Zachary Seth Hartwig

Zachary Seth Hartwig

he/him
Nuclear Science and Engineering
Signposts on the way to new territory

“Zach is a human being before a scientist. And boy he is an amazing engineer!”, one of his nominators exclaimed.

Zachary Seth Hartwig is an Associate Professor in the Department of Nuclear Science and Engineering (NSE) with a co-appointment at the MIT Plasma Science and Fusion Center (PSFC). He has worked in the areas of large-scale applied superconductivity, magnet fusion device design, radiation detector development, and accelerator science and engineering. His active research focuses on the development of high-field superconducting magnet technologies for fusion energy and accelerated irradiation methods for fusion materials using ion beams.

“Got your back”

One nominator expressed “although he didn’t formally become my advisor until after I submitted my thesis prospectus, I always felt like Zach had my back.” This feeling of support appears to be a common experience among his advisees, with a number of students sharing positive experiences when working alongside Hartwig. 

For example, when the pandemic started, Hartwig made sure that the student had ongoing support and a safe place to simply exist as an international visiting student during a tumultuous time. This care often presented in small ways: when the mentee needed to debug their cryogenic system, Hartwig showed up at the lab every day to plan the next test with them; this same student struggled to write the introduction of their first paper, Hartwig continued to provide support; and when the student wanted to practice for their qualifying exam, Hartwig insisted on helping until the last day. Additionally, when the advisee’s funding was nearing its end, Hartwig secured transition support to bridge the gap.

The nominator reflected on Hartwig’s cheerful and positive mentorship style, noting that “through it all, he… always valued my ideas, he was never judgmental, he never raised his voice, he never dismissed me.” 

Hartwig characterizes himself as “highly supportive, but from the backseat.” He is active with and available to his students; however, it is essential that they are the ones driving the research. “Graduate students need to experience increasing amounts of autonomy but within a supportive framework that fades as they need to rely on it less and less as they become independent researchers,” he notes.

Intellectual growth, independence, and boldness

Hartwig shapes the intellectual maturation of his students. He believes that graduate school is not solely about results or publications, but about who students become in the process. 

“The most important output of a PhD program is not your results, your papers, or your thesis; it’s YOU,” he emphasizes. His mentorship is built around this philosophy, creating an environment where students steadily evolve into independent researchers.

Importantly, Hartwig cultivates a culture where bold, unconventional ideas are not just allowed – they’re encouraged. He models this approach through his own career, which has taken bold leaps across disciplines and technologies. “MIT should do things only MIT can do,” he tells his students. His message is clear: graduate students should not be afraid to go against the grain.

This philosophy has inspired many of his students to explore nontraditional research paths, armed with the confidence that failure is not a setback, but a sign that they are asking ambitious questions. Hartwig regularly reinforces this message, reminding students that null results and dead ends often teach us the most. 

“They’re the signposts you have to pass on the way to new territory,” he says.

Ultimately, one of the most fulfilling parts of Hartwig’s work is witnessing the moment when it all “clicks” for a student—when they begin to lead boldly, push back thoughtfully, and take true ownership of their research. “It’s a beautiful thing when it happens,” he reflects. For Hartwig, mentorship is about fostering not only the skills of a scientist, but the identity of one. His students don’t just grow in knowledge, they grow in courage, conviction, and clarity.