Strategy and Management of Network Security at KEK

Recently the troubles related to the network security have often occurred attacks.It consists of two fundamental thinge;the monitoring and the access control.To monitor the network,we have installed the intrusion detectioin system and have managed it since 1998,For the second thing,we arranged three categories to classify all hosts (about 5000 hosts) at KEK according to their security level.To realize these three categories,we filter the incoming packet from outside KEK whether it has a SYN flag or not.The network monitoring and the access control produced good effects in keeping our security level high.Since 2000 we have started the transiton of LAN from shared-media network to switched network.Now almost part of LAN was re-configured and in this new LAN 10Mbps/100Mbps/1Gbps Ethernet are supported.Currently we are planning further speedup(10Gbps)and redundancy of network.Not only LAN but also WAN,network speed will be upgraded to 10 Gbps thanks to the strong promotion of IT by Japanese government,In this very high speed network,our current strategy will be affected and again the network security becomes a big issue,This paper describes our experiences in practice of the current strategy and management know-how together with the discussion on the new strategy.     

Propagation of a beam halo in accelerator test facility 2 at KEK

The beam halo is a major issue for interaction region (IR) backgrounds at many colliders, for example, future linear colliders, B factories, and also it is an important problem at ATF2. In this paper, we report on the halo propagation along the ATF2 beam line with realistic apertures, the nonlinear optics influence on the increasing number of halo particles input is analyzed, and the transmitted halo particles distribution just before the last BPM is then described, the results from which will benefit the Compton recoil electrons measurement.     

Nuclear Resonant scattering experiments with synchrotron radiation at KEK

Experiments of nuclear Resonant scattering carried out at PF and TRISTAN-AR of KEK are described, which include nuclear Bragg scattering in time domain as well as energy domain, time-resolved nuclear resonant forward scattering, and interferometric studies.     

Simulation of beam size multiknobs correction at the Accelerator Test Facility 2 at KEK

The ATF2 project is the final focus system prototype for the ILC and CLIC linear collider projects, with a purpose of reaching a 37 nm vertical beam size at the interaction point (IP). During the initial commissioning, we started with larger-than-nominal β-functions at the IP in order to reduce the effects from higher-order optical aberrations and thereby simplifying the optical corrections needed. We report on the simulation studies at two different IP locations developed based on waist scan, dispersion, coupling and β function multiknobs correction in the large β optics of ATF2, in the presence of two kinds of magnet inaccuracies (quadrupole gradient and roll errors) to generate all possible linear optic distortions at the IP. A vertical beam size which is very close to the nominal beam size is obtained based on the simulation study.     

Consequences of a dual resonance exclusive Kernel for hadronic correlations

The exclusive kernel of a previously proposed integral equation (IE) is expressed in terms of DRM amplitudes in the central region. The $\text{|}\text{B}{}_6\text{B}{}_5\text{|}$ relative normalization is fitted to four-prong NAL data. The IE is then solved numerically to compute the inclusive correlated density R_cc(y). It is also predicted that R_+?:R₊₊:R_{__} = f?_rmc: ?₊:?_{_}, f ≈ 2, at y = 0.     

Simulation of beam size multiknobs correction at the Accelerator Test Facility 2 at KEK

The ATF2 project is the final focus system prototype for the ILC and CLIC linear collider projects, with a purpose of reaching a 37 nm vertical beam size at the interaction point (IP). During the initial com- missioning, we started with larger-than-nominal β-functions at the IP in order to reduce the effects from higher-order optical aberrations and thereby simplifying the optical corrections needed. We report on the simulation studies at two different IP locations developed based on waist scan, dispersion, coupling and β func- tion multiknobs correction in the large β optics of ATF2, in the presence of two kinds of magnet inaccuracies (quadrupote gradient and roll errors) to generate all possible linear optic distortions at the IP. A vertical beam size which is very close to the nominal beam size is obtained based on the simulation study.     

Extremely low vertical-emittance beam in the accelerator test facility at KEK

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.     

Beam-size measurement with optical diffraction radiation at KEK accelerator test facility

An experiment on the investigation of optical diffraction radiation (ODR) from a slit target as a possible tool for noninvasive electron beam-size diagnostics has been performed at the KEK accelerator test facility. The experimental setup has been installed at the diagnostics section of the extraction line. We have performed the first incoherent ODR observation from a slit target. The measured angular distributions are in reasonable agreement with the theoretical expectation. The beam-size effect onto the ODR angular pattern has been observed. Moreover, the sensitivity to the beam size as small as 14 microm has been achieved.     

A beam test of prototype time projection chamber using micro-pattern gas detectors at KEK

We conducted a series of beam tests of prototype TPCs for the international linear collider (ILC) experiment, equipped with an MWPC, a MicroMEGAS, or GEMs as a readout device. The prototype operated successfully in a test beam at KEK under an axial magnetic field of up to 1 T. The analysis of data is now in progress and some of the preliminary results obtained with GEMs and MicroMEGAS are presented along with our interpretation. Also given is the extrapolation of the obtained spatial resolution to that of a large TPC expected as the central tracker of the ILC experiment. on behalf of part of the ILC-TPC Collaboration     

Review of the Elementary Particles Physics in the External Electromagnetic Fields Studies at KEK

Russian Physics Journal - High Energy Accelerator Research Organization (KEK [1]) is a world class accelerator-based research laboratory. The field of its scientific interests spreads widely from...