Shin-ichi Kurokawa - Academia.edu (original) (raw)

Papers by Shin-ichi Kurokawa

Proceedings Particle Accelerator Conference

Proceedings of the Ninth International Cryogenic Engineering Conference, Kobe, Japan, 11–14 May 1982, 1982

A cryogenic system of 8-GeV/c pion beam line, in which four superconducting bending magnets are i... more A cryogenic system of 8-GeV/c pion beam line, in which four superconducting bending magnets are installed, has been constructed at the KEK 12 GeV proton synchrotron and successfully operated for several months. This paper describes the components, the performance and the long term operation experience of the cryogenic system of 700W/200l/h at 4.4K.

Nuclear Instruments and Methods in Physics Research, 1983

Results are presented on the effects of radiation on BGO crystals. It is shown that BGOhasmore th... more Results are presented on the effects of radiation on BGO crystals. It is shown that BGOhasmore than two orders of magnitude higher resis-against lowenergy y rays than SF5 lead glass. Darkening of the crystal is hardly visible even after an irradiation of 3.6 x 106R. Thr: darkening faded by more than one half after several days and it has almost completely disappeared after much longer periods. Thetotem hle rate of synchrotron radiation on BGOcalorimeters is 100 R/hin aconsen ative estimate if the degradation in transrnittance is requited to be lossthan 1% over a depth of 20 radiation lengths. In BGOcalorimeters. the degradation of scintillation efficiency is less important than that of the transmittance. 99.999% pure crystals have atwo orders of magnitude better resistance Man 99.99% pure ones. Sample darkening caused by 12 GeV protons or fast neutrons is an order of magnitude more severe than that by lowenergy yrays. Moreover, the recovery is not coraplete even after aperiod of more than 100 days. Some data on sample activation are also presented.

Physical Review D, 1986

... 34, NUMBER 7 Inclusive A0 polarization in proton-nucleus collisions at 12 GeV F. Abe, K. Hara... more ... 34, NUMBER 7 Inclusive A0 polarization in proton-nucleus collisions at 12 GeV F. Abe, K. Hara,* S. Kim, K. Kondo, S. Miyashita, I. Nakano, K. Takikawa, R. Tanaka,t Y. Yamamoto, T. Yasuda,: and K. Yasuoka§ Institute of Physics, University of Tsukuba, Sakura-mura, Ibaraki 305 ...

Physical Review Letters, 1983

Physics Letters B, 1981

A measurement of direct production of electron pairs of masses below 1.3 GeV in proton-nucleus co... more A measurement of direct production of electron pairs of masses below 1.3 GeV in proton-nucleus collisions at 13 GeV/ c has been performed using a two-arm spectrometer. An enhanced low mass dielectron continuum below the p mass is observed and is discussed in terms of the mechanism of soft annihilation of partons.

Physical Review Special Topics - Accelerators and Beams, 2006

Coupled bunch instability caused by electron cloud has been observed in the KEKB-LER. Time evolut... more Coupled bunch instability caused by electron cloud has been observed in the KEKB-LER. Time evolution of the instabilities just after the turning-off the transverse bunch feedback have been recorded with several solenoid-field conditions to suppress the blowup due to electron cloud. The mode spectra of the coupled-bunch instabilities have been compaired with the simulations of electrons moving in drift space, weak solenoid field and strong bending field.

Physical Review Special Topics - Accelerators and Beams, 2005

An electron cloud induces a wake force on a charged particle beam which creates correlations betw... more An electron cloud induces a wake force on a charged particle beam which creates correlations between bunches-i.e., a small displacement of a bunch creates a perturbation of the electron cloud, which affects the motions of the following bunches, with the result that a coupled-bunch instability is caused. The coupling mode of the instability is determined by the motion of the electrons in the cloud-that is, it depends on which electrons, moving in a drift space, a weak solenoid field or a strong bending field, are dominant for the instability. We discuss the coupled-bunch instability focusing on the relation between the mode spectrum and the electron motion.

Physical Review D, 1984

... Inclusive A0 production by 12-GeV protons on nuclear targets F. Abe, K. Hara, N. Kim, K. Kond... more ... Inclusive A0 production by 12-GeV protons on nuclear targets F. Abe, K. Hara, N. Kim, K. Kondo, S. Miyashita, H. Miyata, I. Nakano, T. Sugaya, K. Takikawa, R. Tanaka,* Y. Yamamoto, T. Yasuda,t and K. Yasuokat Institute of Physics, University of Tsukuba, Sakura, Niihari, Ibaraki ...

