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Axel Huebl

@axccl.bsky.social
327 followers 265 following 170 posts

computational physicist • accelerates accelerator research at @berkeleylab.bsky.social • laser-plasma aficionado • PByte connoisseur • mostly memory BW bound • openPMD • sciency C++ & 🐍 • GPGPU since before it was cool • he/his • Dr. rer. nat. Dipl.-Phys.

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Axel Huebl @axccl.bsky.social · 21/04/2026
Super excited about our new #preprint led by Carl A. Lindstrøm et al. on their highly anticipated "Achromatic optics using nonlinear plasma lenses for beam-quality preservation between plasma-accelerator stages"! arxiv.org/abs/2604.17605
Working principle plot: interstage over 6 metersEnergy scaling of key parameters
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Axel Huebl @axccl.bsky.social · 26/02/2026
It's a bit sad how many web apps / UIs do not support running behind HTTP Basic Auth anymore :-S Often due to static paths and assets that do not forward the auth (probably to load balance these static assets).
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Axel Huebl @axccl.bsky.social · 16/01/2026
Are you one of the 10'000s of #CXX #Python developers using #pybind11? Do you care about great #autodocs and #autocompletion in #interactive workflows?
github.com
Call for maintainers · Issue #244 · sizmailov/pybind11-stubgen
I've started pybind11-stubgen when there were no good alternatives to make good enough stubs for pybind modules. As of today I don't have a C++ project that needs python bindings, so I'm a bit out ...
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Axel Huebl @axccl.bsky.social · 07/01/2026
Look at this #zenodo #openscience peeps, @vsoch.bsky.social created an awesome @github.com action for us 🤩 github.com/vsoch/zenodo...
github.com
GitHub - vsoch/zenodo-validator: GitHub Action to validate Zenodo JSON Metadata Files. 🛡️
GitHub Action to validate Zenodo JSON Metadata Files. 🛡️ - vsoch/zenodo-validator
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 20/11/2025
HPSFCon 2026 Call for Proposals are OPEN! 📄 🎤 Submit talks, discussions, lightning sessions, posters that are moving HPC forward 📅 Deadline: January 11, 2026 👉 Submit your proposal here: events.linuxfoundation.org/hpsf-confere... 💭 Learn more about what we are looking for: hpsf.io/blog/2025/hp...
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Randall Munroe @xkcd.com · 18/11/2025
Beam Dump xkcd.com/3168/
Comic. [Person with ponytail pointing at diagram while speaking to three other people] PERSON: If the emergency stop is activated, any riders on the waterslide will be diverted into the beam dump, a large graphite block which will safely absorb their momentum. [caption] We regretted hiring an accelerator physicist to design our water park.
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 18/11/2025
We’re so excited to share that HPSF has been recognized as the Best HPC Collaboration in the 22nd edition of the HPCwire Readers’ Choice Awards! 🏆 Thank you to everyone who voted for HPSF. We’re excited for what the future of HPC holds! hpsf.io/blog/2025/hp...
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 18/11/2025
HPSF 🤝 SC25 Come say hi at booth 6134!
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Axel Huebl @axccl.bsky.social · 16/11/2025
Flying to #SC25: come see us tomorrow morning at #ISAV25 and visit our @hpsf.bsky.social booth! I'll be at SC until Wed noon this year.
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Axel Huebl @axccl.bsky.social · 10/11/2025
We look forward to welcome #SC25 attendees for #ISAV25 on Sunday morning! Program: sc25.conference-program.com/session/?ses... Homepage: isav-workshop.github.io/2025/
sc25.conference-program.com
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Axel Huebl @axccl.bsky.social · 28/10/2025
Found my new favorite unit: bit flips / flop
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LBNL Accelerator Technology & Applied Physics @atap.lbl.gov · 17/10/2025
Our BELLA Center has accomplished the first characterization of a collimated muon beam using a laser-plasma accelerator, laying the groundwork for advanced imaging techniques far exceeding current technologies @BerkeleyLab @doescience @ENERGY Read more here
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Axel Huebl @axccl.bsky.social · 10/10/2025
Wow, 52 paper submissions for #hpc #apps in our #IPDPS26 track this year. Do you like to join our strong review committee? Please contact me :)
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Axel Visel @axelvisel.bsky.social · 02/10/2025
Starting in 15 minutes!
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 01/10/2025
Great news! The date & location is locked in for #HPSFCon 2026. Save the date: ➡️ HPSF Conference 📅 March 16-20, 2026 📍 Chicago, IL The 2nd annual HPSFCon will again bring together the brightest minds in high performance software. Stay tuned for CFP & registration details later this month.
