DEVELOPMENT OF PULSED ELECTRON NUCLEAR DOUBLE RESONANCE (ENDOR) AT 140 GHZ

140 GHZ 脉冲电子核双共振 (ENDOR) 的发展

• 批准号: 6118649
• 负责人: MARINA L BENNATI
• 金额: $ 1.93万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-15 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6118649
• 关键词: AIDS; bioimaging /biomedical imaging; biomedical resource; human tissue; immunology; infection; inflammation; lymphatic system; magnetic resonance imaging; mental disorders; nervous system; virus

We developed a spectrometer for pulsed ENDOR at 140 GHz, which is based on three new main units a magnet utilizing a 1 0.4 T superconducting sweep coil and a 2 H-NMR field lock system, a 139.5 GHz microwave bridge with four phase capabilities operating in reflection mode, and a probe for EPR/NMR double resonance. The probe consists of a TEOI I cavity adapted for RF irradiation and a high-quality resonance circuit with autotuning capability for variable radio frequency irradiation. For pulsed EPR we obtain 90* pulses of 60 - 70 ns and an absolute sensitivity of 3.109 spins/Gauss at 20 K. The performance of the spectrometer was demonstrated with pulsed ENDOR spectra of a standard bis-diphenylene-phenyl-allyl (BDPA) doped into polystyrene and of the tyrosyl radical from E. coli Ribonucleotide Reductase (RNR). The EPR spectrum of the RNR tyrosyl radical displays substantial g-anisotropy at 5 T and was used to demonstrate orientation selective Davies-ENDOR.

我们开发了一个140千兆赫脉冲ENDOR光谱仪，也就是