A general modeling framework is introduced that allows for the solution to magnetic field perturbations due to mechanical and magnetic tolerances in hybrid undulators. For example, both geometric pole errors and permanent magnet block geometry and strength errors can be considered. Of particular significance is the scaling of the various errors with variations in the gap of the device. In this work, the perturbation analysis is presented along with specific examples of errors found in hybrid undulators.

Elliptically Polarizing Undulators [1] that provide full photon polarization control also have fast, intrinsic transverse roll-off of the magnetic field. The roll-off is especially fast for vertical polarization settings, and can have big detrimental effects on the nonlinear single particle dynamics. Particularly low and medium energy light sources and long period EPUs are prone to those effects. The three existing 50 mm period EPUs at the ALS have been retrofitted with shims to correct for these dynamic multipole effects and a new 90 mm period device which otherwise would have caused a huge reduction in dynamic aperture has been shimmed before installation. Beam dynamics measurements on all devices show that the shimming works very well and user operation with the long period EPU has begun.

The pulsed wire technique is an attractive option for the measurement of undulators where the measurement access is restricted due to, for example, narrow undulator gaps or cryogenic environments in the case of superconducting undulators. Using the pulsed wire technique, direct measurements of the first and second integrals of the magnetic field can be obtained. However, one of the main limitations of this technique is the error introduced by dispersive wave motion, due to the finite flexural rigidity of the wire. For the measurement of the first integral of the magnetic field, an error is also introduced by the use of a current pulse with finite pulse width. In this paper, a general solution is presented for dispersive wave motion in pulsed wire measurements. A method for the measurement of the dispersive wave speed is presented and demonstrated through experimental examples. An algorithm is derived which corrects the dispersion and finite pulse-width errors in the measurement of first magnetic field integrals and the dispersion error in the measurement of second magnetic field integrals. The effectiveness of the correction algorithms is demonstrated through experimental measurements, and the results are compared with Hall probe measurements on a short undulator. © 2013 Elsevier B.V.

The Advanced Light Source is a 3rd generation light source in operation since 1993. This light source is providing state of the art performance to more than 40 beamlines and their users thanks to the upgrades that have been completed over the last few years. Higher photon beam brightness is expected to become available to users in the near future through a new upgrade with the introduction of 48 sextupoles in the ALS lattice. Introducing new combined function magnets in an existing storage ring is a challenge due to the limited space available and a balance had to be found between magnet performance and spatial constraints. Moreover, the existing steering magnets will be replaced by the harmonic sextupoles. Therefore predicting the hysteresis behavior of the harmonic sextupole steering functions became critical for those included in the fast-orbit feedback loop (22 of them). After a brief introduction to the motivation for the upgrade and the scope of the project, we develop in this paper the different constraints driving the three required combined function magnet designs as well as their expected performance. © 2011 Elsevier B.V. All rights reserved.

Forty-eight harmonic sextupole magnets with integrated dipole correctors and skew quadrupole coils will be introduced in the Advanced Light Source Storage Ring. These new magnets are required to allow the ALS to provide the 40 beamline users with higher photon beam brightness (factor of 2 or 3). Introducing new combined-function magnets in an existing storage ring is a challenge due to the limited space available and a balance had to be found between magnet performance and spatial constraints. Consequently four different magnet designs were required. The calculation and simulation results obtained for each design as well as the impact of the different design choices on the magnetic performance are developed in this paper. © 2002-2011 IEEE.

The Advanced Light Source is one of the earliest 3rd generation light sources. With an active upgrade program it has remained competitive over the years. The latest in a series of upgrades is a lattice upgrade project that was started in 2009. When it will be completed, the ALS will operate with a horizontal emittance of 2.2 nm and an effective emittance of 2.6 nm. Combined with the high current of 500 mA and the small vertical emittance the ALS already operates at, this upgrade will keep it competitive for years to come. This paper summarizes the status of the upgrade, including beam dynamics studies and lattice optimizations as well as the magnet design.

The Advanced Light Source (ALS) at Berkeley Lab while one of the earliest 3rdgeneration light sources remains one of the brightest sources for soft x-rays worldwide. Amultiyear upgrade of the ALS is currently under way, which includes new and replacementx-ray beamlines, a replacement of many of the original insertion devices and many upgradesto the accelerator. The accelerator upgrade that affects the ALS performance most directlyis the ALS brightness upgrade, which will reduce the horizontal emittance from 6.3 to 2.2nm (2.6 nm effective). This will result in a brightness increase by a factor of three forbendmagnet beamlines and at least a factor of two for insertion device beamlines. Magnetsfor this upgrade are currently in production and will be installed starting later thisyear. Copyright © 2012 by IEEE.

The Advanced Light Source (ALS) at Berkeley Lab remains one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is underway, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade [1], which reduces the horizontal emittance from 6.3 to 2.0 nm (2.5 nm effective). Magnets for this upgrade were installed in late 2012 and early 2013 followed by user operation with the reduced emittance.

The Advanced Light Source (ALS) at Berkeley Lab remains one of the brightest sources for soft x-rays worldwide. A multiyear upgrade of the ALS is underway, which includes new and replacement x-ray beamlines, a replacement of many of the original insertion devices and many upgrades to the accelerator. The accelerator upgrade that affects the ALS performance most directly is the ALS brightness upgrade, which reduced the horizontal emittance from 6.3 to 2.0 nm (2.5 nm effective). Magnets for this upgrade were installed starting in 2012 followed by a transition to user operations with 2.0 nm emittance in spring 2013. Copyright © 2013 by JACoW.

The Advanced Light Source (ALS) is a thirdgeneration light source in operation since 1993. This light source is providing state-of-the-art performance to more than 40 beamlines and their users, due to the upgrades that have been completed over the last few years. The storage ring upgrade project that is developed here will allow the ALS to provide the 40 beamline users with higher photon beam brightness (factor of 2 or 3) by having its storage ring lattice modified. Forty-eight harmonic sextupole magnets with integrated dipole correctors and skew quadrupole coils will be introduced, which will require a level of installation activity not seen at the ALS since its original construction in 1991. Introducing new combined-function magnets in an existing storage ring is a challenge due to the limited space available and a balance had to be found between magnet performance and spatial constraints. After an introduction reviewing the characteristics of the three design families of the 48 combined-function magnets, the magnet fabrication and installation are developed along with analyses based on the magnetic measurements and the ALS storage ring commissioning results.