Jack Hare
@jdhare.bsky.social
Assistant professor at Cornell ECE and the Laboratory of Plasma Studies. I'm a plasma physicist, and PI of puffin.ece.cornell.edu . I'm interested in laboratory astrophysics and nuclear fusion using pulsed-power. ️🌈, he/him.
I'm packing for APS DPP in Long Beach Ca tomorrow, which includes the most vital item for any US conference: half decent tea bags!
November 15, 2025 at 5:52 PM
I'm packing for APS DPP in Long Beach Ca tomorrow, which includes the most vital item for any US conference: half decent tea bags!
A grad student is 3D printing a scale model of PUFFIN, but it comes out with these terrifying eldritch trees as support structures. Very disturbing.
November 14, 2025 at 7:36 PM
A grad student is 3D printing a scale model of PUFFIN, but it comes out with these terrifying eldritch trees as support structures. Very disturbing.
Reposted by Jack Hare
Wait, your lab doesn't have a popcorn maker? That sounds unbearable.
November 13, 2025 at 8:25 PM
Wait, your lab doesn't have a popcorn maker? That sounds unbearable.
Wait, your lab doesn't have a popcorn maker? That sounds unbearable.
November 13, 2025 at 8:25 PM
Wait, your lab doesn't have a popcorn maker? That sounds unbearable.
For the last few years I've made an overview poster for the APS Division of Plasma Physics, featuring the work done in my group over the last 12 months. It's a great opportunity to look back and see what we've achieved, and a good source of material for future talks!
November 12, 2025 at 6:47 PM
For the last few years I've made an overview poster for the APS Division of Plasma Physics, featuring the work done in my group over the last 12 months. It's a great opportunity to look back and see what we've achieved, and a good source of material for future talks!
Somewhere up above there's a stunning aurora! Shame about the thick clouds...
November 12, 2025 at 2:11 AM
Somewhere up above there's a stunning aurora! Shame about the thick clouds...
A very cool experiment in extreme laboratory plasma astrophysics!
New in PNAS: we recreated blazar pair cascades in the lab. Using CERN’s Super Proton Synchrotron, we produced dense electron–positron beams and sent them through plasma to test whether beam instabilities can disrupt them, they can’t.
@ox.ac.uk @cern.bsky.social @golp-ist.bsky.social
@ox.ac.uk @cern.bsky.social @golp-ist.bsky.social
Suppression of pair beam instabilities in a laboratory analogue of blazar pair cascades | PNAS
The generation of dense electron–positron pair beams in the laboratory can enable
direct tests of theoretical models of γ-ray bursts and active gal...
www.pnas.org
November 8, 2025 at 12:38 PM
A very cool experiment in extreme laboratory plasma astrophysics!
It was great to be back at MIT PSFC! Yesterday I packed most of my old lab, ready to move to Cornell and sat on the cmte for Zhou Lou's defense, and today I gave the PSFC seminar and caught up all my colleagues. Here I am with students old and current, and some new PUFFIN stickers!
November 8, 2025 at 1:14 AM
It was great to be back at MIT PSFC! Yesterday I packed most of my old lab, ready to move to Cornell and sat on the cmte for Zhou Lou's defense, and today I gave the PSFC seminar and caught up all my colleagues. Here I am with students old and current, and some new PUFFIN stickers!
Another great fusion milestone - I had just arrived at MIT when the TFMC was tested in 2021, and now CFS has ramped up a production line to build the full-scale toroidal field magnets needed for SPARC. Very impressive engineering!
It’s a great moment to celebrate milestones at CFS — in more ways than one. Today we announced we’re done manufacturing one of our key magnets and putting it through a rigorous, month-long battery of performance tests — which it passed. 1/4
#PowerMoves
#PowerMoves
September 30, 2025 at 2:21 PM
Another great fusion milestone - I had just arrived at MIT when the TFMC was tested in 2021, and now CFS has ramped up a production line to build the full-scale toroidal field magnets needed for SPARC. Very impressive engineering!
