Article

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

[more]
(Impact Factor: 1.66). 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.

### Full-text

Available from: Christina Swinson
• 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). "
##### Article: Production of gamma rays by pulsed laser beam Compton scattering off GeV-electrons using a non-planar four-mirror optical cavity
[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.
Full-text · Article · Nov 2011 · Journal of Instrumentation
• 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. "
##### Article: Pulse-to-pulse Orbit Jitter Propagation in Multi-bunch Operation at the KEK Accelerator Test Facility 2 (ATF2)
[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.
Full-text · Article · Oct 2011
• Source
• "More details about the ATF2 accelerator, its optics and diagnostics systems as well as details about the commissioning so far can be found in [1]. Details about the tuning process and simulation studies thereof can be found in [2]. "
##### Article: Operational Experiences Tuning the ATF2 Final Focus Optics Towards Obtaining a 37nm Electron Beam IP Spot Size
[Hide abstract]
ABSTRACT: The primary aim of the ATF2 research accelerator is to test a scaled version of the final focus optics planned for use in next-generation linear lepton colliders. ATF2 consists of a 1.3 GeV linac, damping ring providing low-emittance electron beams (<12pm in the vertical plane), extraction line and final focus optics. The design details of the final focus optics and implementation at ATF2 are presented elsewhere* . The ATF2 accelerator is currently being commissioned, with a staged approach to achieving the design IP spot size. It is expected that as we implement more demanding optics and reduce the vertical beta function at the IP, the tuning becomes more difficult and takes longer. We present here a description of the implementation of the overall tuning algorithm and describe operational experiences and performances
Full-text · Article · May 2010