---
title: 'Cryogenic Systems Engineer at Fuse'
canonical: 'https://feeny.ai/job/cryogenic-systems-engineer-fuse-san-leandro-mrjpakjmj9b6'
type: 'job'
last_seen: '2026-09-08'
---

# Cryogenic Systems Engineer at Fuse

- **Company:** Fuse
- **Location:** San Leandro, CA
- **Compensation:** $110k–$165k
- **Employment:** full-time
- **Posted:** 2026-08-19
- **Last confirmed live:** 2026-09-08
- **Apply:** https://jobs.ashbyhq.com/fuse/bac78943-8667-4650-a193-0005cd7841f5

## Job description

## ABOUT FUSE

We are building one of the most potentially consequential companies of the century. Our mission is to accelerate the world's transition to fusion energy while safeguarding humankind. This is not a normal company. This is not a normal job. We are committed for the long term to win.

## ABOUT THE ROLE

Fuse is constructing Z-Star, a next-generation pulsed-power facility. Z-Star requires two deeply integrated cryogenic systems: a high-vacuum cryopumping system and a 4 K target/liner cryogenic cooling system.

As the Cryogenic Systems Engineer, you'll design, commission, operate, and maintain both systems and serve as the facility's resident expert in cryogenic and vacuum science.

## CORE RESPONSIBILITIES

Cryopump System Design & Operations

- Design, procure, install, and commission the multi-stage vacuum system for the Z-Star chamber, including turbomolecular roughing pumps, cryopump arrays, and associated gate valves, interlocks, and controls.
- Define cryopump sizing, placement, and regeneration schedules to meet target base pressure and shot-repetition-rate requirements.
- Develop and maintain vacuum protocols including chamber venting, backfilling with inert gas, and controlled pump-down procedures compatible with shot operations.
- Monitor and trend vacuum performance; diagnose and resolve outgassing sources, virtual leaks, and pump degradation.

4 K Target Cryogenic System

- Design and commission the liquid helium cryostat and cryogenic delivery system for liner/target cooling, including vacuum-jacketed transfer lines, LHe reservoir management, and temperature-control instrumentation.
- Develop procedures for target loading, cool-down, hold time at 4 K, and rapid warm-up following a shot.
- Characterize and minimize cryogenic heat loads from radiation, conduction, and parasitic pathways to maintain stable 4 K conditions through the target preparation window.

Cryogenic Infrastructure Management

- Manage liquid helium and liquid nitrogen supply, storage dewars, and transfer operations on-site, including logistics, safety, and vendor relationships.
- Maintain all cryogenic hardware: cryopumps, compressors, cold heads (Gifford-McMahon or Pulse Tube), transfer lines, pressure-relief systems, and monitoring instrumentation.
- Develop and implement a preventive-maintenance program for all cryogenic and vacuum equipment aligned with the facility shot schedule.
- Train facility operations staff on cryogenic safety procedures and emergency response.

Diagnostics & Instrumentation

- Specify, install, and maintain cryogenic instrumentation: Cernox or PT-100 temperature sensors at multiple stages, capacitance manometers, ionization gauges, residual gas analyzers (RGA), and pressure transducers.
- Integrate cryogenic-system monitoring into the facility control and interlock system.

Safety & Compliance

- Author and enforce cryogenic safety procedures, including ODH assessments, pressure-vessel requirements, LHe handling, and cold-burn precautions, in compliance with applicable U.S. codes.
- Perform pressure-vessel and cryostat inspection and documentation per applicable ASME/CSA standards.

## MINIMUM QUALIFICATIONS

- B.Sc. or M.Sc. in Physics, Mechanical Engineering, Engineering Physics, or Chemical Engineering with demonstrated cryogenics specialization.
- 2+ years of hands-on experience designing, operating, or maintaining cryogenic systems at liquid-helium temperatures (4 K) in a research or industrial facility.
- Proficiency with cryopump systems including sizing, installation, and regeneration cycles.
- Strong working knowledge of vacuum science and technology: pumping speed, conductance, outgassing, leak detection using He mass spectrometry, residual gas analysis, and pressure measurement.
- Experience designing or operating liquid-helium dewars, cryostats, and VJ transfer lines.
- Familiarity with cryogenic instrumentation including thermometry, pressure, flow, and liquid-level measurement from 4 K to 300 K.