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Spack @spackpm.bsky.social · 02/10/2025
Join us in Chicago in March, when we'll hold the second in-person Spack User Meeting in conjunction with HPSFCon 2026! Stay tuned for details! #hpc #hpsf #spack
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 24/09/2025
Missed our 4 day tutorial at ICPP? We've outlined the highlights in our latest blog ✏️ ✨ Read more about our work with Spack, Kokkos, and Trilinos: hpsf.io/blog/2025/hp...
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 18/09/2025
Working on performance portability, sustainability, or trust in software? HPSFCon sessions dive into these challenges and more. 👀 🎧 Watch them on demand: www.youtube.com/playlist?lis...
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European Commission @ec.europa.eu · 06/09/2025
🚀 Europe’s first exascale supercomputer is here! JUPITER, launched in Germany, is the EU’s most powerful system and fourth fastest worldwide. 100% powered by renewables, it has also ranked first in energy efficiency. It will boost AI, science, and climate research. Read more - europa.eu/!vcWBqW
A futuristic corridor inside a data center with rows of tall, blue-lit server racks on both sides. Text overlaid at the bottom reads "JUPITER Supercomputer: Europe enters the exascale supercomputing league." In the lower right corner, there is a logo of the European Commission.
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Henry Schreiner @henryiii.bsky.social · 20/08/2025
cibuildwheel π is out! (3.1.4). A few nice things, like --clean-cache, Android fixes, and new versions of things like CPython 3.14rc2. Note for iOS on GHA/Azure, you need macOS-14, Microsoft broke macOS-15 images for iOS (WRT CPython's test runner, anyway) github.com/pypa/cibuild...
github.com
Release v3.1.4 · pypa/cibuildwheel
✨ Add a --clean-cache command to clean up our cache (#2489) 🛠 Update Python to 3.14rc2 and other patch version bumps (#2542, #2556) 🛠 Update Pyodide to 0.28.2 (#2562, #2558) 🐛 Fix resolution with p...
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Axel Huebl @axccl.bsky.social · 09/08/2025
Please don't hate me, but I will publish a tiny proceedings paper in which I list a single CPU core not far from a full GPU, because I wanted to learn how bad/good our serial vectorization is before OpenMP and MPI parallelization. I also want to do the cardinal sin of benchmark presentation, ok?!
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 31/07/2025
We're looking forward to participating in the 2025 International Conference on Parallel Processing (ICPP) 🤓 We'll be having a hands on workshop showcasing an introduction to Performance Portable HPC Development with Spack, Kokkos, and Trilinos. See you there ✨ hpsf.io/blog/2025/hp...
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Axel Huebl @axccl.bsky.social · 31/07/2025
C++ std::simd (ok, std::datapar) is cool. Portable, order-of-magnitude speedups (w/ modern CPUs and the right, flop intense algorithms) 🚀 #HPC #SIMD github.com/BLAST-Impact...
github.com
CPU SIMD Support by ax3l · Pull Request #1002 · BLAST-ImpactX/impactx
todo See AMReX-Codes/amrex#4520 To Do update install docs update CI (partially): SIMD, ideally even single-precision (uncovers more issues at compile-time) Benchmarks on Dane (LLNL) Machine: Da...
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Glenn K. Lockwood @glennklockwood.com · 29/07/2025
The 13th MVAPICH User Group (MUG) Conference is coming up (Aug 18-20 in Columbus). It's a great event for focused technical presentations around MPI and network performance. Great speaker lineup too. Wish I could make it in-person, but virtual attendance is free mug.mvapich.cse.ohio-state.edu #HPC
mug.mvapich.cse.ohio-state.edu
MUG :: Home
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Spack @spackpm.bsky.social · 20/07/2025
💥Spack v1.0 is out!💥 This is a huge milestone. We reworked the core to add compiler dependencies, and we're introducing a stable package API. 🚀1.0 also adds concurrent builds, better includes, and much more -- read it all in the release notes! github.com/spack/spack/...
github.com
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hpc.social on BlueSky @hpc.social · 03/07/2025
New #HPC Job! 😍️ HPC Software Scientist: Mixed Precision in molecular dynamics / GROMACS Location: Stockholm, sweden Employer: KTH Royal Institute of Technology in Stockholm Remote: Remote friendly
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Axel Huebl @axccl.bsky.social · 04/07/2025
CfP: We are looking for talks/short/long papers to #ISAV 2025: In Situ AI, Analysis and Visualization! Are you working on in situ methods, algorithms or the synthesis between HPC & AI/ML? Share your best results as papers, your ideas as short papers or talks! #SC25 isav-workshop.github.io/2025/
isav-workshop.github.io
ISAV 2025: In Situ AI, Analysis and Visualization
