V-Shaped Double Layers Formed by Ion Beam Reflection

1980 ◽  
Vol 45 (18) ◽  
pp. 1498-1501 ◽  
Author(s):  
R. L. Stenzel ◽  
M. Ooyama ◽  
Y. Nakamura
Keyword(s):  
Ion Beam ◽  
Double Layers ◽  
Beam Reflection

Double Layer Processes of LBMO/YBCO and Crystalline Degradations

2005 ◽  
Vol 887 ◽  
Author(s):  
Hong Zhu ◽  
Masanori Okada ◽  
Hidetaka Nakashima ◽  
Ajay K. Sarkar ◽  
Hirofumi Yamasaki ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Double Layer ◽  
Ion Beam ◽  
Double Layers ◽  
Layer Surface ◽  
Ion Beam Sputtering ◽  
Minimum Surface ◽  
Layer Deposition ◽  
Beam Sputtering

ABSTRACTDouble Layer Processes of LBMO/YBCO and Crystalline Degradations Oxide microwave devices will be widely expected in mobile communication system in the near future in the world. Superconducting YBa2Cu3Ox (YBCO) thin films are most advisable for microwave filter devices due to their very low surface resistance. Next generation devices are tunable microwave filters formed by double layers consisting of YBCO and ferromagnetic manganites such as La(Ba)MnO3 (LBMO).In order to complete excellent double layers, we must first obtain proper techniques to fabricate perfect a/c-phases of YBCO and excellent crystalline LBMO single layers on substrate at low substrate temperatures (Ts), and then fabricate their double layers. We have tried an ion beam sputtering (IBS), then now we can control the perfect a-c orientation growths of YBCO. The minimum surface roughness is 1 nm for the c-phase and 0.3 nm for the a-phase.Excellent crystalline thin films of LBMO can be grown by IBS with controlling Ts, oxygen pressure (Po) and oxygen molecular or plasma supply on MgO and LAO substrates. It can be grown down to 480 deg C. The minimum rocking half-width is 0.01 deg, and the minimum surface roughness is 0.8 nm. As-grown LBMO film shows different metal-insulator transition and Curier temperatures. The results are interpreted by a phase separation and magnetostriction.The double layers of YBCO on LBMO and LBMO on YBCO were fabricated by IBS. In YBCO/LBMO, the excellent a/c-YBCO can be grown on the underlying LBMO at 600-650 °C. The crystallinity of overlying YBCO is nearly the same with that of the single layers on MgO and LAO. The mosaicity of YBCO is much better than that of the single layers on MgO and LAO. It is noticed that the underlying LBMO crystallinity can be improved, and the mosaicity is not degraded after the double layer deposition. A n inferiority is that the double layer surface is much degraded. Then we should fabricate the smooth underlying LBMO. In LBMO/YBCO, the excellent crystalline LBMO can be grown on the underlying a/c-YBCO at 650-700 deg C. The better crystalline LBMO grows on the better crystalline YBCO. The LBMO/a-YBCO clearly shows XRD peak separations while the LBMO/c-YBCO shows peak overlappings. The crystallinity of overlying LBMO is slightly poorer that that of the single layers on LAO. The mosaicity of LBMO is much poorer than that of the single layers of LBMO on LAO, but is almost the same with that of the underlying YBCO. It should be noticed that the crystallinity of underlying YBCO is degraded considerably after the double layer deposition. Then we should deposite the overlying LBMO at low temperatures. However a superiority is that the double layer surface is not degraded or rather improved. Now we are estimating time-dependence of the crystalline degradations on the single and double layers. YBCO crystallinity is easily degraded with time but LBMO is very stable. Then LBMO/YBCO is advisable in terms of a long term degradation.

scholarly journals Dynamical behavior of U-shaped double layers: cavity formation and filamentary structures