## PREFERRED QUALIFICATIONS

- Experience with fusion energy, pulsed power, or particle-accelerator cryogenic systems, particularly high-voltage-isolated cryogenic assemblies.
- Familiarity with MagLIF-type target cryostats or ICF cryogenic target-preparation systems.
- Experience with Gifford-McMahon (GM) or Pulse Tube (PT) cryocoolers for closed-cycle refrigeration.
- Knowledge of cryogenic safety standards including ASME Section VIII, CGA G-5.4, ODH analysis procedures, and pressure-relief system design.
- Experience with large vacuum-chamber systems (>10 m³) in a pulsed or repetitive-shot experimental facility.
- Proficiency in thermal modeling and simulation using ANSYS, COMSOL, or equivalent tools.

## WHAT WE VALUE

- Give a shit. Build things you're proud of.
- Take responsibility. If something is broken and you can fix it, fix it. See things through.
- Move fast. Make decisions, learn quickly, and keep moving forward.
- Think bigger. Simplify relentlessly. Don't default to the safe answer.
- Disagree and commit. The best idea wins. Once a decision is made, we move.
- Desire to win. This is hard. Expect intensity. We are here to win.
- Plan B is to make Plan A work.

## BENEFITS

- Medical, dental, and vision coverage.
- Relocation assistance for roles that require it.
- Flexible time off. Take what you need, no accrual tracking.
- 2 weeks of paid time off built into the end of each year, subject to team and business needs.
- Supportive leave of absence policies.
- Paid leave for new parents.

## ITAR REQUIREMENTS

To conform to U.S. Government technology export regulations, including the International Traffic in Arms Regulations (ITAR), you must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State.

## EQUAL OPPORTUNITY

Fuse is an Equal Opportunity Employer; employment with Fuse is governed on the basis of merit, competence, and qualifications and will not be influenced by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, ancestry, immigration status, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.

## About Fuse

## Company Overview
- **One-liner**: Fuse is a fusion energy and defense company developing magnetized-liner inertial fusion (MagLIF) technology to deliver clean, on-demand power while providing radiation testing services for national security customers.
- **Entity Type**: Private (Series A)
- **Headquarters**: San Leandro, California, United States (operates "Fuseville" facility)
- **Founded**: 2018 (per CB Insights) or 2019 (per Wikipedia); founder J.C. Btaiche started the company at age 19
- **Founders**: J.C. Btaiche

## Core Business
- **Primary industry/industries**: Fusion energy, defense, nuclear effects testing, pulsed power engineering
- **Target customers**: U.S. government (Air Force, NNSA, national labs), defense contractors, eventually commercial energy utilities
- **Mission or purpose statement**: "Accelerating the World’s Transition to Fusion Energy" — building the fastest practical path to abundant, clean, safe, on-demand energy

## Products & Services
- **TITAN**: A 1 TW Impedance-Matched Marx Generator (IMG) — the essential MagLIF pulser building block. World’s first high-energy, high-power IMG, demonstrated in 2024 with results published in *Nature Scientific Reports*.
- **Z-Star**: A 15 TW MagLIF generator designed to iterate on and solve system engineering challenges (targeting 2027).
- **Apeiron I**: A pilot fusion plant design aiming to demonstrate a MagLIF hybrid plant core (targeting 203x).
- **FAETON I**: Neutron-producing fusion generator (over 1 trillion neutrons generated).
- **Radiation Testing Services (HEART)**: Hardened Electronics And Radiation Testing — providing short-burst radiation testing for government and commercial hardware resilience.

