THRESHOLD VOLTAGES FOR HYPERBOLIC SECANT INVERSION PULSES

被引：5

作者：

PAYNE, GS ^{[1
]}

LEACH, MO ^{[1
]}

机构：

[1] INST CANC RES,SUTTON SM2 5PT,SURREY,ENGLAND

来源：

NMR IN BIOMEDICINE | 1992年 / 5卷 / 03期

关键词：

D O I：

10.1002/nbm.1940050307

中图分类号：

Q6 [生物物理学];

学科分类号：

071011 ;

摘要：

Spin inversion produced by hyperbolic secant RF pulses is independent of pulse amplitude once a threshold value is exceeded. A semi-empirical formula for these pulses has been derived by application of analytical solutions to the Bloch equations. This predicts the required coil voltages for inversion as a function of inversion bandwidth and side-to-width parameter-mu, based on knowledge of a reference voltage for the loaded coil. The voltage required is shown to increase linearly with bandwidth but to fall with the mu, approximately as (1/mu)0.4. Experimental confirmation is presented, and factors affecting choice of pulse parameters are discussed.

引用

页码：142 / 144

页数：3

共 4 条

[1] 2-STATE PROBLEMS INVOLVING ARBITRARY AMPLITUDE AND FREQUENCY MODULATIONS [J].