508 research outputs found
Space Flyer Unit (SFU)
The DSN (Deep Space Network) mission support requirements for the Space Flyer Unit (SFU) are summarized. The SFU is an unmanned, reusable, and retrievable free-flying platform for multipurpose use. The SFU spacecraft will carry seven individual experiments to be completed during its mission period. The mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility
Steady-State Visual Evoked Potentials Elicited from Early Visual Cortex Reflect Both Perceptual Color Space and Cone-Opponent Mechanisms
Funding Japan Society for the Promotion of Science (JSPS KAKENHI grant number JP18K13365 to S.K., JP18H04995 to I.K.) Notes S.K. was also supported by the grant from Building of Consortia for the Development of Human Resources in Science and Technology program by Japan Science and Technology Agency. S.K.A. is very grateful to Satoshi Shioiri for inviting him to Tohoku University, which enabled this collaboration. Part of this study has appeared in the form of conference proceedings (Kaneko et al. 2018). Data and codes used in this study are available at https://osf.io/m47df/.Peer reviewedPublisher PD
Super-Weyl Invariant 2D Supergravity, Anomaly and WZ Action
We present a candidate of anomaly and Wess Zumino action of the two
dimensional supergravity coupling with matters in a super-Weyl invariant
regularization. It is a generalization of the Weyl and the area preserving
\Diff invariant formulation of two dimensional gravity theory.Comment: 9 pages, Late
Fabrication of magnetometers with multiple-SQUID arrays
We have designed and fabricated magnetometers with multiple-SQUID arrays to achieve higher signal to noise ratio compared to that for a single SQUID. In our directly coupled scheme, ten SQUIDs are connected in parallel with the same pickup coil composed of four parallel rectangular loops. Each SQUID having inductance of 70 pH and junctions of 1.5 /spl mu/m width was fabricated from an Au/YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thin film on a SrTiO/sub 3/ bicrystal substrate with 30/spl deg/ misorientation angle. To avoid forming superconducting loops between junctions of adjoining SQUIDs, a Au wiring layer interrupts a current bias line. The obtained critical current of 20I/sub c/ and normal resistance of R/sub n//20 including contact resistance for the Au wiring layer are 350 /spl mu/A and 0.4 /spl Omega/, respectively. The modulation voltage of 25 /spl mu/V for multiple-SQUIDs is the same level as for a single SQUID. On the other hand, the modulation current of 40 /spl mu/A is several times larger than that for a single SQUID, but rather smaller than the expected value when all SQUIDs have equal parameters. A flux noise level of 15 /spl mu//spl Phi//sub 0//Hz/sup 1/2/ at 100 Hz, including preamplifier noise, was observed by using flux-locked loop electronics in a magnetically shielded room
Photon generation by laser-Compton scattering at the KEK-ATF
We performed a photon generation experiment by laser-Compton scattering at
the KEK-ATF, aiming to develop a Compton based polarized positron source for
linear colliders. In the experiment, laser pulses with a 357 MHz repetition
rate were accumulated and their power was enhanced by up to 250 times in the
Fabry-Perot optical resonant cavity. We succeeded in synchronizing the laser
pulses and colliding them with the 1.3 GeV electron beam in the ATF ring while
maintaining the laser pulse accumulation in the cavity. As a result, we
observed 26.0 +/- 0.1 photons per electron-laser pulse crossing, which
corresponds to a yield of 10^8 photons in a second.Comment: 3 pages, 5 figures, Preprint submitted to TIPP09 Proceedings in NIM
Nambu-Goldstone Fields, Anomalies and WZ Terms
We construct the Wess-Zumino terms from anomalies in case of quasigroups for
the following situations. One is effective gauge field theories of
Nambu-Goldstone fields associated with spontaneously broken global symmetries
and the other is anomalous gauge theories. The formalism that we will develop
can be seen as a generalization of the non-linear realization method of Lie
groups. As an example we consider 2d gravity with a Weyl invariant
regularizationComment: 19 pages, Late
- …