Noriichi Kanaya

Synchrotron radiation beamline to study radioactive materials at the Photon factory

Abstract Design and construction of a new beamline have been described. The beamline is housed in a specially designed area controlled for radioactive materials at the Photon Factory (PF) in the National Laboratory for High Energy Physics (KEK). The beamline system consists of a front-end and two branchlines. One of the branchlines is used for X-ray photoelectron spectroscopy and radiation biology in the energy range of 1.8-6 keV and the other for X-ray diffractometry and XAFS studies as well as radiation biology in the range of 4–20 keV. The former was particularly equipped for the protection against accidental scattering of radioactive materials both inside and outside of the vacuum system.

Reconstruction for the brilliance-upgrading project of the Photon Factory storage ring

Reconstruction of the Photon Factory storage ring (PF ring; 2.5 GeV) is now in progress to provide very brilliant synchrotron radiation to users, i.e. the emittance is being reduced by a factor of five. Components, such as the quadrupole and sextupole magnets, vacuum chambers, beamlines and beam-position monitors, are being replaced by new ones in 16 normal-cell sections of the PF ring. The accelerating cavities, injection systems and control systems are also being replaced. Operation will commence when the improvements are completed on 1 October 1997.

Vacuum protection system using an interlocked fast-closing valve for a high-power wiggler beam line

The finite-element method was used to calculate a rise in temperature at a fast-closing valve (FCV) blade during exposure to intense synchrotron radiation from a 53-pole wiggler at the 2.5-GeV Photon Factory storage ring. The results indicate a possible meltdown of the titanium-alloy blade within 0.1 s at a maximum beam current of 500 mA, making the vacuum protection function of the FCV ineffective for an instantaneous vacuum failure downstream of the wiggler beam line. In order to prevent the blade from melting, the FCV control system has been interlocked with RF klystrons so as to initiate blade closure after dumping the electron beam by turning off the RF power. Performance tests have shown that the system could dump the electron beam within 95 mu s and then close the blade within 12.4 ms after being triggered. >

Pneumatic fast-closing valve for synchrotron radiation beam lines at the photon factory

A fast-closing valve system has been designed and fabricated in order to protect the vacuum of the synchrotron radiation beam line and that of the 2.5 GeV storage ring from a sudden vacuum failure at the downstream end of the beam line. Upon the detection of a failure the valve closes within 11.9 ms by pneumatic pressure on a drive piston in a cylinder. Within the last 3.7 ms of the closing time the downward movement of the blade is decelerated so as to reduce the closing shock. A hard TiN ceramic membrane is coated on the surface of the titanium blade. On the surface of a stainless steel aperture, an Al/sub 2/O/sub 3/-TiO/sub 2/ ceramic membrane (less hard than TiN) is coated in order to attain low conductance and smooth movement of the blade. This ensures a low leak rate of 0.135 torr l/s and a long life cycle of the mechanism (more than 8000 times). >

Pneumatically-Driven Fast Closing Valve System for Synchrotron Radiation Sources

A fast closing valve (FCV) system has been built to protect the vacuum of the electron storage ring against sudden vacuum failures during synchrotron radiation experiments. An electronic control detects the failure, and closes a 140 × 17 mm aperture within 32 ms with a guillotine blade driven by pneumatic pressure. This pressure is gated by a magnetic valve which is operated by an explosive charge from a capacitor bank. The design of the FCV itself is very simple; it is operated directly by a single pneumatic piston. The FCV system has a long operating lifetime and the blade can be readily rearmed in 0.5 s.

Design and performance of beamline BL-8 at the photon factory

Abstract We designed and constructed beamline BL-8 at the Photon Factory, the National Laboratory for High Energy Physics. The beamline has been in full operation since 1987–1988. On this beamline, one can utilize the synchrotron radiation from a bending magnet in the 40 eV to 35 keV energy range. The beamline has three branch beamlines (8A, 8B, and 8C) where one can perform a wide scope of researches: e.g., soft X-ray spectroscopy and photochemical reactions on 8A; XAFS on 8B; lithography, microscopy, and micro-tomography on 8C.

Beryllium window assembly for the 53‐pole wiggler beamline at the Photon Factory

The performance of a beryllium window assembly which is exposed to large heat loads due to intense photon flux form a 53‐pole multipole wiggler is described. Six graphite foils were designed to have a thickness of 0.14 mm each in order to reduce the thermal loads at two 0.2‐mm‐thick beryllium windows so that the beryllium windows could withstand the high thermal stress caused by a peak power density of 3.2 kW/mrad2 from the wiggler. The beryllium windows are located at the downstream side of the graphite foils and transmit x‐ray components to an experimental station. The maximum temperature rise measured at the beryllium windows under a total synchrotron radiation power of 7.75 kW at 300 mA of stored beam current was 180 °C. No visual damage was observed.

A vertical wiggler beamline and a dual purpose beam port for mirror tests and infrared spectroscopy

Abstract The front end of a vertical wiggler beamline which accepts a 9 mrad vertical divergence of radiation emitted from a superconducting wiggler is described. Components of the front end were designed to withstand a heat load of 200 W/mrad at 2.5 GeV and 500 mA operation of the vertical wiggler. The main features of a dual purpose beam port are presented.

Distributed control system using a remote distributed object model for 1.8-GeV synchrotron radiation beamlines at TSRF

A distributed control system has been developed to control synchrotron radiation beamlines for the 1.8-GeV storage ring at Tohoku Synchrotron Radiation Facility (TSRF), Tohoku University, which has 50 beamlines for soft X-ray optics/microscopy, lithography, and biomaterial research. The system is composed of outlying nodes and remote operator consoles connected to a network. Each beamline is controlled by its own outlying node independently of adjacent beamlines in accordance with physics experimental requirements. The control system protects ultra-high vacuum components of the beamline and the storage ring by closing valves/shutters upon detecting a vacuum failure. The system was implemented using a distributed object model, Java remote method invocation (RMI). The control system provides information on the operation of the beamlines to remote clients such as operator consoles over the network in order to operate the TSRF. The design and implementation of the distributed control system as well as the control scheme for the synchrotron radiation beamlines at TSRF are described in this paper.

Vacuum-pump control system using programmable logic controllers on the TCP/IP network for the 2.5-GeV storage ring

A vacuum-pump control system has been developed using programmable-logic controllers (PLC) for the 2.5-GeV storage ring at the Photon Factory, High Energy Accelerator Research Organization (KEK). There are sixty-six Ti-getter vacuum pumps at the storage ring. Evacuation of gases in the storage ring is done by controlling the current in the titanium filaments in the vacuum pump (max 50 A). A PLC has a TCP/IP network port, 16-bit-digital output ports connected to sixteen solid-state relays (SSR) for current control. The PLC can simultaneously control up to sixteen pumps. These vacuum pumps are connected to SSRs which chop the AC current so as to control the current in the pumps. To operate the pumps, the pump current must have a trapezoidal-shaped current form. The PLC is configured so that the current in the pumps has a trapezoidal form associated with pre-heating, evacuation, and cooling-down phases of the pump. PLCs are connected to a personal computer (PC) through the network. The PC can automatically control the PLCs by sending a set of commands through the TCP/IP network. The commands specify the duration of the current form. Upon receiving a command from a PC running under WindowsNT through the network, the PLC generates pulse-trains through the digital output ports to trigger the SSRs in association with the operating phases. The design of the vacuum-pump control system is discussed.