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JES-X330 Electron Spin Resonance Spectrometer

JES-X330The JES-X330 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

  • High sensitivity cavity

Cylindrical type resonator can accommodate larger samples and provides for better modulation uniformity

  • High-homogeneity, high resolution, high stability Electromagnets

The JES-X330 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-X330 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-X330 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.