The continuous-wave saturation (CWS) behavior of several measureable parameters in an EPR spectrum of a nitroxide free radical is carried out theoretically and tested experimentally with ¹⁵N-d₁₇-4-Hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl in 60% aqueous-glycerol solutions from 273 to 340 K. The theory explicitly includes spin relaxation due to electron spin exchange and dipole–dipole interactions, but no other spectral diffusion pathways of paramagnetic relaxation. A primary objective of this work was to study the CWS of the dispersion signal induced by spin exchange and dipole–dipole interactions, a signal that is superimposed upon the absorption. This was rendered possible because, using modern least-squares fitting methods, the two signals may also be separated to high precision. Using a new rigorous theory, theoretical spectra were simulated and were also separated into absorption and dispersion components. The absorption components, both experimental and theoretical, may be analyzed using the traditional Bloch equations and compared with literature results. The dispersion components may only be analyzed by direct comparison of parameters derived from the theoretical and experimental spectra. A comparison of the amplitudes of the absorption and the dispersion components provides a severe test of the theory and the experimental results are good agreement with the theory. The experimental values of \({T}_{1}\) both from The Bloch equations and the direct comparison of the absorption components were comparable to the limited and scattered literature results where both pulsed- and CWS methods were employed. From the theory, the same value of \({T}_{1}\) was found from the CWS of the Lorentzian line width and the doubly-integrated intensity; however, there were discrepancies in the values of \({T}_{1}\) for these two parameters experimentally.

在理论上进行了氮氧自由基 EPR 光谱中几个可测量参数的连续波饱和 (CWS) 行为，并用¹⁵ N-d _{17进行了实验测试}-4-Hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl 在 273 至 340 K 的 60% 甘油水溶液中。该理论明确包括由于电子自旋交换和偶极-偶极相互作用引起的自旋弛豫，但没有其他顺磁弛豫的光谱扩散路径。这项工作的主要目的是研究由自旋交换和偶极-偶极相互作用引起的色散信号的 CWS，这是一种叠加在吸收上的信号。这之所以成为可能，是因为使用现代最小二乘拟合方法，两个信号也可以以高精度分离。使用新的严格理论，理论光谱被模拟，也被分成吸收和色散成分。吸收成分，实验和理论，可以使用传统的布洛赫方程进行分析，并与文献结果进行比较。色散分量只能通过直接比较从理论光谱和实验光谱得出的参数来分析。吸收和色散分量幅度的比较提供了对理论的严格检验，实验结果与理论吻合良好。的实验值来自 The Bloch 方程的\({T}_{1}\)和吸收分量的直接比较与使用脉冲和 CWS 方法的有限和分散的文献结果相当。从理论上，从洛伦兹线宽和双积分强度的CWS中发现了\({T}_{1}\)的相同值；但是，实验上这两个参数的\({T}_{1}\)值存在差异。