SLAC, Menlo Park, California
ANL, Argonne
DESY, Hamburg
Funding: *Work supported by the DOE under contract DE-AC02-76SF00515
The FLASH L-Band superconducting (SC) accelerator facility at DESY has a LLRF system that is similar to that envisioned for ILC. This system has extensive monitoring capability and was used to gather performance data relevant to ILC. In particular, waveform data were recorded with beam off for three, 8-cavity cryomodules to evaluate the input rf stability, perturbations to the SC cavity frequencies and the rf overhead required to achieve constant gradient during the 800 μs pulses. In this paper, we discuss the measurements made in September 2008 and the data analysis procedures, and present key findings on the pulse-to-pulse input rf and cavity field stability.
DESY, Hamburg
Funding: This work is supported by the Commission of the European Communities under the 6th Framework Programme "Structuring the European Research Area", contract number RIDS-011899.
The International Linear Collider (ILC) relies on very high beam powers and very small beam emittance to achieve the ambitious luminosity of 2·10+34 cm-2s-1. The potential for damage to the accelerator hardware in the event of some machine failure will require a sophisticated machine protection system. The small apertures in the Beam Delivery System (BDS) - specifically the collimators (by definition the smallest apertures in the machine) are particularly critical. Possible failures in the Main Linac of the ILC and their impact on the BDS are studied using the MERLIN C++ library*. We show that the machine is safe for at least one bunch in case of one of the described failures; a fast abort system is designed to safely extact the remainder of the bunches in the pulse to a dump. Investigated are phase and voltage shifts of the klystrons, quadrupole and corrector coil failures.
*Merlin - A C++ Class Library for Accelerator Simulations; http://www.desy.de/~merlin.
DESY, Hamburg
ANL, Argonne
Fermilab, Batavia
KEK, Ibaraki
Funding: Work at Argonne supported by U.S. Department of Energy, Office of Science, office of Basic Energy, Sciences, under Contract No. DE-AC02-06CH11357
XFEL and ILC both intend to accelerate long beam pulses of a few thousand bunches and high average current. It is expected that the superconducting accelerating cavities will eventually be operated close to their respective gradient limits as they are pushed to higher energies. In addition, a relative energy stability of <10-4 must be maintained across all bunches. These parameters will ultimately push the limits of several sub systems including the low-level rf control, which must properly compensate for the heavy beam loading while avoiding problems from running the cavities close to their quench limits. An international collaboration led by DESY has begun a program of study to demonstrate such ILC-like conditions at FLASH, which serves as a prototype for both XFEL and ILC. The objective is to achieve reliable operation with pulses of 2400 3-nC bunches spaced by 330 ns (a current of 9 mA) while meeting the required energy stability and while operating accelerating cavities close to their quench limits. Other goals include measurement of cryoload from HOM heating and evaluation of rf power overhead for the ILC. The paper will describe the program and report recent results.
DESY, Hamburg
Fermilab, Batavia
KEK, Ibaraki
With a now extended plan to 2012, the ILC Global Design Effort Technical Design Phase focuses on key R&D to verify performance goals and to reduce both technical risk and cost. This talk will review the progress during the last two years, and plans for the future.
