JES-X320 Electron Spin Resonance Spectrometer

The JES-X320 provides high sensitivity with an easy operation environment.


  • Spectrometer designed to be user friendly
    --High-sensitivity ESR equipped with ultra-low noise microwave source
    --Easy-to-use operation interface under Windows10™
    --Auto-tuned microwave circuit and built-in frequency counter
    --Flexible sequential measurements including randomized values of parameters, e.g. sample temperature, angular rotation, etc.
  • Low noise high stability microwave unit
    The JEOL solid-state Gunn diode element provides long life (20,000 hours or more), stable operation, and high reproducibility
  • High sensitivity cavity
    Cylindrical type resonator TE011 can accommodate larger samples and provides for better modulation uniformity
  • High-homogeneity, high resolution, high stability Electromagnets
    The JES-X320 employs a magnetic field linear sweep circuit based on the magnetic field detection system using a Hall element
JES-X320 Electron Spin Resonance Spectrometer

JES-X3 Available Models

  Pole Diameter Pole Gap Max. Field (T) Homogeneity Sensitivity
JES-X310 15 cm 60mm 0.65 5 x 10-6 5 x 109 spins / 10-4 T
(at 100 kHz modulation)
JES-X320 24 cm 62mm 1.30 5 x 10-6 5 x 109 spins / 10-4 T
(at 100 kHz modulation)
JES-X330 36 cm 75mm 1.40 5 x 10-6 5 x 109 spins / 10-4 T
(at 100 kHz modulation)
Select from 3 Magnets According to Research Requirements

Contact Us

  • Contact your local Sales Representative to schedule a virtual demo now
    (USA, Canada, Mexico, Brazil)

Learn More

Download the JES-X3 Series product brochure

You can also read an in-depth published article on the history of JEOL NMR and ESR

Key Features

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 below, obtained for Tempol/ Benzene solution (1 uM), by using a 100 kHz modulation frequency, clearly shows a guaranteed sensitivity of 5.0x109 spins/0.1 mT.

ESR High Sensitivity

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.
ESR High Resolution
The JES-X320 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-X320 employs a Hall element with good linearity, and the entire Hall element is thermally controlled to guarantee a magnetic field stability as high as 5 x 10-6 / 0C・h. The high stability shown is 100 times superimposed ESR spectra of perylene cation radical with ±0.1 mT magnetic field sweep in one hour measurement.

ESR High Stability

Request JES-X320 Product Info / Virtual Demo

  • Product / Page of Inquiry: JES-X320

  • By completing and submitting this form, you agree to the JEOL USA, Inc. Privacy Policy, and that your information may be shared with JEOL USA, Inc. and other JEOL affiliates.

JEOL Ltd. global website
    JEOL USA, Inc.
    11 Dearborn Road
    Peabody, MA 01960
    © Copyright 2023 by JEOL USA, Inc.
    Terms of Use
    Privacy Policy
    Cookie Preferences