimize the injected beam trajectory to maximize the injection efficiency. We can also measure the storage ring acceptance by mapping the injected beam trajectory.
BNL, Upton, Long Island, New York, USA
The NSLS II beam injection works with two septa and four fast kicker magnets. The kicker power supplies each produce a two revolution periods pulsed field, 5.2μs half sine waveform, using ~5kV drive voltage. The corresponding close orbit bump amplitude is ~15mm. It is desired that the bump they produce is transparent to the users for top-off injection. However, high voltage and short pulse power supplies have challenges to maintain pulse-to-pulse stability and magnet-to-magnet reproducibility. To minimize these issues, we propose to implement a DC local bump on top of the fast bump to reduce the fast kicker strength by a factor of 2/3. This bump uses two ring corrector magnets plus one additional magnet at the septum to create a bump. Additionally, these magnets could provide a DC bump, which would simulate the effects of a movable septum on the store beam lifetime. This paper presents the detail design of this DC injection bump and related beam dynamics.
BNL, Upton, Long Island, New York, USA
We propose an upgrade R&D project for NSLSII to generate sub-pico-second short x-ray pulses using laser slicing. In this paper we discuss the basic parameters for this system and present a specific example for a viable design and its performance. Since the installation of the laser slicing system into the storage ring will break the symmetry of the lattice, we demonstrate it is possible to recover the dynamical aperture to the original design goal of the ring.
BNL, Upton, Long Island, New York, USA
National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3- GeV, high-flux and high-brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system has extruded aluminium chambers, with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers are used to intercept the un-used bending magnet radiation. In-situ bakeout is implemented to achieve fast conditioning during initial commissioning and after interventions.
BINP SB RAS, Novosibirsk, Russia
BNL, Upton, Long Island, New York, USA
Danfysik A/S, Jyllinge, Denmark
BNL, Upton, Long Island, New York, USA
NSLS-II injection straight section consists of the pulsed and DC/Slow bumps, septa system, beam trajectory correction and diagnostics systems. In this paper we discuss overall injection straight layout, preliminary element designs, specifications for the pulsed and DC magnets and their power supplies, vacuum devices and chambers and diagnostics devices.