Some really interesting results from Zap! I'm a long term Z-pinch enthusiast, and these results represent a solid technical development. Now we need the physics proof that shear flow stabilisation can really enable Q>1!
Century, Zap’s fusion technology test platform, has set a new performance record, operating at 39 kW average power for a series of >100 plasma shots at 0.2 Hz (one every 5 sec), with the resulting heat captured by circulating liquid metal. www.zapenergy.com/news/lightni...
Lightning Strikes 12 Times Per Minute on Zap Energy’s Century Platform
Achievement of 39 kilowatt average power operations marks twenty-fold progress in enabling technologies for Z-pinch fusion power plant
www.zapenergy.com
September 30, 2025 at 2:00 PM
Some really interesting results from Zap! I'm a long term Z-pinch enthusiast, and these results represent a solid technical development. Now we need the physics proof that shear flow stabilisation can really enable Q>1!
I'm on the sorting committee for the APS DPP conference this year, and boy is there a lot of behind the scenes work to get talks and posters sorted into sessions. Feel free to curse me when you're sprinting back and forth across a giant conference venue to make to every talk this Fall!
August 6, 2025 at 6:51 PM
I'm on the sorting committee for the APS DPP conference this year, and boy is there a lot of behind the scenes work to get talks and posters sorted into sessions. Feel free to curse me when you're sprinting back and forth across a giant conference venue to make to every talk this Fall!
Kinda interesting, but get back to me when they evolve Q-switching.
Peacocks have a secret hidden in their brightly colored tail feathers: tiny reflective structures that can amplify light into a laser beam. scim.ag/3UEM2oQ
Peacock feathers can be lasers
Tail feathers can emit narrow beams of light, a first in the animal kingdom
scim.ag
July 31, 2025 at 4:04 PM
Kinda interesting, but get back to me when they evolve Q-switching.
The neon calibration lamp makes our experiment look very threatening.
July 19, 2025 at 6:05 PM
The neon calibration lamp makes our experiment look very threatening.
Reposted by Jack Hare
Here's the thing: If I added invisible text to my manuscript offering a prayer to Glykon, the serpent god of hoax deities, it would obviously have no effect on the review because Glykon does not screen manuscripts.
Publishers using AI is a publisher problem.
Praise Glykon.
Publishers using AI is a publisher problem.
Praise Glykon.
It’s academic dishonesty on both sides. How is adding invisible text to game a LLM any different from P-hacking?
Either your evidence stands on its own or it doesn’t.
And science has suffered from far too many who only publish the party line to appease reviewers who don’t want to be contradicted.
Either your evidence stands on its own or it doesn’t.
And science has suffered from far too many who only publish the party line to appease reviewers who don’t want to be contradicted.
July 15, 2025 at 3:02 PM
Here's the thing: If I added invisible text to my manuscript offering a prayer to Glykon, the serpent god of hoax deities, it would obviously have no effect on the review because Glykon does not screen manuscripts.
Publishers using AI is a publisher problem.
Praise Glykon.
Publishers using AI is a publisher problem.
Praise Glykon.
I've seen some people say it is unethical to sneak a prompt into a manuscript sent for review. It's unclear to me how this is unethical - only those reviewers using LLMs for peer review (a deeply unethical thing to do) would fall foul to it!
Researchers have been sneaking secret messages into their papers in an effort to trick AI tools into giving them a positive peer-review report
Read the full story: www.nature.com/articles/d41...
Read the full story: www.nature.com/articles/d41...
July 15, 2025 at 4:39 PM
I've seen some people say it is unethical to sneak a prompt into a manuscript sent for review. It's unclear to me how this is unethical - only those reviewers using LLMs for peer review (a deeply unethical thing to do) would fall foul to it!
Reposted by Jack Hare
Researchers have been sneaking secret messages into their papers in an effort to trick AI tools into giving them a positive peer-review report
Read the full story: www.nature.com/articles/d41...
Read the full story: www.nature.com/articles/d41...