Physical Review D, 1997

ABSTRACT

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1987

ABSTRACT Design and performance of a superconducting high energy secondary beam line, pi1, are re... more ABSTRACT Design and performance of a superconducting high energy secondary beam line, pi1, are reported. The pi1 beam line was constructed to transport an 8 GeV/c unseparated secondary beam to the experimental area of the 12 GeV proton synchrotron at KEK. The beam line has been operated for five years without any serious problems and was shut down in the summer of 1986. We describe its design, construction and operational results.

Journal of the Physical Society of Japan, 1983

Abstract The polarization of 2.4× 10 5\ varLambda 0 hyperons has been measured in inclusive produ... more Abstract The polarization of 2.4× 10 5\ varLambda 0 hyperons has been measured in inclusive production by 12-GeV protons on tungsten at three production angles, 3.5, 6.5, and 9.5. In terms of Feynman's x F and the transverse momentum p T of\ varLambda 0, the ...

Journal of the Physical Society of Japan, 1976

ABSTRACT

An electron cloud due to multipacting in the positron ring of B-factories and the damping ring of... more An electron cloud due to multipacting in the positron ring of B-factories and the damping ring of the International Linear Collider (ILC) is one of the main concerns. The electron cloud in the drift region can be suppressed by a solenoid. However, the solenoid doesn't work inside a magnet. Numerical studies show that there is strong multipacting in a dipole magnet of a B-factory positron ring. Electrons also can be trapped inside quadrupole and sextupole magnets. The electron cloud from dipole magnets and wigglers in the positron damping ring of the ILC gives a critical limitation on the choice of a circumference of the damping ring, which directly results in a choice of two 6 km rings as the baseline for the positron damping ring. Various electrodes have been studied using the program CLOUDLAND. Our studies show that a wire type of the electrode with a few hundred voltages works perfectly to kill the secondary electrons inside various magnets.

IEEE Transactions on Nuclear Science, 1981

A computer control and monitor system was constructed to handle power supplies of the beam line m... more A computer control and monitor system was constructed to handle power supplies of the beam line magnets. The interface modules are installed in CAMAC crates linked by a CAMAC serial highway. The structure and performance of the system are presented.

IEEE Transactions on Nuclear Science, 1985

The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fi... more The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fiber token ring network of twenty-four minicomputers (Hitachi HIDIC 80's) to control the TRISTAN accelerator complex, now being constructed at KEK. KEK NODAL retains main features of the original NODAL: the interpreting scheme, the multi-computer programming facility, and the data-module concept. In

IEEE Transactions on Nuclear Science, 1985

An N-toN token ring network of twenty-four minicomputers controls the TRISTAN accelerator complex... more An N-toN token ring network of twenty-four minicomputers controls the TRISTAN accelerator complex. The computers are linked by optical fiber cables with 10 Mbps transmission speed. The software system is based on the NODAL, a multi-computer interpreter language developed at CERN SPS. Typical messages exchanged between computers are NODAL programs and NODAL variables transmitted by the EXEC and the REMIT commands. These messages are exchanged as a cluster of packets whose maximum size is 512 bytes. At present, eleven minicomputers are connected to the network and the total length of the ring is 1.5 km. In this condition, the maximum attainable throughput is 980 kbytes/s. The response of a pair of an EXEC and a REMIT transactions which transmit a NODAL array A and one line of program 'REMIT A' and immediately remit the A is measured to be 95+0.0392 ms, where z is the array size in byte. In ordinary accelerator operations, the maximum channel utilization is 23. the average packet length is 96 bytes and the transmission rate is 10 kbytes/s. 2.1 FOR I=l,lO ; SET A(I)=MAG(I,'CUR') 2.2 REMIT A

IEEE Transactions on Nuclear Science, 1979

A computer control system of magnets in the low energy separated beams in KEK is reported. The sy... more A computer control system of magnets in the low energy separated beams in KEK is reported. The system consists of five CAMAC crates and a central minicomputer. The CAMAC crates are connected by a CAMAC Serial Highway, The transmission is 128 k bytes/set byte serial mode. Compared to the manual remote control arrangement, improvements in beam line operation can be identified.

IEEE Transactions on Nuclear Science, 1979

The results of the measurements of the characteristics of two low energy separated beams, K2 and ... more The results of the measurements of the characteristics of two low energy separated beams, K2 and K3, are reported. The performances of the electrostatic separators used in those beams are also presented.

