|
 PO Box 924, Jackson, MI 49204 1 (800) 622-2866 |
HOME |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The postulate of Pauli in 1924 that certain nuclei posses a spin angular momentum led Gerlach and Stern to experimental confirmation that nuclei had magnetic moments. In 1939 Rabi first demonstrated resonance absorption of an oscillating electromagnetic field by molecules placed in a constant magnetic field. The first unsuccessful NMR experiment in solid state was performed in 1936 by Gorter. It was successfully done in 1946 independently by 2 groups, Purcell at Harvard and Bloch at Stanford (Nobel Prize in 1952). Later in 1950 Hahn implemented an ingenious idea of replacing continuous wave excitation of polarized nuclei by pulse excitation. In 1951 Arnold went beyond the limits of magnet homogeneity and obtained the first high-resolution spectra discovering 1H chemical shifts. Hahn’s pulse spectroscopy idea matured in the 1960’s when technology allowed Anderson and Ernst the use of computers for Fourier Transformations (for his contribution to modern NMR Ernst received the Nobel Prize in 1991). This allowed one to change time domain to frequency domain in one keystroke. The age of medical applications started in the early 1970’s after Lautertbur demonstrated the feasibility of using NMR for imaging. Liberated from the obsession of perfect magnetic field homogeneity he deliberately applied gradients to encode the spatial information into an NMR spectrum. This and Damadian’s discovery in 1971 about tissue contrast available through variation of nuclear relaxation times opened Pandora’s box for medical application. Since its discovery, NMR has proved to be a versatile technique in basic research (Physics, Chemistry, Biochemistry). It found application in Geology (oil and ferrous compounds search), Agriculture and Food Industries (moisture contents and purity measurements), and in Archeology (tracing changes of the Earth’s magnetic field through the ages). Finally materializing under the MRI acronym Magnetic Resonance Imaging; (for “political” reasons the word “nuclear” was removed) Lauterbur’s idea on “Image Formation by Induced Local Interactions” proved to be a perfect modality for clinical noninvasive anatomical and functional imaging. Not surprisingly the 2003 Nobel prize in Medicine was awarded to Chemist Lauterbur and Mansfield, a Physicist who invented modern MR Imaging. SPECTROMETER DESCRIPTION Tel-Atomic, Inc. presents a desktop pulse NMR system, the PS-15, that combines all of the sophisticated features that mainframe spectrometers have including:
The spectrometer can operate with or without NMR magnetic field stabilization. The NMR stabilizer provides excellent long-term stability of the electromagnet by compensating for thermal drift. This stability is necessary for experiments that require long times (for example multiple signal accumulation, samples with very long relaxation times). With the NMR flux stabilizer turned off diagnostics like confirming the magnet’s homogeneity (shimming) and adjustment of initial current (I 0 ) of the basic magnet current stabilizer can be performed. ATTENUATORS The PS-15 includes 2 attenuators for changing the pulse power. The main attenuator has a range of 0-31.5 dB in 0.5 dB steps. This attenuator changes the power of pulses simultaneously in all channels. This means very accurate adjustment of the exciting pulse. Samples with short relaxation times (solids) need short high-power pulses. For samples with long relaxation times (liquids) long, low-power is more adequate. The Y channel attenuator changes the power of pulses in Y channel only. It is active only during rotating frame experiments. It is used for calibration and selecting of the locking B1 field for T 1ρ measurements.
The spectrometer operation is controlled by a package of dedicated software for user-friendly assistance during the preparation of an experiment, the actual acquisition of data and later data processing. The software provides a convenient means for the acquisition of any form of nuclear signal related to NMR spectroscopy or relaxometry and its subsequent processing. The software graphic interface consists of three windows: setup, acquisition, and processing.
Documentation An experimental manual, on CD, gives the student full flexibility with respect to the level of involvement and the applications of magnetic resonance spectroscopy one wishes to explore. Twenty plus basic and advanced, as well as instrumentation experiments are included in the experimental manual. Basic experiments include, NMR Specta, and Relaxation experiments. Advanced experiments such as multiple pulse sequences and rotating frames of reference, as well as, angle dependence on spectra shape lets the student explore more deeply into the uses of NMR. Instrumentation experiments are designed to teach the student about NMR instrumentation. A number of samples for use with the experiments in the experimental manual have been included for convenience and ease of use. The student however is not limited to these samples. The number of potential samples (chemical compounds, commercial substances or products) and measurements are practically unlimited. TEL PS-15 Pulsed NMR System The complete system includes the PS-15 control unit, electromagnet with integrated probe head, accessories, a CD which includes the software, a 100 page operations manual and the 140 page experimental manual (in PDF format), as well as all connecting cables. The unit is shipped in an exceptionally well built case that can be used for storing the unit.
Hard copy of the PS-15 Manual A printed version of the experimental and operations manual is available. Both the 100 page operating manual and the 140 page experimental manual are contained in a single sturdy 3 ring binder.
Computer requirements and software installation: Computer considerations For proper operation, data storage and display, the spectrometer winner control program requires an IBM PC AT VGA or compatible computer. The program and factory created files occupy less than 2MB of hard drive total space. Average spectroscopy binary data files need only about 10 Kb of space, but expand as much as 5 times when converted into text files. Average relaxation binary data files occupy about 100 Kb, but collapse to 1 Kb when amplitudes and corresponding delays are extracted for further relaxation time calculations. Processed spectra occupy about 25 Kb. Exact numbers depend on number of data points acquired. Even if intensively used, the software generally needs only moderate space on the hard disk.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Need technical information or to place an order? TEL-Atomic 1-800-622-2866 | |||
|
Teltron Products Tel-X-Ometer X-Ray & Accessories Electron Tubes Spectroscope Thermodynamics Radiometer Leslie's Cube Stefan-Boltzmann |
Nuclear Systems Multichannel Analyzer Counters Basic Systems Spin Resonance Systems |
Other Products | |
|
Kater Pendulum Photogate Air Tracks Oscilloscopes Instrumentation Sweep Generator with Counter Multimeters |
Superconductivity Photoelectric Effect Cloud Chamber Planck's Constant Rutherford Scattering Apparatus Speed of Light Apparatus Magnetic Bubble Apparatus Millikan Apparatus Smart Magnetic Sensor Power Supplies |
||
|
Warranty, Freight & Terms Contact TEL-Atomic |
|||
|
sales@telatomic.com
|
|||