## Market Standing
- **Valuation**: Over $200 million as of September 2024 (per Bloomberg News)
- **Total Funding**: $32 million raised (Series A)
- **Key Metric**: 100+ employees; 2 patents filed; 53 employees as of 2024 (Wikipedia)
- **Notable Investors/Partners**: Bracket Capital, Tamarack Global, Buckley Ventures. Government partners: U.S. Air Force, National Nuclear Security Administration, Sandia National Laboratories, Los Alamos National Laboratory.
- **Growth Signals**: Awarded USAF contract (Feb 2024); published in *Nature Scientific Reports* (July 2024); former NNSA Administrator Lisa Gordon-Hagerty joined board; building Z-Star and Apeiron I platforms; operating a radiation facility covered by *Wired*.

## Competitive Advantages
- **MagLIF approach**: Integrates proven fusion technologies (magnetic and inertial) — demonstrated feasible by Sandia National Lab (2018, 2022). Fuse’s focus on engineering efficiency and affordability aims to solve repetition rate and cost barriers.
- **Rapid iteration**: Delivered two neutron-producing fusion generators and the world’s first IMG pulser in under three years, on time and on a lean budget.
- **Dual-use revenue model**: Generates revenue now through nuclear effects testing for defense customers while developing long-term fusion power — de-risking the path to commercial fusion.
- **Deep government relationships**: Contracts with USAF, NNSA, and CRADAs with Sandia and Los Alamos. Advisory board includes former Under Secretary of Energy, former CIA COO, former NSA Deputy Director, and senior military officers.
- **Patents**: 2 filed patents protecting core technology.

## Strategic Focus
- **Immediate**: Scale the pulsed power driver technology (Z-Star) and continue delivering radiation testing services to defense and intelligence customers.
- **Medium-term**: Demonstrate a MagLIF hybrid plant core with Apeiron I.
- **Long-term**: Deploy commercial fusion power plants, achieving 90% energy efficiency and enabling clean, on-demand energy at scale.
- **Talent**: Aggressively hiring for plasma physics, electrical engineering, pulse power, mechanical engineering, and experimental physics roles.

## Why Work Here
- **Culture**: Described as "misfits, tinkerers, skeptics, doers" — drawn to impossible problems. Values include frugality, speed, hands-on experimentation, and deep technical conviction. "Fuse is not a comfortable environment" — no bean bag chairs; many live, eat, and work at the facility.
- **Work environment**: "Fuseville" — a shipping-container communal living facility adjacent to the lab. Bed-to-reactor commute under 60 seconds. Sleep pods available. You'll likely build your own desk. "We really skimp on furniture."
- **Compensation**: Low salaries — "you should be willing to work for free. While you will receive a minimum base so that you can survive, money and lifestyle is not the motivator." Significant stock option upside if fusion succeeds. "Fair wages. Long hours. High voltage. Success far from guaranteed."
- **Benefits**: Competitive healthcare plan. High-end computer setup and cloud computing resources. "Everyone on the team has skin in the game."
- **Who should apply**: Self-motivated, deeply internally driven, humble yet brilliant, fusion geeks who built Polywells in high school, boundary-pushers who "get shit done." Must be comfortable with deferred gratification and high risk.
- **Remote/hybrid policy**: Not explicitly stated, but the "Fuseville" on-site living model suggests heavy in-person presence is expected. "Commuting makes your blood boil" is a stated value.
- **Notable perks**: Working on one of humanity’s hardest problems alongside top 1% talent; national security impact; potential enormous financial reward via stock options; "glory in case of ignition."

## Sources
1. [f.energy](https://www.f.energy/)
2. [f.energy - About](https://www.f.energy/about-fuse-energy)
3. [f.energy - Join Us](https://www.f.energy/join-us)
4. [CB Insights](https://www.cbinsights.com/company/fuse-energy-technologies)
5. [Wikipedia](https://en.wikipedia.org/wiki/Fuse_Energy_Technologies_Corporation)
6. [Jobs page](https://jobs.ashbyhq.com/fuse)

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