綱脇 惠章

It is useful to use a high-energy electron beam and a long-period wiggler to accomplish far-infrared (FIR), free-electron laser (FEL) operation with power as high as possible. In this study, the magnetic field of a wiggler has been analyzed by computational simulation and applied to the case of an FIR-FEL driven by an electron beam of the Institute of FEL (iFEL), Osaka University, with maximum energy of 165 MeV. The wiggler is a hybrid helical consisting of permanent magnets and ferromagnetic bodies and has some poles per one period used to obtain a uniform sinusoidal magnetic field. In most simulations, the period and gap length of the wiggler were assumed to be 14 and 2 cm, respectively. A uniform field higher than 1 T was calculated for the wiggler when the number of poles per period was greater than 8. It is expected by using this kind of wiggler and an electron beam energy of 165 MeV that the power of FIR-FEL will be > 100 times as high as that for a usual FEL. (C) 2003 Elsevier Science B.V. All rights reserved.

Effects of bunch length fluctuation on FEL output are studied experimentally and numerically. The FEL energy drops quasi-periodically in the saturation regime except for certain detuning. The observation of the change in bunch length reveals that the elongation of the bunch length causes these dips. A one-dimensional numerical simulation can reproduce the effect of the elongation of bunch length on the FEL output qualitatively. (C) 2003 Elsevier Science B.V. All rights reserved.

A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical, wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7 x 2.9 m(2). (C) 2003 Elsevier Science B.V. All rights reserved.

It is useful to use a high-energy electron beam and a long-period wiggler to accomplish far-infrared (FIR), free-electron laser (FEL) operation with power as high as possible. In this study, the magnetic field of a wiggler has been analyzed by computational simulation and applied to the case of an FIR-FEL driven by an electron beam of the Institute of FEL (iFEL), Osaka University, with maximum energy of 165 MeV. The wiggler is a hybrid helical consisting of permanent magnets and ferromagnetic bodies and has some poles per one period used to obtain a uniform sinusoidal magnetic field. In most simulations, the period and gap length of the wiggler were assumed to be 14 and 2 cm, respectively. A uniform field higher than 1 T was calculated for the wiggler when the number of poles per period was greater than 8. It is expected by using this kind of wiggler and an electron beam energy of 165 MeV that the power of FIR-FEL will be > 100 times as high as that for a usual FEL. (C) 2003 Elsevier Science B.V. All rights reserved.

A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical, wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7 x 2.9 m(2). (C) 2003 Elsevier Science B.V. All rights reserved.

It is useful to use a high-energy electron beam and a long-period wiggler to accomplish far-infrared (FIR), free-electron laser (FEL) operation with power as high as possible. In this study, the magnetic field of a wiggler has been analyzed by computational simulation and applied to the case of an FIR-FEL driven by an electron beam of the Institute of FEL (iFEL), Osaka University, with maximum energy of 165 MeV. The wiggler is a hybrid helical consisting of permanent magnets and ferromagnetic bodies and has some poles per one period used to obtain a uniform sinusoidal magnetic field. In most simulations, the period and gap length of the wiggler were assumed to be 14 and 2 cm, respectively. A uniform field higher than 1 T was calculated for the wiggler when the number of poles per period was greater than 8. It is expected by using this kind of wiggler and an electron beam energy of 165 MeV that the power of FIR-FEL will be > 100 times as high as that for a usual FEL. (C) 2003 Elsevier Science B.V. All rights reserved.

Effects of bunch length fluctuation on FEL output are studied experimentally and numerically. The FEL energy drops quasi-periodically in the saturation regime except for certain detuning. The observation of the change in bunch length reveals that the elongation of the bunch length causes these dips. A one-dimensional numerical simulation can reproduce the effect of the elongation of bunch length on the FEL output qualitatively. (C) 2003 Elsevier Science B.V. All rights reserved.

A compact strong test hybrid helical microwiggler has been designed and developed with ten periods, each with length 10 mm and four poles, and gap diameter of 5 mm. One period is constructed with four segments. Each segment has a thickness of 2.5 mm and consists of pentagonal permanent magnets and permendur poles. Each segment is stacked along the wiggler axis and is rotated by an angle of 90degrees to the adjacent segment. The outer width is only 72 mm. The wiggler is divided into two sections where two kinds of permanent magnet - one with apex angle of 90degrees and one with 120degrees - were installed in order to find out the effect of geometrical size for the field. Peak fields of 0.360 and 0.381 T were achieved with small rms variations of about 1.1 % and 0.6 %, respectively, depending on the geometrical size of the permanent magnet.