Information for the SC’25 conference ISAV workshop
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Jessica Paquette @barrelshifter.bsky.social · 01/07/2025
computer still bad
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Jan Gray @jangray.bsky.social · 12/06/2025
Dread HPC Guru Roberts
Mashup of Dread Pirate Roberts from Princess Bride and the “I am HPC Guru” button
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HPC Guru @hpcguru.bsky.social · 11/06/2025
All things, with one exception, have to end After years of sharing #HPC news and insights, it's time to log off It was fun while it lasted and I remain grateful to all of you who followed and interacted Stay curious, stay kind! — @hpcguru.bsky.social signing off #HPC #Farewell
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Chanda Prescod-Weinstein 🌌 @chanda.blacksky.app · 11/06/2025
MAJOR PARTICLE PHYSICS REPORT RELEASE ⚛️🧪 The National Academies particle physics decadal report is out! Read read! (I was a member of the committee that wrote this report but resigned during drafting bc of a conflict of service w/my HEPAP appointment.) nap.nationalacademies.org/catalog/2883...
nap.nationalacademies.org
Elementary Particle Physics: The Higgs and Beyond
Read online, download a free PDF, or order a copy in print.
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 04/06/2025
HPSF 🤝 ISC 2025 Join us next week at ISC for tutorials, BoFs, and workshops on HPSF projects Spack, OpenCHAMI, and more. 🗓️ Details: hpsf.io/blog/2025/hp... #HPSF #ISC25 #ISChpc #ISC25_SCC #ConnectingTheDots
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Daniel S. Katz @danielskatz.org · 05/06/2025
A key milestone will be the expert workshop: Access to Research Software: Opportunities and Challenges taking place on 8 September 2025 at the OECD headquarters in Paris. To participate or contribute, please contact alan.paic@oecd.org (4/5)
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 30/05/2025
The inaugural High Performance Software Foundation Conference offered updates from HPSF projects, insights on processor & system trends, active discussions around the future of interoperability, and more. ▶️ Find our #HPSFCon recap and links to all the recordings at: hpsf.io/blog/2025/hp...
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Berkeley Lab @berkeleylab.lbl.gov · 29/05/2025
✨ Berkeley Lab's @nersc.bsky.social, @delltechnologies.bsky.social, and NVIDIA announce new public-private partnership for game-changing US Dept. of Energy Doudna supercomputer, (NERSC-10, strengthening U.S. capabilities, accelerating discovery, and powering future science. 🧪
newscenter.lbl.gov
DOE Announces New Supercomputer Powered by Dell and NVIDIA to Speed Scientific Discovery
The NERSC-10 system at Berkeley Lab will accelerate DOE Office of Science research in an era of rapidly advancing simulation, data, and AI capabilities.
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HPC Guru @hpcguru.bsky.social · 30/05/2025
NERSC-10 will be named Doudna: DOE awards contract to Dell for #supercomputer powered by NVIDIA’s next-generation Vera Rubin platform newscenter.lbl.gov/2025/05/29/d... #HPC #AI @nersc.bsky.social @cs.lbl.gov
newscenter.lbl.gov
DOE Announces New Supercomputer Powered by Dell and NVIDIA to Speed Scientific Discovery
The NERSC-10 system at Berkeley Lab will accelerate DOE Office of Science research in an era of rapidly advancing simulation, data, and AI capabilities.
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Michael Zingale @michaelzingale.bsky.social · 24/05/2025
new in pynucastro: we can now export to NetworkX and use their functions analyze a reaction network. Here's an example of finding cycles -- NetworkX finds the CNO and hot-CNO cycles in a network: pynucastro.github.io/pynucastro/n... #astro #astrocode
pynucastro.github.io
Finding Cycles (with NetworkX) — pynucastro 2.6.0.post10+g06c1c846 documentation
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v @vsoch.bsky.social · 24/05/2025
#HPC (as a developer) predominantly means trying to find strategies to get around limitations. You can't be root or completely control the environment. Your kernel or compiler is old. On a good day, it's still a few hours to get up the point of working to innovate on the thing you are interested in.
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David Aerne @meodai.bsky.social · 24/05/2025
No API docs should have physics. Its super distracting.
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Matt Godbolt @matt.godbolt.org · 23/05/2025
Experimenting with something like this for @compiler-explorer.com - wondering what your thoughts are? AI is getting everywhere, and can be divisive. I'm hoping something like this - so long as I can get the output quality high enough - is a net benefit to help folks learn more about their code.
A screenshot of Compiler Explorer showing an "AI Explain this" view. The source code is: 

