Study on modulation amplitude stabilization method for PEM based on FPGA in atomic magnetometer

2017 ◽  
Author(s):  
Qinghua Wang ◽  
Wei Quan ◽  
Lihong Duan
Keyword(s):  
Modulation Amplitude ◽  
Stabilization Method ◽  
Amplitude Stabilization

Experimental Verification of Stabilization Method for Residential DC System Based on Passivity Criterion

2017 ◽  
Vol 137 (8) ◽  
pp. 631-638 ◽  
Author(s):  
Hiroki Yamano ◽  
Koji Takechi ◽  
Hiroaki Kakigano ◽  
Makoto Ohashi
Keyword(s):  
Experimental Verification ◽  
Stabilization Method ◽  
Dc System

scholarly journals The Genuine Resonance of Full-Charm Tetraquarks

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 155
Author(s):  
Xiaoyun Chen
Keyword(s):  
Quark Model ◽  
Bound States ◽  
Expansion Method ◽  
Chiral Quark Model ◽  
Stabilization Method ◽  
Scaling Method ◽  
Resonance States ◽  
Gaussian Expansion Method ◽  
Color Structure ◽  
Quantum Numbers

In this work, the genuine resonance states of full-charm tetraquark systems with quantum numbers JPC=0++,1+−,2++ are searched in a nonrelativistic chiral quark model with the help of the Gaussian Expansion Method. In this calculation, two structures, meson-meson and diquark–antidiquark, as well as their mixing with all possible color-spin configurations, are considered. The results show that no bound states can be formed. However, resonances are possible because of the color structure. The genuine resonances are identified by the stabilization method (real scaling method). Several resonances for the full-charm system are proposed, and some of them are reasonable candidates for the full-charm states recently reported by LHCb.

scholarly journals A NuSTAR confirmation of the 36 ks hard X-ray pulse-phase modulation in the magnetar 1E 1547.0 − 5408

2021 ◽  
Vol 502 (2) ◽  
pp. 2266-2284
Author(s):  
Kazuo Makishima ◽  
Teruaki Enoto ◽  
Hiroki Yoneda ◽  
Hirokazu Odaka
Keyword(s):  
Time Lapse ◽  
Phase Behaviour ◽  
Modulation Amplitude ◽  
Axial Deformation ◽  
Physical Processes ◽  
Arrival Times ◽  
Pulse Phase ◽  
Phase Variations ◽  
Complex Phenomena ◽  
Made In

ABSTRACT This paper describes an analysis of the NuSTAR data of the fastest-rotating magnetar 1E 1547 − 5408, acquired in 2016 April for a time lapse of 151 ks. The source was detected with a 1–60 keV flux of 1.7 × 10−11 erg s−1 cm−2, and its pulsation at a period of 2.086710(5) s. In 8–25 keV, the pulses were phase-modulated with a period of T = 36.0 ± 2.3 ks, and an amplitude of ∼0.2 s. This reconfirms the Suzaku discovery of the same effect at $T=36.0 ^{+4.5}_{-2.5}$ ks, made in the 2009 outburst. These results strengthen the view derived from the Suzaku data, that this magnetar performs free precession as a result of its axial deformation by ∼0.6 × 10−4, possibly caused by internal toroidal magneti fields (MFs) reaching ∼1016 G. Like in the Suzaku case, the modulation was not detected in energies below ∼8 keV. Above 10 keV, the pulse-phase behaviour, including the 36 ks modulation parameters, exhibited complex energy dependencies: at ∼22 keV, the modulation amplitude increased to ∼0.5 s, and the modulation phase changed by ∼65° over 10–27 keV, followed by a phase reversal. Although the pulse significance and pulsed fraction were originally very low in >10 keV, they both increased noticeably, when the arrival times of individual photons were corrected for these systematic pulse-phase variations. Possible origins of these complex phenomena are discussed, in terms of several physical processes that are specific to ultrastrong MFs.

Tuning Characteristics of DFB Diode Laser and its Application to TDLAS Gas Sensor Design

2014 ◽  
Vol 511-512 ◽  
pp. 173-177 ◽  
Author(s):  
Rong Jun Lu ◽  
De Ming Shen ◽  
Qian Qian Du ◽  
Bao Zhen Huang ◽  
Jian Shu Shi
Keyword(s):  
Diode Lasers ◽  
Modulation Amplitude ◽  
Wavelength Modulation ◽  
Modulation Spectroscopy ◽  
Dynamic Tuning ◽  
Harmonic Components ◽  
Laser Devices ◽  
Current Tuning ◽  
Temperature Dynamic ◽  
Sweep Speed

Static and dynamic tuning characteristics of Distribute Feedback (DFB) diode lasers are investigated with practical laser devices. These characteristics are the basic guidelines for practical TDLAS sensors design. Static tuning characteristics help to select suitable diode lasers from limited available laser devices with specific wavelength and to set an appropriate working current and temperature. Dynamic tuning characteristics decide the sweep speed of current slope in both direct absorb Spectroscopy (DAS) and wavelength modulation Spectroscopy (WMS). Because of nonlinearity in the relation between wavelength and tuning current, the measured spectral line position should be corrected by the dynamic characteristics. For WMS, current tuning efficient and IM/AM (Intense modulation/Amplitude modulation) differential phase could be utilized to optimize laser modulation and harmonic components demodulation.

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