Recent results at the Slow Positron Facility (SPF), Institute of Materials Structure Science (IMSS), KEK are reported. Studies using the total-reflection high-energy positron diffraction (TRHEPD) ...station revealed the structures of rutile-TiO2(110) (1×2), graphene on Cu (111) and Co (0001), and germanene on Al (111). First observations of the shape resonance in the Ps− photodetachment process were made using the positronium negative ion (Ps−) station. Experiments using the positronium time-of-flight (Ps-TOF) station showed significant enhancement of the Ps formation efficiency and the energy loss in the Ps formation-emission process. A pulse-stretching section has been implemented, which stretches the positron pulse width from 1.2 μs up to almost 20 ms.
The interaction region of KEKB Kanazawa, K.; Nakayama, H.; Ogitsu, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2003, Letnik:
499, Številka:
1
Journal Article
Recenzirano
An asymmetric-energy collider of
8
GeV
electrons and
3.5
GeV
positrons, KEKB, has been operating at KEK since 1998. On July 9, 2001 it achieved the highest record of luminosity,
4.5×10
33
cm
−2
s
−1
.... This paper describes the interaction region (IR) extending about
8
m
from the interaction point (IP) along each beam direction. The main machine components in the IR are focusing quadrupole magnets, compensation solenoids, and vacuum chambers, which are positioned on movable stages. They are designed to focus both beams into collisions with a finite angle crossing.
Evaluation of extremely small horizontal emittance Okugi, T.; Hirose, T.; Hayano, H. ...
Physical review special topics. PRST-AB. Accelerators and beams,
02/1999, Letnik:
2, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The KEK Accelerator Test Facility (KEK-ATF) was constructed to develop technologies for producing a low-emittance beam which will be required by future linear colliders. The KEK-ATF consists of an ...injector linac, a damping ring, and a beam extraction line. The basic optical structure of the damping ring is a FOBO lattice, which reduces the horizontal dispersion at the center of the bending magnets and, as a consequence, can produce an extremely small emittance beam. To verify the performance of such a unique, low-emittance lattice, it is crucial to measure the horizontal emittance. The horizontal emittance was measured using wire scanners in the beam extraction line. Since the horizontal beam position was not stable, we established a method to correct the measured beam size for position fluctuation (“jitter”) and we succeeded in the observation of the so far smallest horizontal emittance in any accelerator. The measured horizontal emittance was 1.37±0.03nm at a beam energy of 1.285 GeV and a bunch population of \(3–5\)×10^{9}, in agreement with the design value of 1.27–1.34 nm at the beam energy and the bunch population.
A superconducting final focus magnet system for the interaction region of KEKB was constructed. It consists of two solenoid field compensation magnets and two superconducting quadrupoles with three ...kinds of correction coils. The system test has been successfully completed. This paper describes the design, construction and the test results of these magnets.
The Barrel CRID detector has been operating successfully at SLD for the past seven years. It is an important tool for SLD physics analyses. We report results based on long term operational experience ...of a number of important quantities such as the Cherenkov quality factor, N/sub 0/ of the device, fluid transparency, electron lifetime, single electron detection efficiency, anode wire ageing, TMAE purity, long term transparency, Cherenkov angle resolution and the number of photoelectrons observed per ring.
The endcap Cherenkov ring imaging detector at SLD Abe, K.; Antilogus, P.; Aston, D. ...
IEEE transactions on nuclear science,
08/1995, Letnik:
42, Številka:
4
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
We present the Cherenkov ring imaging detector in the endcap regions of the SLD detector and report initial performance. The endcap CRID was completed and commissioned in 1993 and is fully ...operational for the 1994 run. First Cherenkov rings have been observed. The endcap CRID detectors and fluid systems are described and initial operational experience is discussed.< >
Results from the SLD barrel CRID detector Abe, K.; Antilogus, P.; Aston, D. ...
IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States),
08/1994, Letnik:
41, Številka:
4
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
We report on operational experience with and experimental performance of the SLD barrel Cherenkov Ring Imaging Detector from the 1992 and 1993 physics runs. The liquid (C/sub 6/F/sub 14/) and gas ...(C/sub 5/F/sub 12/) radiator recirculation systems have performed well, and the drift gas supply system has operated successfully with TMAE for three years. Cherenkov rings have been observed from both the liquid and gas radiators. The number and angular resolution of Cherenkov photons have been measured, and found to be close to design specifications.< >
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