Invention Grant
- Patent Title: Refocussing pulse having an incremental phase
-
Application No.: US14780348Application Date: 2013-12-13
-
Publication No.: US10241172B2Publication Date: 2019-03-26
- Inventor: Paul Ganssle , Shriram Sarvotham
- Applicant: Halliburton Energy Services, Inc.
- Applicant Address: US TX Houston
- Assignee: Halliburton Energy Services, Inc.
- Current Assignee: Halliburton Energy Services, Inc.
- Current Assignee Address: US TX Houston
- Agency: Benjamin Fite Parker Justiss, P.C.
- International Application: PCT/US2013/075148 WO 20131213
- International Announcement: WO2015/088566 WO 20150618
- Main IPC: G01R33/50
- IPC: G01R33/50 ; G01N24/10 ; G01V3/32 ; G01N24/08 ; G01R33/54 ; G01R33/46 ; G01R33/561 ; G01R33/60

Abstract:
An example pulse sequence for performing phase coherence order selection within a single transient acquisition includes an excitation pulse with a tip angle of 90° and phase ϕA, followed by a train of N refocusing pulses with tip angles of 180°, with the center of the first refocusing pulse occurring time τ after the center of the excitation pulse, and the center of the nth refocusing pulse occurring at time (2n+1)τ after the center of the excitation pulse. This causes a train of echoes to form at times 2nt after the center of the excitation pulse. In this example, the first refocusing pulse has phase ϕB, where \ϕB−ϕA\=90°, and each successive refocusing pulse (304) has a phase ϕδ greater than the last refocusing pulse. This incremental change in pulse phase over the course of the echo train has the effect of aiabatically “dragging” the echo phase around the unit circle in a predictable manner corresponding to the phase coherence order of the relevant signals.
Public/Granted literature
- US20160054412A1 Single-Transient Phase Cycling During Spin Echo Acquisition Public/Granted day:2016-02-25
Information query