July 15, 2025 at 1:48 PM
Researchers have been sneaking secret messages into their papers in an effort to trick AI tools into giving them a positive peer-review report
Read the full story: www.nature.com/articles/d41...
Read the full story: www.nature.com/articles/d41...
Back in the lab for two weeks of experiments on COBRA with this (for now) beautiful hardware! More experiments on guide field reconnection this time with Thomson scattering measurements.
July 15, 2025 at 12:40 AM
Back in the lab for two weeks of experiments on COBRA with this (for now) beautiful hardware! More experiments on guide field reconnection this time with Thomson scattering measurements.
Our lab techs complain that we pay them peanuts. This is outright slander: we pay them in U.S. fancy peanuts.
July 7, 2025 at 1:30 PM
Our lab techs complain that we pay them peanuts. This is outright slander: we pay them in U.S. fancy peanuts.
Reposted by Jack Hare
Now on @sciam.bsky.social: Breakthrough results from two rival experimental reactors—the Wendelstein 7-X stellarator and the Joint European Torus tokamak—offer hope that the elusive dream of fusion power is within reach.
www.scientificamerican.com/article/reco...
www.scientificamerican.com/article/reco...
Record-Breaking Results Bring Fusion Power Closer to Reality
Breakthroughs from two rival experiments, Germany’s Wendelstein 7-X and the Joint European Torus, suggest the elusive dream of controlled nuclear fusion may be within reach
www.scientificamerican.com
July 3, 2025 at 1:29 PM
Now on @sciam.bsky.social: Breakthrough results from two rival experimental reactors—the Wendelstein 7-X stellarator and the Joint European Torus tokamak—offer hope that the elusive dream of fusion power is within reach.
www.scientificamerican.com/article/reco...
www.scientificamerican.com/article/reco...
Requesting more free computer money to pay the computer for more plasma simulations. Maybe this time we can fix our dodgy boundary conditions!
July 2, 2025 at 12:57 PM
Requesting more free computer money to pay the computer for more plasma simulations. Maybe this time we can fix our dodgy boundary conditions!
This is a simplification; the whole process becomes much more complex when you consider the gyro motion and the gxB drift! :D
May 19, 2025 at 8:17 PM
This is a simplification; the whole process becomes much more complex when you consider the gyro motion and the gxB drift! :D
I had a quick tour this morning of the incredible space which used to house Cornell's nuclear reactor. Look at the bridge crane! The control room! The smashed concrete where the reactor used to sit!
May 16, 2025 at 5:42 PM
I had a quick tour this morning of the incredible space which used to house Cornell's nuclear reactor. Look at the bridge crane! The control room! The smashed concrete where the reactor used to sit!
The triple product is a flawed metric for fusion - one can't have a 100 eV plasma at higher density and get the same fusion performance as a 10 keV plasma at 100x lower density. Fusion requires high temperatures - temperature and density are not interchangeable, only density and confinement time.
Plasmas must meet three conditions for fusion to occur, including reaching sufficient temperature, density, and time. Together, these factors comprise what is known as the Lawson criterion, or the triple product. Learn more here: #fusionenergy #fusionenergyweek
The Science of Fusion
Where the triple product reigns supreme.
usfusionenergy.org
April 23, 2025 at 7:29 PM
The triple product is a flawed metric for fusion - one can't have a 100 eV plasma at higher density and get the same fusion performance as a 10 keV plasma at 100x lower density. Fusion requires high temperatures - temperature and density are not interchangeable, only density and confinement time.
Reposted by Jack Hare
This morning I toured the Cornell High Energy Synchotron Source (CHESS) with my colleagues from the Cornell Laboratory of Plasma Studies. Here we are in the control room, with a delightful range of instruments dating back to the 1960s.
April 15, 2025 at 9:16 PM
This morning I toured the Cornell High Energy Synchotron Source (CHESS) with my colleagues from the Cornell Laboratory of Plasma Studies. Here we are in the control room, with a delightful range of instruments dating back to the 1960s.