The JES-FA200 provides the world's highest sensitivity with a highly refined operational environment.
Features
- Spectrometer designed for user friendly on-line operation
Powerful self-diagnosis function
Built-in frequency counter
Registration of measurement conditions in parameter file
Remote-controlled microwave circuit
Spectrum display on touch screen
- Low noise high stability microwave unit
The JEOL solid-state oscillation element provides long life (20,000 hours or more), stable oscillation, and high output reproducibility
Cylindrical type resonator can accommodate larger samples and provides for better modulation uniformity
- High-homogeneity, high resolution, high stability Electromagnets
The JES-FA200 employs a magnetic field linear sweep circuit based on the magnetic field detection system using a Hall element
| High Sensitivity |
Higher sensitivity measurement is feasible by using a Gunn oscillator which supplies a noiseless stable microwave, a TE011 cylindrical cavity with a high Q-value, a large sample volume, and a modulation coil capable of obtaining a homogeneous magnetic field. The ESR spectrum at left, obtained by using a 100 kHz modulation frequency, clearly shows a guaranteed sensitivity of 7.0x109 spins/0.1 mT. |
Shown is an ESR spectrum of weak pitch, which has so far been used for sensitivity evaluation. The sensitivity obtained is S/N >900, literally the world's highest level. |
| High Resolution |
The magnet polepiece is made of a high-purity material which is precision machined and provides for a homogeneous magnetic field. Ring shims are attached to polepiece surfaces to allow use of a wide high-homogeneity range. In order to obtain high resolution, a cavity made of materials without impurities such as ferromagnetic material, a highly stable power supply for the magnet, and stable magnetic field modulation are required, besides the magnet with a homogeneous magnetic field.
The JES-FA200 is well designed to meet these requirements. Shown above is an ESR spectrum of Coppinger radical. The smallest split coupling of t-butyl base 4.7 uT, and its split shows a 2.35 uT resolution. |
| High Stability |
In order to obtain data with excellent reproducibility, a stable and linear magnetic field is necessary. To obtain a stabilized static magnetic field, the JES-FA200 employs a Hall element with good linearity, and the entire Hall element is thermally controlled to guarantee a magnetic field stability as high as 1 x 10-5 / 0C . h. The high stability shown is 20 times superimposed ESR spectra of perylene cation radical with ±0.1 mT magnetic field sweep in one hour measurement. |