Proceedings Particle Accelerator Conference

Proceedings of the Ninth International Cryogenic Engineering Conference, Kobe, Japan, 11–14 May 1982, 1982

A cryogenic system of 8-GeV/c pion beam line, in which four superconducting bending magnets are i... more A cryogenic system of 8-GeV/c pion beam line, in which four superconducting bending magnets are installed, has been constructed at the KEK 12 GeV proton synchrotron and successfully operated for several months. This paper describes the components, the performance and the long term operation experience of the cryogenic system of 700W/200l/h at 4.4K.

Nuclear Instruments and Methods in Physics Research, 1983

Results are presented on the effects of radiation on BGO crystals. It is shown that BGOhasmore th... more Results are presented on the effects of radiation on BGO crystals. It is shown that BGOhasmore than two orders of magnitude higher resis-against lowenergy y rays than SF5 lead glass. Darkening of the crystal is hardly visible even after an irradiation of 3.6 x 106R. Thr: darkening faded by more than one half after several days and it has almost completely disappeared after much longer periods. Thetotem hle rate of synchrotron radiation on BGOcalorimeters is 100 R/hin aconsen ative estimate if the degradation in transrnittance is requited to be lossthan 1% over a depth of 20 radiation lengths. In BGOcalorimeters. the degradation of scintillation efficiency is less important than that of the transmittance. 99.999% pure crystals have atwo orders of magnitude better resistance Man 99.99% pure ones. Sample darkening caused by 12 GeV protons or fast neutrons is an order of magnitude more severe than that by lowenergy yrays. Moreover, the recovery is not coraplete even after aperiod of more than 100 days. Some data on sample activation are also presented.

Physical Review D, 1986

... 34, NUMBER 7 Inclusive A0 polarization in proton-nucleus collisions at 12 GeV F. Abe, K. Hara... more ... 34, NUMBER 7 Inclusive A0 polarization in proton-nucleus collisions at 12 GeV F. Abe, K. Hara,* S. Kim, K. Kondo, S. Miyashita, I. Nakano, K. Takikawa, R. Tanaka,t Y. Yamamoto, T. Yasuda,: and K. Yasuoka§ Institute of Physics, University of Tsukuba, Sakura-mura, Ibaraki 305 ...

Physical Review Letters, 1983

Physics Letters B, 1981

A measurement of direct production of electron pairs of masses below 1.3 GeV in proton-nucleus co... more A measurement of direct production of electron pairs of masses below 1.3 GeV in proton-nucleus collisions at 13 GeV/ c has been performed using a two-arm spectrometer. An enhanced low mass dielectron continuum below the p mass is observed and is discussed in terms of the mechanism of soft annihilation of partons.

Physical Review Special Topics - Accelerators and Beams, 2006

Coupled bunch instability caused by electron cloud has been observed in the KEKB-LER. Time evolut... more Coupled bunch instability caused by electron cloud has been observed in the KEKB-LER. Time evolution of the instabilities just after the turning-off the transverse bunch feedback have been recorded with several solenoid-field conditions to suppress the blowup due to electron cloud. The mode spectra of the coupled-bunch instabilities have been compaired with the simulations of electrons moving in drift space, weak solenoid field and strong bending field.

Physical Review Special Topics - Accelerators and Beams, 2005

An electron cloud induces a wake force on a charged particle beam which creates correlations betw... more An electron cloud induces a wake force on a charged particle beam which creates correlations between bunches-i.e., a small displacement of a bunch creates a perturbation of the electron cloud, which affects the motions of the following bunches, with the result that a coupled-bunch instability is caused. The coupling mode of the instability is determined by the motion of the electrons in the cloud-that is, it depends on which electrons, moving in a drift space, a weak solenoid field or a strong bending field, are dominant for the instability. We discuss the coupled-bunch instability focusing on the relation between the mode spectrum and the electron motion.

Physical Review D, 1984

... Inclusive A0 production by 12-GeV protons on nuclear targets F. Abe, K. Hara, N. Kim, K. Kond... more ... Inclusive A0 production by 12-GeV protons on nuclear targets F. Abe, K. Hara, N. Kim, K. Kondo, S. Miyashita, H. Miyata, I. Nakano, T. Sugaya, K. Takikawa, R. Tanaka,* Y. Yamamoto, T. Yasuda,t and K. Yasuokat Institute of Physics, University of Tsukuba, Sakura, Niihari, Ibaraki ...

