Article

Present status and first results of the final focus beam line at the KEK Accelerator Test Facility

Physical Review Special Topics - Accelerators and Beams (Impact Factor: 1.52). 11/2011; 13(4). DOI: 10.1103/PhysRevSTAB.13.042801
Source: OAI

ABSTRACT ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and installation were completed and beam commissioning started, supported by an international team of Asian, European, and U.S. scientists. The present status and first results are described.

Download full-text

Full-text

Available from: Christina Swinson, Aug 02, 2015
0 Followers
 · 
217 Views
  • Source
    • "A detailed description of the ATF at KEK can be found in [12] [15] [16]. The 1.28 GeV damping ring (DR) has a revolution period of 462 ns and operates at the radio frequency (RF) of 357 MHz (165 RF buckets spaced by 2.8ns). "
    [Show abstract] [Hide abstract]
    ABSTRACT: As part of the positron source R&D for future $e^+-e^-$ colliders and Compton based compact light sources, a high finesse non-planar four-mirror Fabry-Perot cavity has recently been installed at the ATF (KEK, Tsukuba, Japan). The first measurements of the gamma ray flux produced with a such cavity using a pulsed laser is presented here. We demonstrate the production of a flux of 2.7 $\pm$ 0.2 gamma rays per bunch crossing ($\sim3\times10^6$ gammas per second) during the commissioning.
    Journal of Instrumentation 11/2011; 7(01). DOI:10.1088/1748-0221/7/01/P01021 · 1.53 Impact Factor
  • Source
    • "Both beam position and angular jitter should be controlled along the beam delivery system during multi-bunch operation in order to stabilise the vertical beam position jitter to the nanometre level precision at the IP. The ATF2 final focus test beam facility [1] is currently progressing towards the achievement of transverse beam sizes of about 40 nm at the IP. At the same time, R&D activities have also started to achieve the second ATF2 goal, i.e. the control of the beam position at the level of 5% of the rms vertical beam size at the IP. Figure 1 shows a schematic of the ATF2 beamline. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Pulse-to-pulse orbit jitter, if not controlled, can drastically degrade the luminosity in future linear colliders. The second goal of the ATF2 project at the KEK accelerator test facility is to stabilise the vertical beam position down to approximately 5% of the nominal rms vertical beam size at the virtual Interaction Point (IP). This will require control of the orbit to better than 1 micrometre at the entrance of the ATF2 final focus system. In this report simulation studies are presented for vertical jitter propagation through the ATF2 extraction line and final focus system, and the jitter is evaluated at the IP. For these studies pulse-to-pulse vertical jitter measurements using three stripline beam position monitors are used as initial inputs. These studies are performed for the case of a bunch-train with three bunches, but could easily be extended for a larger number of bunches. The cases with and without intra-train orbit feedback correction in the extraction line of ATF2 are compared.
  • Source
    • "INTRODUCTION ATF2 [1] [2] "
    [Show abstract] [Hide abstract]
    ABSTRACT: The ATF2 project is the final focus system prototype for ILC and CLIC linear collider projects, with a purpose to reach a 37nm vertical beam size at the interaction point. During initial commissioning, we started with larger than nominal ?-functions at the IP, to reduce the effects from higher-order optical aberrations and thereby simplify the optical corrections needed. We report on simulation studies at two different IP locations developed based on waist scan, dispersion, coupling and ? function multiknobs correction in the large ? optics of ATF2, in the presence of two kinds of magnet inaccuracies (quadrupole gradient and roll errors) to generate all possible linear optics distortions at the IP. A vertical beam size which is very close to the nominal beam size is obtained based on the simulation study.
Show more