bool isspc(char c) { 
    return c == '\n' || c == '\r' || c == '\t' || c == ' ';
}

The asm is:
isspc(char):
        mov     ecx, edi
        cmp     cl, 33
        setb    dl
        movabs  rax, 4294977024
        shr     rax, cl
        and     al, dl
        ret

Below is a "Claude Explain" window with:

The function isspc(char) is compiled to an efficient bit manipulation technique to check for whitespace characters. Let's break down the assembly instructions:

mov ecx, edi

Copies the input character from the edi register (first function argument) to ecx
cl will contain the lowest 8 bits (the character)
cmp cl, 33

Compares the character against decimal 33
This is a preliminary check to quickly filter out non-whitespace characters
setb dl

Sets the dl register to 1 if the character is below 33 (space, tab, newline, etc.)
Uses a conditional set instruction
movabs rax, 4294977024

Loads a pre-computed 64-bit constant
This constant represents a bit mask for whitespace detection
shr rax, cl

Shifts the bit mask right by the character's value
This dynamically positions the mask based on the input character
and al, dl

Performs a bitwise AND between the shifted mask and the previous condition
Produces the final boolean result in al
ret

Returns the result (0 or 1) in al
This implementation is a highly optimized branchless method for checking whitespace characters, using bit manipulation instead of multiple comparisons. It avoids conditional jumps, which can be slower on modern CPUs.

The code checks for space (' '), newline ('\n'), carriage return ('\r'), and tab ('\t') in a single, efficient operation.
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HPC Guru @hpcguru.bsky.social · 22/05/2025
LLNL’s Center for Applied Scientific Computing (CASC) has developed a new JIT approach that leverages LLVM intermediate representation (IR) to optimize #GPU kernels at runtime computing.llnl.gov/about/newsro... #HPC #AI
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Verónica MV (she/ella) @verolero86.bsky.social · 22/05/2025
📣 The 2026 INCITE Call for Proposals is open through June 16! The INCITE program supports groundbreaking research 🧪🔭🧬 requiring extreme-scale computing and awards allocations on Exascale systems including OLCF's #Frontier and ALCF's #Aurora 📝 More details: bit.ly/3VjoEhX #HPC #AI
The world INCITE written with letters filled with molecules visualization. Includes caption advertising the Call for Proposals closes June 16
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HPC Guru @hpcguru.bsky.social · 20/05/2025
Announcing the 44 Accepted #SC25 Workshops o Workshops with Proceedings o Symposium-style Workshops sc25.supercomputing.org/2025/05/anno... #HPC
sc25.supercomputing.org
Announcing the 44 Accepted SC25 Workshops • SC25
SC25 has accepted 33 workshops to which you may submit a paper for possible publication. Eleven workshops are symposium-style.
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Freya Blekman @freyablekman.bsky.social · 17/05/2025
I'm recruiting a PhD student to work on CMS, with a focus on substructure/BSM in four-top final states/CMS HGCAL: inspirehep.net/jobs/2921389 (all details in link)
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Victor Mateevitsi @vmateevitsi.com · 14/05/2025
Honored to be named a Vanguard of HPC + AI by insideHPC. At Argonne’s ALCF, I get to explore how humans and machines collaborate—through XR, in-situ viz, and tools that bring data to life. Dancing on the bleeding edge of science—and loving every step. insidehpc.com/2025/05/vang...
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 07/05/2025
HPSF Conference Day 3️⃣ starts off with a bang 🧨 Today's #HPSFCon agenda features in-depth sessions for several HPSF project communities including: 🎇 AMReX 🎇 Apptainer 🎇 Charliecloud 🎇 Kokkos 🎇 Spack 🎇 Trilinos
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High Performance Software Foundation (HPSF) @hpsf.bsky.social · 02/05/2025
We're looking forward to HPSFCon next week with more than 130 speakers on the most pressing high performance software topics 🔥 Featured panels include: 👥 Status and Trends in the HPC Landscape 👥 Processor Trends and What They Mean for Software Join us in Chicago to be part of the conversation!
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Axel Huebl @axccl.bsky.social · 23/04/2025
Pro tip: even on #conda-forge, CI/CD ain't no beauty contest. (RE: disabling tests/entries w/o opening an issue to track.)
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