• F. Sannibale, K.M. Baptiste, J.N. Corlett, T.M. Huang, S. Kwiatkowski, D. Li, J. Qiang, J.W. Staples, R.P. Wells, L. Yang, A. Zholents
  LBNL, Berkeley, California
• J.W. McKenzie
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231

A high-brightness high-repetition rate photo-injector based on a normal conducting 187 MHz RF cavity design capable of CW operation is under construction at the Lawrence Berkeley National Laboratory. A cathode field of ~20 MV/m accelerates electron bunches to 750 keV with peak current, energy spread and transverse emittance suitable for FEL and ERL applications. A vacuum load-lock mechanism is included and a 10 picoTorr range vacuum capability allows most types of photocathodes to operate at a MHz repetition rate with present laser technology. The status of the project is presented.

• C. Steier, L. Yang
  LBNL, Berkeley, California

Funding: This work was supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The Touschek lifetime in low energy or small emittance lepton storage rings strongly depends on the particle density in bunches. In the usual parameter range, this dominates other effects and the lifetime gets shorter with higher the bunch density, i.e. with smaller beam emittance. However, once one gets to extremely small horizontal emittances, this is no longer the case. Since the Touschek scattering process is an energy transfer from the transverse plane to the longitudinal one, the Touschek lifetime actually increases, once the transverse temperature (i.e. emittance) gets small enough. In the usual Touschek lifetime formulas, this is accounted for with a complicated multiparameter function (form factor). This paper presents to our knowledge the first direct measurements of the Touschek lifetime in this region of reversed dependence on horizontal emittance, as well as comparison with theory. The measurements were carried out at the ALS at reduced beam energy and ultrasmall horizontal emittance.

• L. Yang, D. Robin, F. Sannibale, C. Steier, W. Wan
  LBNL, Berkeley, California

Funding: Work supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

Multiobjective optimization has been used in many fields including accelerator related projects. Here we use it as a powerful tool for lattice design and optimization, which includes betatron functions, brightness.

• C. Steier, L. Yang
  LBNL, Berkeley, California

Funding: This work was supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

Frequency map analysis is being widely used, nowadays, both in simulations to design or improve accelerator lattices, as well as in experiments to study the transverse nonlinear dynamics in accelerators. A significant challenge to the use of frequency map analysis in experiments is the usually very fast decoherence of transverse oscillations, caused by the large nonlinearities of state-of-the-art lattices. Due to the decoherence, the center of mass oscillations of bunches often disappear in less than 100 turns. A potential way to get around this limitation is the use of multiple BPMs distributed (symetrically) around the storage ring. The presentation will describe the challenges multi-BPM frequency map analysis poses as well as initial results using the ALS.

• D. Robin, C. Steier, L. Yang
  LBNL, Berkeley, California

Funding: Supported by DOE BES contract DE-AC03-76SF00098.

Recently there has been a proposal to use pulsed high order multipole elements for injection. One of the advantages of this proposed injection scheme would be that it would be less disruptive to the stored beam and thus advantageous for Top-off operation. In addition to Top-off, such novel injectors might open the door to operating storage rings in more desirable lattice settings. In this paper we will explore some of the possibilities for taking advantage of high order multipole pulsed kick injection.