公开(公告)号：US20100026302A1

公开(公告)日：2010-02-04

申请号：US12518946

申请日：2007-11-18

申请人： F. David Doty ,  Siddarth Shevgoor

发明人： F. David Doty ,  Siddarth Shevgoor

IPC分类号： G01R33/44 ,  G01R33/48

CPC分类号： G01R33/307 ,  G01R33/31 ,  G01R33/34015 ,  G01R33/34092

摘要： All critical circuit components, including the sample coils, are located along with the spinner assembly in a region that may be evacuated to high vacuum for thermal insulation and high-voltage operation. A hermetically sealed spinner assembly simultaneously satisfies the requirements of hermeticity, low total emissivity, rf compatibility, spinning performance, magnetic compatibility, and high filling factor by utilizing metal construction except for the central region near the rf sample coils. Hence, it is possible to maintain high vacuum in the region external to the MAS spinner assembly even over a broad range of bearing and drive gas temperatures. A bundle of optical fibers is provided for tachometry for spin rates up to 60 kHz. The use of alumina disc capacitors allows the noise contributions from the most critical capacitors to be reduced to a minor fraction of the total and simplifies high voltage operation.

摘要翻译： 包括样品线圈在内的所有关键电路部件与旋转器组件一起位于可以被抽空到高真空以进行绝热和高压操作的区域中。 密封的旋转器组件通过利用除了rf样品线圈附近的中心区域之外的金属结构，同时满足气密性，低总发射率，低相容性，旋转性能，磁兼容性和高填充系数的要求。 因此，即使在宽范围的轴承和驱动气体温度下，也可以在MAS旋转器组件外部的区域中保持高真空。 提供一束光纤用于高达60 kHz的旋转速度的转速。 使用氧化铝盘式电容器可以将最关键的电容器的噪声贡献降低到总体的一小部分，并简化高压运行。

公开(公告)号：US07282919B2

公开(公告)日：2007-10-16

申请号：US11275933

申请日：2006-02-06

申请人： F David Doty ,  Siddarth Shevgoor

发明人： F David Doty ,  Siddarth Shevgoor

IPC分类号： G01V3/00

CPC分类号： G01R33/307 ,  G01R33/31

摘要： “An MAS probe is disclosed for obtaining a substantial improvement in signal to noise (S/N) in triple-resonance high-resolution (HR) magic-angle-spinning (MAS) NMR of samples near room temperature (RT) in high-field magnets where the magnet's RT shim bore is greater than 60 mm. All critical circuit components, including the sample coils, are located along with the spinner assembly in a thermally insulated cold zone pressurized with helium gas. The spinner assembly attaches to a sealed, curved, rotor-loading tube to permit automatic sample change, and it is surrounded by a partially insulated jacket cooled with a cryogenic fluid, generally nitrogen gas. The MAS probe is also compatible with magic angle gradients, variable temperature operation, field locking, and commonly available closed-cycle cold fingers.”

摘要翻译： “公开了一种MAS探针，用于获得在室温（RT）附近的样品的三重谐振高分辨率（HR）魔角旋转（MAS）NMR中的信噪比（S / N） 所有关键电路部件（包括样品线圈）都与旋转器组件一起放置在用氦气加压的绝热冷区中，旋转器组件连接到密封的， 弯曲的转子加载管，允许自动样品更换，并由被低温液体（通常为氮气）冷却的部分绝缘套管包围，MAS探头也兼容魔角梯度，可变温度操作，场锁定和 常用的闭环冷手指“。

公开(公告)号：US07915893B2

公开(公告)日：2011-03-29

申请号：US12518946

申请日：2007-11-18

申请人： Siddarth Shevgoor ,  F David Doty

发明人： Siddarth Shevgoor ,  F David Doty

IPC分类号： G01V3/00

CPC分类号： G01R33/307 ,  G01R33/31 ,  G01R33/34015 ,  G01R33/34092

摘要： All critical circuit components, including the sample coils, are located along with the spinner assembly in a region that may be evacuated to high vacuum for thermal insulation and high-voltage operation. A hermetically sealed spinner assembly simultaneously satisfies the requirements of hermeticity, low total emissivity, rf compatibility, spinning performance, magnetic compatibility, and high filling factor by utilizing metal construction except for the central region near the rf sample coils. Hence, it is possible to maintain high vacuum in the region external to the MAS spinner assembly even over a broad range of bearing and drive gas temperatures. A bundle of optical fibers is provided for tachometry for spin rates up to 60 kHz. The use of alumina disc capacitors allows the noise contributions from the most critical capacitors to be reduced to a minor fraction of the total and simplifies high voltage operation.