A compact strong test hybrid helical microwiggler has been designed and developed with ten periods, each with length 10 mm and four poles, and gap diameter of 5 mm. One period is constructed with four segments. Each segment has a thickness of 2.5 mm and consists of pentagonal permanent magnets and permendur poles. Each segment is stacked along the wiggler axis and is rotated by an angle of 90degrees to the adjacent segment. The outer width is only 72 mm. The wiggler is divided into two sections where two kinds of permanent magnet - one with apex angle of 90degrees and one with 120degrees - were installed in order to find out the effect of geometrical size for the field. Peak fields of 0.360 and 0.381 T were achieved with small rms variations of about 1.1 % and 0.6 %, respectively, depending on the geometrical size of the permanent magnet.

The development of a 100 MW far-infrared free-electron laser oscillator is reported. By using a 180 MeV electron beam, this system will provide the high power and the rapid scanning of the broad wavelength range. 10-100 mum, to enhance the user programs. The intracavity power of several GWs will be used for Compton back scattering X- or gamma-ray generation. To store such an intense radiation, the dynamics of the FEL oscillator with a coupling parameter mu(c) less than or equal to 1 which is defined as the ratio of the slippage distance and the electron bunch length, was investigated experimentally oil the operating mid-infrared system. (C) 2002 Elsevier Science B.V. All rights reserved.

The development of a 100 MW far-infrared free-electron laser oscillator is reported. By using a 180 MeV electron beam, this system will provide the high power and the rapid scanning of the broad wavelength range. 10-100 mum, to enhance the user programs. The intracavity power of several GWs will be used for Compton back scattering X- or gamma-ray generation. To store such an intense radiation, the dynamics of the FEL oscillator with a coupling parameter mu(c) less than or equal to 1 which is defined as the ratio of the slippage distance and the electron bunch length, was investigated experimentally oil the operating mid-infrared system. (C) 2002 Elsevier Science B.V. All rights reserved.

We are planning a short wavelength FEL experiment combining a micro-wiggler and an X-ray seed pulse. A micro-wiggler makes it possible to lase in the VUV to soft X-ray region using a low-energy electron beam. The development of the micro-wiggler is almost complete. With an intense X-ray seed pulse. quick start-up is expected making the wiggler length short. For the seed X-ray source we will use laser-produced Plasma. The validity of this concert was verified using a simulation code based on the SDE-method. With 10 kW X-ray power for seeding the saturation position is shortened to 5 m. (C) 2000 Published by Elsevier Science B.V. All rights reserved.

We are planning a short wavelength FEL experiment combining a micro-wiggler and an X-ray seed pulse. A micro-wiggler makes it possible to lase in the VUV to soft X-ray region using a low-energy electron beam. The development of the micro-wiggler is almost complete. With an intense X-ray seed pulse. quick start-up is expected making the wiggler length short. For the seed X-ray source we will use laser-produced Plasma. The validity of this concert was verified using a simulation code based on the SDE-method. With 10 kW X-ray power for seeding the saturation position is shortened to 5 m. (C) 2000 Published by Elsevier Science B.V. All rights reserved.

Aluminium tri-hydrogen bis (orthophosphate) monohydrate [AlH3(PO4)(2). H2O] is known as a material with a layered structure. We have synthesized the pure single phase of AlH3(PO4)(2). H2O by solvothermal reaction, with high efficiency. it was formed by the reaction of Al(OH)(3) with H3PO4 at 75 wt% : The optimum molar ratio of H3PO4 to Al(OH)(3) is 7.5. The mixture of H3PO4 and Al(OH)(3) in 1-propanol was refluxed at 94 degrees C for 24 hours under stirring. Furthermore, we intercalated phenylphosphonic acid into AlH3(PO4)(2). H2O at room temperature and obtained a material with nano-sized layers (d = 1.52 nm). Measurements of XRD and DTA-TG, and observations of SEM and TEM were made on products.

Aluminium tri-hydrogen bis (orthophosphate) monohydrate [AlH3(PO4)(2). H2O] is known as a material with a layered structure. We have synthesized the pure single phase of AlH3(PO4)(2). H2O by solvothermal reaction, with high efficiency. it was formed by the reaction of Al(OH)(3) with H3PO4 at 75 wt% : The optimum molar ratio of H3PO4 to Al(OH)(3) is 7.5. The mixture of H3PO4 and Al(OH)(3) in 1-propanol was refluxed at 94 degrees C for 24 hours under stirring. Furthermore, we intercalated phenylphosphonic acid into AlH3(PO4)(2). H2O at room temperature and obtained a material with nano-sized layers (d = 1.52 nm). Measurements of XRD and DTA-TG, and observations of SEM and TEM were made on products.

A hybrid planar wiggler with a period of 20 mm has been studied as the simplest one which gives the strong field including some higher harmonic components by selecting proper sizes of the ferromagnetic and the permanent magnet. Small gap length of the wiggler and small width of permendur satisfy these conditions to a certain degree. Gain analysis of FEL suggests that for high wiggler field of K>1 similar to 1.6, higher harmonic gains are improved primarily due to its strong field, and for low wiggler field of K<1 similar to 1.6, they are mainly due to the modification of the wiggler field distribution.