Physical Review D, 1997

ABSTRACT

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1987

ABSTRACT Design and performance of a superconducting high energy secondary beam line, pi1, are re... more ABSTRACT Design and performance of a superconducting high energy secondary beam line, pi1, are reported. The pi1 beam line was constructed to transport an 8 GeV/c unseparated secondary beam to the experimental area of the 12 GeV proton synchrotron at KEK. The beam line has been operated for five years without any serious problems and was shut down in the summer of 1986. We describe its design, construction and operational results.

Journal of the Physical Society of Japan, 1983

Abstract The polarization of 2.4× 10 5\ varLambda 0 hyperons has been measured in inclusive produ... more Abstract The polarization of 2.4× 10 5\ varLambda 0 hyperons has been measured in inclusive production by 12-GeV protons on tungsten at three production angles, 3.5, 6.5, and 9.5. In terms of Feynman's x F and the transverse momentum p T of\ varLambda 0, the ...

Journal of the Physical Society of Japan, 1976

ABSTRACT

An electron cloud due to multipacting in the positron ring of B-factories and the damping ring of... more An electron cloud due to multipacting in the positron ring of B-factories and the damping ring of the International Linear Collider (ILC) is one of the main concerns. The electron cloud in the drift region can be suppressed by a solenoid. However, the solenoid doesn't work inside a magnet. Numerical studies show that there is strong multipacting in a dipole magnet of a B-factory positron ring. Electrons also can be trapped inside quadrupole and sextupole magnets. The electron cloud from dipole magnets and wigglers in the positron damping ring of the ILC gives a critical limitation on the choice of a circumference of the damping ring, which directly results in a choice of two 6 km rings as the baseline for the positron damping ring. Various electrodes have been studied using the program CLOUDLAND. Our studies show that a wire type of the electrode with a few hundred voltages works perfectly to kill the secondary electrons inside various magnets.

IEEE Transactions on Nuclear Science, 1981

A computer control and monitor system was constructed to handle power supplies of the beam line m... more A computer control and monitor system was constructed to handle power supplies of the beam line magnets. The interface modules are installed in CAMAC crates linked by a CAMAC serial highway. The structure and performance of the system are presented.

IEEE Transactions on Nuclear Science, 1985

The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fi... more The KEK NODAL system, which is based on the NODAL devised at the CERN SPS, works on an optical-fiber token ring network of twenty-four minicomputers (Hitachi HIDIC 80's) to control the TRISTAN accelerator complex, now being constructed at KEK. KEK NODAL retains main features of the original NODAL: the interpreting scheme, the multi-computer programming facility, and the data-module concept. In

IEEE Transactions on Nuclear Science, 1985

An N-toN token ring network of twenty-four minicomputers controls the TRISTAN accelerator complex... more An N-toN token ring network of twenty-four minicomputers controls the TRISTAN accelerator complex. The computers are linked by optical fiber cables with 10 Mbps transmission speed. The software system is based on the NODAL, a multi-computer interpreter language developed at CERN SPS. Typical messages exchanged between computers are NODAL programs and NODAL variables transmitted by the EXEC and the REMIT commands. These messages are exchanged as a cluster of packets whose maximum size is 512 bytes. At present, eleven minicomputers are connected to the network and the total length of the ring is 1.5 km. In this condition, the maximum attainable throughput is 980 kbytes/s. The response of a pair of an EXEC and a REMIT transactions which transmit a NODAL array A and one line of program 'REMIT A' and immediately remit the A is measured to be 95+0.0392 ms, where z is the array size in byte. In ordinary accelerator operations, the maximum channel utilization is 23. the average packet length is 96 bytes and the transmission rate is 10 kbytes/s. 2.1 FOR I=l,lO ; SET A(I)=MAG(I,'CUR') 2.2 REMIT A

IEEE Transactions on Nuclear Science, 1979

A computer control system of magnets in the low energy separated beams in KEK is reported. The sy... more A computer control system of magnets in the low energy separated beams in KEK is reported. The system consists of five CAMAC crates and a central minicomputer. The CAMAC crates are connected by a CAMAC Serial Highway, The transmission is 128 k bytes/set byte serial mode. Compared to the manual remote control arrangement, improvements in beam line operation can be identified.

IEEE Transactions on Nuclear Science, 1979

The results of the measurements of the characteristics of two low energy separated beams, K2 and ... more The results of the measurements of the characteristics of two low energy separated beams, K2 and K3, are reported. The performances of the electrostatic separators used in those beams are also presented.