摘要翻译： 包括样品线圈在内的所有关键电路部件与旋转器组件一起位于可以被抽空到高真空以进行绝热和高压操作的区域中。 密封的旋转器组件通过利用除了rf样品线圈附近的中心区域之外的金属结构，同时满足气密性，低总发射率，低相容性，旋转性能，磁兼容性和高填充系数的要求。 因此，即使在宽范围的轴承和驱动气体温度下，也可以在MAS旋转器组件外部的区域中保持高真空。 提供一束光纤用于高达60 kHz的旋转速度的转速。 使用氧化铝盘式电容器可以将最关键的电容器的噪声贡献降低到总体的一小部分，并简化高压运行。

公开(公告)号：US07170292B2

公开(公告)日：2007-01-30

申请号：US11163344

申请日：2005-10-14

申请人： F. David Doty ,  Siddarth Shevgoor

发明人： F. David Doty ,  Siddarth Shevgoor

IPC分类号： G01V3/00

CPC分类号： G01R33/307

摘要： An improved axial gas bearing for a gas-driven NMR MAS sample rotor is disclosed that utilizes inward flow with a low rotational component over a rotor conical end. A conical flow region is formed between the rotor conical end and a conical stator bearing surface such that the included angle defining the stator surface is not less than the included angle defining the rotor conical end. Gas is injected radially inward with a significant axial rearward component from a number of small holes at high velocity from the periphery into the conical flow region. Compared to the radial velocity components, the tangential flow components of the injected gas are small and preferably opposed to the direction of the rotor rotation. The high and accelerating negative radial velocities may result in significant Bernoulli effect, such that the mean axial pressure over the conical rotor end may be less than atmospheric pressure for a given axial clearance, but as the clearance decreases, the hydrostatic effects exceed the Bernoulli effects and the mean axial pressure over the conical rotor end may then exceed atmospheric pressure by a substantial amount. Thus, a self-stabilizing axial bearing is formed with improved stability and stiffness for rotor surface speeds up to at least 80% of the speed of sound. Motive power required to spin the rotor may be provided by a radial-inflow microturbine at the opposite end of the rotor in a way that is readily compatible with automatic sample change.

摘要翻译： 公开了用于气体驱动的NMR MAS样品转子的改进的轴向气体轴承，其在转子锥形端部上利用具有低旋转分量的向内流动。 在转子锥形端和锥形定子支承表面之间形成锥形流动区域，使得限定定子表面的夹角不小于限定转子锥形端的夹角。 从外围向圆锥形流动区域以高速度从许多小孔径向向内注入气体，其中显着的轴向向后分量从许多小孔注入。 与径向速度分量相比，注入气体的切向流分量较小，优选与转子旋转方向相反。 高和加速的负径向速度可能导致明显的伯努利效应，使得对于给定的轴向间隙，锥形转子端上的平均轴向压力可能小于大气压力，但是随着间隙减小，静水压力效应超过伯努利效应 并且锥形转子端部上的平均轴向压力然后可以超过大气压力大量。 因此，自稳定轴向轴承形成具有改善的稳定性和刚度，用于高达声速的至少80％的转子表面速度。 旋转转子所需的动力可以由转子相对端的径向流入微型涡轮机以与自动样品更换容易相容的方式提供。

