# A High Power, Broadband 395 GHz Gyrotron Amplifier for DNP-NMR and EPR Spectroscopy

> **NIH NIH R44** · BRIDGE 12 TECHNOLOGIES, INC. · 2020 · $365,942

## Abstract

Project Summary / Abstract
We propose to develop a novel gyro traveling wave tube amplifier (gyro-TWT) at 395 GHz with an output
power of 500 W and an operating bandwidth exceeding 3 GHz and a small signal gain > 45 dB. The amplifier
will be used in Dynamic Nuclear Polarization (DNP) enhanced Nuclear Magnetic Resonance (DNP-NMR)
experiments and Electron Paramagnetic Resonance (EPR) experiments. The output power of the proposed
amplifier is three orders greater than those available from solid-state sources at similar frequencies and the
operating bandwidth combined with the ability to coherently amplify complex input signals for use in DNP-NMR
and EPR will enable new generation of pulsed DNP-NMR and EPR experiments that are currently impossible
to perform with free running fixed frequency oscillators. This amplifier can upgrade the currently deployed
dozens of gyrotron oscillators for use in DNP-NMR and provide researchers with the ability of conducting
experiments with a broad range of polarizing agents without the need for a superconducting sweep coils in the
NMR magnet. Also, the amplifier will enable researchers to explore the promise of pulsed DNP-NMR
experiments. The proposed amplifier can be operated with a peak power 500 W with a duty factor of 10 % or in
continuous wave mode with an output power of 50 W.
In Phase I, we will design the amplifier system and perform detailed modeling and simulation of its
performance using benchmarked state-of-the-art design codes used in microwave tube research. We will
present a complete mechanical design of the system and verify the thermal and electrical properties using
commercial finite element codes. We will also build and test the cold performance of the most important
element of the system, namely, the interaction circuit and demonstrate its suitability for integration with the
tube. These tests will be performed on a Vector Network Analyzer to verify the microwave propagation
properties of the device. In Phase II, we will fabricate the electron gun, the internal mode converter and other
auxiliary components such as microwave windows etc. The entire system will be integrated and tested in our
laboratory to demonstrate the proposed output power and bandwidth.

## Key facts

- **NIH application ID:** 10010144
- **Project number:** 1R44GM136125-01A1
- **Recipient organization:** BRIDGE 12 TECHNOLOGIES, INC.
- **Principal Investigator:** Thorsten Maly
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $365,942
- **Award type:** 1
- **Project period:** 2020-06-10 → 2021-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10010144

## Citation

> US National Institutes of Health, RePORTER application 10010144, A High Power, Broadband 395 GHz Gyrotron Amplifier for DNP-NMR and EPR Spectroscopy (1R44GM136125-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10010144. Licensed CC0.

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