2005 ◽  
Vol 12 (6) ◽  
pp. 783-798 ◽  
Author(s):  
N. Singh ◽  
C. Deverapalli ◽  
A. Rajagiri ◽  
I. Khazanov
Keyword(s):  
Electric Fields ◽  
Large Amplitude ◽  
Electron Beams ◽  
Ion Beam ◽  
Plasma Heating ◽  
Dynamical Behavior ◽  
Ion Beams ◽  
Double Layers ◽  
Lower Hybrid ◽  
Ps Ii

Abstract. Observations from the Polar and FAST satellites have revealed a host of intriguing features of the auroral accelerations processes in the upward current region (UCR). These features include: (i) large-amplitude parallel ( ) and perpendicular () fluctuating as well as quasi-static electric fields in density cavities, (ii) fairly large-amplitude unipolar parallel electric fields like in a strong double layer (DL), (iii) variety of wave modes, (iv) counter-streaming of upward going ion beams and downward accelerated electrons, (v) horizontally corrugated bottom region of the potential structures (PS), in which electron and ion accelerations occur, (vi) filamentary ion beams in the corrugated PS, and (vii) both upward and downward moving narrow regions of parallel electric fields, inferred from the frequency drifts of the auroral kilometric radiations. Numerical simulations of U-shaped potential structures reveal that such observed features of the UCR are integral parts of dynamically evolving auroral U-shaped potential structures. Using a 2.5-D particle-in-cell (PIC) code we simulate a U-shaped broad potentialstructure (USBPS). The dynamical behavior revealed by the simulation includes: (i) recurring redistribution of the parallel potential drop (PPD) in the PS, (ii) its up and downward motion, (iii) formation of filaments in the potential and density structures, and (iv) creation of filamentary as well as broad extended density cavities. The formation of the filamentary structures is initiated by an ion-beam driven instability of an oblique ion mode trapped inside a broad cavity, when it becomes sufficiently thin in height. The filaments of the PS create filamentary electron beams, which generate waves at frequencies above the lower hybrid frequency, affecting plasma heating. This results in plasma evacuation and formation of a cavity extended in height. The waves associated with filamentary electron beams also evolve into electron holes. The transverse and parallel scale lengths of the regions with large and as well as their magnitudes are compared with satellite data.

Observations of Short Large Amplitude Magnetic Structures at the Kronian bow shock

2020 ◽  
Author(s):  
Zsofia Bebesi ◽  
Geza Erdos ◽  
Melinda Dosa ◽  
Antal Juhasz ◽  
Karoly Szego
Keyword(s):  
Large Amplitude ◽  
Ion Beam ◽  
Plasma Heating ◽  
Bow Shock ◽  
Time Interval ◽  
Magnetic Structures ◽  
Earth Observations ◽  
Multiple Beams ◽  
Plasma Spectrometer ◽  
Beam Reflection

<p>We observed Short Large Amplitude Magnetic Structures (SLAMS) at Saturn upstream of the quasi-parallel bow shock. Cassini surveyed the quasi-parallel regime mainly during 2004 and 2005, and we present a few detailed case studies from this time interval. For our analysis we used the measurements of the Cassini Plasma Spectrometer and the Magnetometer.<br />Locally the SLAMS act as fast mode shock waves, and we observed ion beam reflection, multiple beams, deceleration and plasma heating of the solar wind protons. These features are in agreement with the near Earth observations of SLAMS. We also detected whistler precursor waves multiple times, which was also documented in studies of the Earth's foreshock region. Since the frequency of the upstream ULF waves observed at Saturn is lower than it is at Earth, it also has an effect on the spatial extension of the SLAM structures, which arise from these waves. With only one spacecraft's measurements it is not possible to study the SLAMS with the same efficiency as with the four-point measurements of the CLUSTER probes, but the basic observational features and the description of their evolutional characteristics are summarized. </p>

Ion beam reflection in a 180° bending magnet system

1988 ◽  
Vol 59 (10) ◽  
pp. 2163-2168
Author(s):  
K. Sakurai ◽  
Y. Oka ◽  
O. Kaneko ◽  
T. Kuroda
Keyword(s):  
Ion Beam ◽  
Magnet System ◽  
Beam Reflection
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