公开(公告)号：US20060176056A1

公开(公告)日：2006-08-10

申请号：US11275933

申请日：2006-02-06

申请人： F. Doty ,  Siddarth Shevgoor

发明人： F. Doty ,  Siddarth Shevgoor

IPC分类号： G01V3/00

CPC分类号： G01R33/307 ,  G01R33/31

摘要： An MAS probe is disclosed for obtaining a substantial improvement in signal to noise (S/N) in triple-resonance high-resolution (HR) magic-angle-spinning (MAS) NMR of samples near room temperature (RT) in high-field magnets where the magnet's RT shim bore is greater than 60 mm. All critical circuit components, including the sample coils, are located along with the spinner assembly in a thermally insulated cold zone pressurized with helium gas. The spinner assembly attaches to a sealed, curved, rotor-loading tube to permit automatic sample change, and it is surrounded by a partially insulated jacket cooled with a cryogenic fluid, generally nitrogen gas. The MAS probe is also compatible with magic angle gradients, variable temperature operation, field locking, and commonly available closed-cycle cold fingers. One major challenge in implementing CryoMAS is solving the problem of gas leakage from the spinner bearing, drive, and exhaust nitrogen into the cold zone, as some components will necessarily be ceramic, some plastic, and some metal. It is not desirable to use helium for the spinner bearing and drive gases for cost reasons and to prevent risk of degradation of o-ring-sealed magnet cryostats. A pressurized helium atmosphere in the cold zone may be utilized to prevent nitrogen flow from the spinner exhaust streams or atmosphere into the cold zone. The drawback to a pressurized cold zone is that the heat transfer coefficient in dense helium at low temperatures is very high, making it challenging to cool the sample coils and all the large, critical, circuit components in a practical manner. Part of the solution here is to use a first-stage cooling-jacket around the major heat leaks near the spinner exhaust flows. The critical components may be insulated with fine glass wool or teflon foam and conduction cooled without cooling much of the cold zone below the temperature of the first-stage cooling. The use of coaxial sapphire capacitors allows the noise contributions from the most critical capacitors to be reduced to a minor fraction of the total.

公开(公告)号：US20060082371A1

公开(公告)日：2006-04-20

申请号：US11163344

申请日：2005-10-14

申请人： F. Doty ,  Siddarth Shevgoor

发明人： F. Doty ,  Siddarth Shevgoor

IPC分类号： G01V3/00 ,  H02K1/22

CPC分类号： G01R33/307

摘要： An improved axial gas bearing for a gas-driven NMR MAS sample rotor is disclosed that utilizes inward flow with a low rotational component over a rotor conical end. A conical flow region is formed between the rotor conical end and a conical stator bearing surface such that the included angle defining the stator surface is not less than the included angle defining the rotor conical end. Gas is injected radially inward with a significant axial rearward component from a number of small holes at high velocity from the periphery into the conical flow region. Compared to the radial velocity components, the tangential flow components of the injected gas are small and preferably opposed to the direction of the rotor rotation. The high and accelerating negative radial velocities may result in significant Bernoulli effect, such that the mean axial pressure over the conical rotor end may be less than atmospheric pressure for a given axial clearance, but as the clearance decreases, the hydrostatic effects exceed the Bernoulli effects and the mean axial pressure over the conical rotor end may then exceed atmospheric pressure by a substantial amount. Thus, a self-stabilizing axial bearing is formed with improved stability and stiffness for rotor surface speeds up to at least 80% of the speed of sound. Motive power required to spin the rotor may be provided by a radial-inflow microturbine at the opposite end of the rotor in a way that is readily compatible with automatic sample change.

摘要翻译： 公开了用于气体驱动的NMR MAS样品转子的改进的轴向气体轴承，其在转子锥形端部上利用具有低旋转分量的向内流动。 在转子锥形端和锥形定子支承表面之间形成锥形流动区域，使得限定定子表面的夹角不小于限定转子锥形端的夹角。 从外围向圆锥形流动区域以高速度从许多小孔径向向内注入气体，其中显着的轴向向后分量从许多小孔注入。 与径向速度分量相比，注入气体的切向流分量较小，优选与转子旋转方向相反。 高和加速的负径向速度可能导致明显的伯努利效应，使得对于给定的轴向间隙，锥形转子端上的平均轴向压力可能小于大气压力，但是随着间隙减小，静水压力效应超过伯努利效应 并且锥形转子端部上的平均轴向压力然后可以超过大气压力大量。 因此，自稳定轴向轴承形成具有改善的稳定性和刚度，用于高达声速的至少80％的转子表面速度。 旋转转子所需的动力可以由转子相对端的径向流入微型涡轮机以与自动样品更换容易相容的方式提供。