W-band frequency-swept EPR.
W-band frequency-swept EPR.
复制标题
DOI：
10.1016/j.jmr.2010.04.005
复制
发表时间：
2010-07
期刊：
影响因子：
--
通讯作者：
Froncisz W
中科院分区：
文献类型：
--
作者：
Hyde JS;Strangeway RA;Camenisch TG;Ratke JJ;Froncisz W
本文描述了一种新的实验氮氧自由基自旋标记使用多臂EPR W带桥与环隙谐振器（LGR）。我们证明了EPR光谱的自旋标记的线性扫描的微波频率在整个频谱。LGR的高带宽（在微波谐振的3 dB点之间约为1 GHz）使这项新实验成为可能。频率可调的钇铁石榴石（YIG）振荡器提供高达1.8 × 105 GHz/s的扫描速率，这相当于在44 MHz范围内的磁场扫描单位为6.3 kT/s。确定了两个实验领域。在第一种情况下，线性频率扫描速率相对较慢，并且获得纯吸收和纯色散光谱。在目前的技术发展水平上，这似乎是一种切实可行的运作模式。主要优点是消除了正弦磁场调制。在第二种模式下，频率快速扫过频谱的一部分，然后在读出周期内停止频率扫描;来自扫过的线的FID信号以频率单位的线的频谱位置与读出位置之间的差的频率振荡。如果有一条以上的谱线，则振荡叠加。使用YIG振荡器的扫描速率太慢，并且光谱的部分太窄而不能实现傅里叶变换（FT）NMR的完全EPR等效。本文讨论了实现这一目标所需的技术进步。梯形频率扫描是一种使能技术的FT EPR的假设是支持这项研究。
This paper describes a novel experiment on nitroxide radical spin labels using a multiarm EPR W-band bridge with a loop-gap resonator (LGR). We demonstrate EPR spectroscopy of spin labels by linear sweep of the microwave frequency across the spectrum. The high bandwidth of the LGR, about 1 GHz between 3 dB points of the microwave resonance, makes this new experiment possible. A frequency-tunable yttrium iron garnet (YIG) oscillator provides sweep rates as high as 1.8 × 105 GHz/s, which corresponds to 6.3 kT/s in magnetic field-sweep units over a 44 MHz range. Two experimental domains were identified. In the first, linear frequency sweep rates were relatively slow, and pure absorption and pure dispersion spectra were obtained. This appears to be a practical mode of operation at the present level of technological development. The main advantage is the elimination of sinusoidal magnetic field modulation. In the second mode, the frequency is swept rapidly across a portion of the spectrum, and then the frequency sweep is stopped for a readout period; FID signals from a swept line oscillate at a frequency that is the difference between the spectral position of the line in frequency units and the readout position. If there is more than one line, oscillations are superimposed. The sweep rates using the YIG oscillator were too slow, and the portion of the spectrum too narrow to achieve the full EPR equivalent of Fourier transform (FT) NMR. The paper discusses technical advances required to reach this goal. The hypothesis that trapezoidal frequency sweep is an enabling technology for FT EPR is supported by this study.
登录
查看更多内容
影响因子：
1.6
作者：
Sidabras, Jason W.;Mett, Richard R.;Hyde, James S.
通讯作者：
Hyde, James S.
影响因子：
2.2
作者：
Hyde, James S.;Froncisz, Wojciech;Strangeway, Robert A.
通讯作者：
Strangeway, Robert A.
影响因子：
--
作者：
HYDE, JS
通讯作者：
HYDE, JS
影响因子：
--
作者：
WEGER, M
通讯作者：
WEGER, M
影响因子：
--
作者：
Rabi, II
通讯作者：
Rabi, II