arXiv subjects

L. P. Yuan

Publications and source records attributed to L. P. Yuan.

4 recordsLinked to original sources

arXiv2020

Ultrasonic and Electromagnetic Sensors for Downhole Reservoir Characterization

The current work covers the evaluation of ultrasonic and electromagnetic (EM) techniques applied to temperature measurement and flow characterization for Enhanced Geothermal System (EGS). We have evaluated both ultrasonic techniques and microwave radiometry for temperature gradient and profile measurements. A waveguide-based ultrasonic probe was developed to measure the temperature gradient. A statistic approach on estimating the average grain size via spectral analysis of the scattered ultrasonic signals is introduced. For directional temperature measurement, different microwave antenna designs are compared numerically and an array loop antenna design is selected for further development. Finally techniques to characterize the porosity and permeability of a hot dry rock resource are presented.

physics.app-ph↗

arXiv2004

Three-body electrodisintegration of the three-nucleon bound state with $Δ$-isobar excitation: Processes below pion-production threshold

Electron scattering from the three-nucleon bound state with two- and three-body disintegration is described. The description uses the purely nucleonic charge-dependent CD-Bonn potential and its coupled-channel extension CD-Bonn + $Δ$. Exact solutions of three-particle equations are employed for the initial and final states of the reactions. The current has one-baryon and two-baryon contributions and couples nucleonic with $Δ$-isobar channels. $Δ$-isobar effects on the observables are isolated. The $Δ$-isobar excitation yields an effective three-nucleon force and effective two- and three-nucleon currents beside other $Δ$-isobar effects; they are mutually consistent.

nucl-th↗

arXiv2003

Trinucleon photonuclear reactions with $Δ$-isobar excitation: Processes below pion-production threshold

Radiative nucleon-deuteron capture and two- and three-body photo disintegration of the three-nucleon bound state are described. The description uses the purely nucleonic charge-dependent CD-Bonn potential and its coupled-channel extension CD Bonn + $Δ$. The $Δ$-isobar excitation yields an effective three-nucleon force and effective two- and three-nucleon currents besides other $Δ$-isobar effects; they are mutually consistent. Exact solutions of three-particle equations are employed for the initial and final states of the reactions. The current has one-baryon and two-baryon contributions and couples nucleonic with $Δ$-isobar channels. $Δ$-isobar effects on the observables are isolated. Shortcomings of the theoretical description are discussed and their consequence for the calculation of observables is estimated.

nucl-th↗

arXiv2002

Trinucleon Photo Reactions with $Δ$-Isobar Excitation: Radiative Nucleon-Deuteron Capture and Two-Body Photo Disintegration of the Three-Nucleon Bound State

Radiative nucleon-deuteron capture and photo disintegration of the three-nucleo n bound state with two-body final states are described. The description uses nucleon degrees of freedom extended to include the excitation of a single nucleon to a \diso. The baryonic interaction and the electromagnetic cu rrent couple nucleonic states and states with a \diso. Exact solutions of three-p article scattering equations are employed for the initial or final states of the reactions. The current has one-baryon and two-baryon contributions. The role of t he \diso in the description of the considered photo reactions is discussed and fo und to be moderate. The spin observables $A_{yy}$ and $T_{20}$ at $90^{\circ}$ la b scattering angle can be calculated model-independently from the $E1$ Siegert te rm in the long-wavelength limit.

nucl-th↗