JAI, Oxford
ATOMKI, Debrecen
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
We present the results of beam tests of the FONT4 ILC prototype intra-train beam feedback system. The system comprises a stripline BPM, a fast analogue BPM signal processor, a custom FPGA-based digital feedback board, a high-power fast-response drive amplifier, and a stripline kicker. The hardware was deployed at the Accelerator Test Facility at KEK. Trains comprising three electron bunches were extracted from the ATF damping ring, with bunch spacing c. 150ns. The feedback loop was closed by measuring the position of bunch 1 and correcting bunches 2 and 3. We report the performance of the feedback, including gain studies, the correction dynamic range, latency measurement, and quality of the beam position correction. The system achieved micron-level bunch stabilisation with a latency of c. 140ns.
JAI, Oxford
ATOMKI, Debrecen
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
We present the design of prototype fast beam position monitor (BPM) signal processors for use in inter-bunch beam-based feedbacks for linear colliders and electron linacs. We describe the FONT4 intra-train beam-based digital position feedback system prototype deployed at the Accelerator test facility (ATF) extraction line at KEK, Japan. The system incorporates a fast analogue beam position monitor front-end signal processor, a digital feedback board, and a fast kicker-driver amplifier. The total feedback system latency is less than 150ns, of which less than 10ns is used for the BPM processor. We report preliminary results of beam tests using electron bunches separated by c. 150ns. Position resolution of order 1 micron is obtained.
JAI, Oxford
The major goals of the final focus test beam line facility ATF2 are to provide electron beams with a few tens nanometer beam sizes and beam stability control at the nanometer level. In order to achieve such a level of stability beam based feedback systems are necessary at different timescales to correct static and dynamic effects. In particular, we present the design of intra-train feedback systems to correct the impact of fast jitter sources. We study a bunch-to-bunch feedback system to be installed at the extraction line to combat the ring extraction transverse jitters. In addition, we design a bunch-to-bunch feedback system at the interaction point for correction of position jitter due to the fast vibration of the magnets in the final focus. Optimum feedback software algorithms are discussed and simulation results are presented.
SLAC, Menlo Park, California
DESY, Hamburg
OXFORDphysics, Oxford, Oxon
ISU, Ames
CLASSE, Ithaca, New York
BNL, Upton, Long Island, New York
KEK, Ibaraki
Funding: Work supported in part by US DOE contract DE-AC02-76-SF00515.
The Interaction Region of the International Linear Collider* is based on two experimental detectors working in a push-pull mode. A time efficient implementation of this model sets specific requirements and challenges for many detector and machine systems, in particular the IR magnets, the cryogenics and the alignment system, the beamline shielding, the detector design and the overall integration. This paper attempts to separate the functional requirements of a push pull interaction region and machine detector interface from the conceptual and technical solutions being proposed by the ILC Beam Delivery Group and the three detector concepts**. As such, we hope that it provides a set of ground rules for interpreting and evaluation the MDI parts of the proposed detector concept’s Letters of Intent, due March 2009. The authors of the present paper are the leaders of the IR Integration Working Group within Global Design Effort Beam Delivery System and the representatives from each detector concept submitting the Letters Of Intent.
*ILC Reference Design Report, ILC-Report-2007-01.
**Materials of IR Engineering Design Workshop, 2007, http://www-conf.slac.stanford.edu/ireng07
SLAC, Menlo Park, California
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
JAI, Oxford
KEK, Ibaraki
IHEP Beijing, Beijing
LAL, Orsay
Royal Holloway, University of London, Surrey
IN2P3-LAPP, Annecy-le-Vieux
OXFORDphysics, Oxford, Oxon
ATOMKI, Debrecen
CERN, Geneva
DESY, Hamburg
Fermilab, Batavia
Kyungpook National University, Daegu
PAL, Pohang, Kyungbuk
Kyoto ICR, Uji, Kyoto
ICEPP, Tokyo
University of Tokyo, Tokyo
UCL, London
BNL, Upton, Long Island, New York
Tohoku University, Graduate School of Science, Sendai
UMAN, Manchester
Hiroshima University, Graduate School of Science, Higashi-Hiroshima
Cockcroft Institute, Warrington, Cheshire
ATF2 is a final-focus test beam line that attempts to focus the low-emittance beam from the ATF damping ring to a beam size of about 37 nm, and at the same time to demonstrate nm beam stability, using numerous advanced beam diagnostics and feedback tools. The construction is well advanced and beam commissioning of ATF2 has started in the second half of 2008. ATF2 is constructed and commissioned by ATF international collaborations with strong US, Asian and European participation.
