Argonne National Laboratory

Nuclear Magnetic Resonance (NMR) Spectroscopy Laboratory

Nuclear Magnetic Resonance (NMR) Spectroscopy Laboratory

The CSE Division in Building 241 has a 500 MHz nuclear magnetic resonance (NMR) spectrometer. Users have recorded spectra of 1H, 2H, 7Li, 11B, 13C, 14N, 15N, 17O, 19F, 25Mg, 27Al, 29Si, 31P, 95Mo, 119Sn, and 195Pt. Full complement of one, two and three-dimensional pulse sequence library is available.

This system uses an UltraShield Plus superconducting magnet with 5.4 cm bore, (operation field at 11.744 Tesla) including vibration isolation magnet stand. It has 300 watts power on the X-channel, 100 watts power on the proton, single axis z-gradient, and variable temperature control. It has 36 room temperature shim and digital lock control, including digital frequency generation, digital quadrature receiver, computer-controlled lock regulation system and ultra-stable, low-current noise Shim Control Boards (SCBs).

RF generation including 2 channels Signal Generation Unit (SGU) for generation of phase, amplitude, and frequency using Direct Digital Synthesis (DDS) covering a frequency range from 6 to 640MHz. Provides <0.01 degree phase increments and <0.005 Hz frequency resolution. Includes 16 MB high performance wave-form memory for programming of experimental sequences including ultra-fast pulse programming, pulse shaping and composite pulse decoupling executable synchronously or asynchronously.

Gradient Controller for simultaneous control of up to three magnetic field gradients with real time generation of gradient shapes.

Digital Receiver Unit with integrated high performance digital filters and Digital Quadrature Detection (DQD) that virtually eliminates quad images and spikes and 60 Hz interference in experiments for large sweep widths.

Second-generation digital quadrature detection receiver with integrated high performance ADCs. Provides very high dynamic range, high digital resolution and large band-width digital filtering.

RF transmitter system, all operations under computer control:

  • X-frequency broadband transmitter system for X-frequency observe and decoupling; for both CW and high power pulse operations; 300 Watt pulse power.
  • 1H, 19F transmitter for observe and homo/heteronuclear decoupling, 100 Watt pulse power with 25 Watt CW.
  • 2H transmitter for decoupling and gradient shimming, 150 Watt pulse power.

Multinuclear broadband observe probe (5 mm sample diameter) with digital tuning covering the range from 15N to 31P and 19F with 1H decoupling. Any nuclei can be automatically selected and optimally tuned and matched. This probe also offers the ability to observe 19F with 1H decoupling and to perform two-dimensional 1H/19F spectroscopy. As two separate coils are used for these two nuclei, artifacts common with double tuning of one coil are eliminated. GRASP II version, including actively shielded Z-gradient coil for use with GRASP II accessory. Automatic Tuning and Matching (ATM) Accessory for computer control of tuning and matching from sample to sample.

Variable Temperature

AH0003 BVT-3200 digital VT control unit, with Eurotherm control module, thermocouple and heater. All functions under full computer control. Temperature accuracy +/- 0.2°C (with +/- 1.0°C room temperature stability). Maximum temperature 200°C.