WorldCat Identities

Wake, Masayoshi

Works: 10 works in 13 publications in 2 languages and 34 library holdings
Roles: Author
Publication Timeline
Most widely held works by Masayoshi Wake
A test of a 2 Tesla superconducting transmission line magnet system( )

1 edition published in 2005 in English and held by 5 WorldCat member libraries worldwide

Superconducting transmission line magnet test system for an injector accelerator of a staged VLHC proton-proton colliding beam accelerator has been built and operated at Fermilab. The 1.5 m long, twin-aperture, combined function dipole magnet of 2 Tesla field is excited by a single turn 100 kA transmission line superconductor. The 100 kA dc current is generated using dc-dc switching converters powered by a bulk 240 kW supply. A pair of horizontally placed conventional leads facilitates transfer of this current to the magnet transmission line superconductor operating at liquid helium temperature. Fabrication of magnet components and magnet assembly work are described. The magnet test system and its operation are presented, and the performance is summarized
Three dimensional FEM quench simulations of superconducting strands( )

1 edition published in 2005 in English and held by 5 WorldCat member libraries worldwide

The detailed phenomena in quench starting of Nb{sub 3}Sn strands are simulated in 3-D and in time using ANSYS and FEMLAB programs. The current sharing between the superconductor and copper stabilizer in strands at the beginning of a quench was studied and displayed in time. The differences in copper configuration and RRR value of copper were found to have large effect to the stability and quench propagation velocity. The MPZ theory was found to be effective for 3D multifilament situation
Quench problems of Nb3 Sn cosine theta high field dipole model magnets( )

1 edition published in 2004 in English and held by 5 WorldCat member libraries worldwide

We have developed and tested several cosine theta high field dipole model magnets for accelerator application, utilizing Nb{sub 3}Sn strands made by MJR method and PIT method. With Rutherford cables made with PIT strand we achieved 10.1 Tesla central field at 2.2 K operation, and 9.5 Tesla at 4.5 K operation. The magnet wound with the MJR cable prematurely quenched at 6.8 Tesla at 4.5 K due to cryo-instability. Typical quench behaviors of these magnets are described for both types of magnets, HFDA-04 of MJR and HFDA-05 of PIT. Their characteristics parameters are compared on d{sub eff}, RRR, thermal conductivity and others, together with other historical Nb{sub 3}Sn magnets. It is suggested a larger RRR value is essential for the stability of the epoxy impregnated high field magnets made with high current density strands. It is shown that a magnet with a larger RRR value has a longer MPZ value and more stable, due to its high thermal conductivity and low resistivity
Magnetization anomaly of Nb3Al strands and instability of Nb3Al Rutherford cables( )

1 edition published in 2006 in English and held by 5 WorldCat member libraries worldwide

Using a Cu stabilized Nb{sub 3}Al strand with Nb matrix, a 30 meter long Nb{sub 3}Al Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this Nb{sub 3}Al strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual B{sub c2} {approx} 0.5 Tesla (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. As a possible explanation for this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands is suggested. The instability problem observed in low field tests of the Nb{sub 3}Al Rutherford cables is attributed to this effect
The 100 kA current leads for a superconducting transmission line magnet( )

1 edition published in 2005 in English and held by 5 WorldCat member libraries worldwide

A pair of current leads to power a transmission line magnet cooled at liquid helium temperature has been designed and developed at Fermilab. The leads designed to carry 100 kA dc current. Each lead consists of a warm end, heat exchange section and a cold end. The warm end is a half moon plate and cylinder brazed together. The heat exchange section is made of 202 copper rods arranged in a staggered pattern. Each rod is 6.35 mm in diameter and 1650 mm in length. The rods were soft-soldered into 12.7 mm deep holes at both warm and cold ends. The helium gas flow, guided by anodized aluminum baffles along the lead length, allows for a relatively high heat transfer coefficient between the current carrying rods and cooling helium gas. As a result the current leads were successfully tested with a ramping current of up to 104 kA. The current lead design, assembly work and the test results are presented
Magnetization measurement of niobium for superconducting cavity material evaluation by Masayoshi Wake( Book )

2 editions published in 1995 in English and held by 3 WorldCat member libraries worldwide

Jifuteria yobo sesshuka jiken : Sengoshi no yami to kodomotachi by Katsuhito Tainaka( Book )

2 editions published in 2012 in Japanese and held by 3 WorldCat member libraries worldwide

Spectrographic detection of nitrogen impurity in helium by Katsuhiro Mimori( Book )

2 editions published in 1987 in Japanese and held by 3 WorldCat member libraries worldwide

Magnetization measurement of niobium for superconductingcavity material evaluation( Book )

1 edition published in 1995 in English and held by 0 WorldCat member libraries worldwide

Audience Level
Audience Level
  Kids General Special  
Audience level: 0.83 (from 0.81 for A test of ... to 1.00 for RRR evalua ...)

Alternative Names
Wake, Masayoshi, 1947-

ワケ, マサヨシ, 1947-