Computer controlled [ital in] [ital situ] radiolysis electron spin resonance spectrometer incorporating magnetic field-microwave frequency locking

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1144745· OSTI ID:6712273

Madden, K P; McManus, H J.D.; Fessenden, R W ^[1]

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1. Radiation Laboratory and Department of Chemistry, University of Notre Dame, Notre Dame, Indiana 46556-0769 (United States)

A lab-built personal computer-based electron spin resonance (ESR) spectrometer is described which incorporates a wide range magnetic field/microwave frequency lock as part of its magnetic field control subsystem. Instrument operation is accomplished by keyboard commands, with important experimental variables logged automatically for reference during subsequent data analysis. The spectrometer features both narrowband field modulation and direct-detection time-resolved ESR modes. The data acquisition system and field/frequency lock operate such that spectrum recordings consisting of multiple magnetic field sweeps are undistorted by long-term klystron frequency drift. The spectrometer features low noise microwave preamplification, balanced mixer detection, automatic reference arm phase control, and a fast automatic frequency control system requiring no klystron frequency modulation. Natural abundance [sup 13]C and [sup 33]S studies of the terephthalic acid radical trianion and sulfite radical anion are presented as proof of spectrometer performance.

• OSTI ID: 6712273
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Journal Issue: 1 Vol. 65:1; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
ABUNDANCE
ANIONS
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CONTROL
DATA ACQUISITION SYSTEMS
DECOMPOSITION
DESIGN
DICARBOXYLIC ACIDS
EPR SPECTROMETERS
EVEN-ODD NUCLEI
FREQUENCY CONTROL
IONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC FIELDS
MEASURING INSTRUMENTS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PERFORMANCE TESTING
RADIATION EFFECTS
RADICALS
RADIOLYSIS
SPECTROMETERS
STABLE ISOTOPES
SULFITES
SULFUR 33
SULFUR COMPOUNDS
SULFUR ISOTOPES
TEREPHTHALIC ACID
TESTING