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Aussie Aussie Aussie! Oi! Oi! Oi! Summer Solstice Challenge

PrimeGrid - Po, 09.12.2019 - 00:15
The longest day of the year (in the southern hemisphere!) is drawing near, and to mark this turning point in the year, PrimeGrid is offering a 10-day challenge on the GFN-21, GFN-22, and GFN-DYFL subprojects. Will you be the first to discover a prime in one of these so-far unlucky categories? The challenge will run from December 12th 04:19:00 UTC until December 22nd 04:19:00 UTC. For more information, questions and general banter and merry making please join us on the forums at https://www.primegrid.com/forum_thread.php?id=8916.
Kategórie: Novinky z projektov

New paper on observing "Clarke Exo-belts"

SETI@Home - St, 04.12.2019 - 21:44
Dr. Korpela and his colleagues Prof. Shauna Sallmen and Ms. Kaisa Crawford-Taylor have published a new paper today in the Astronomical Journal about whether astronomers be able to detect belts of satellites circling planets around other stars. Unfortunately, the answer is that even the thickest satellite belts will be very difficult to see with current technology. Even the James Webb Space Telescope will find it difficult.

If, like most sentient beings in the Galaxy, you don't have a subscription to the Astronomical Journal you can see a preprint of the article at arXiv.org.
Kategórie: Novinky z projektov

Position Open: Challenge Coordinator

PrimeGrid - St, 04.12.2019 - 15:10
PrimeGrid is looking for someone to coordinate our BOINC challenges. The challenge coordinator sets the schedule, creates the theme for each challenge, and communicates with the PrimeGrid community. Reply to me via PM or respond here if you're interested or have questions.
Kategórie: Novinky z projektov

Disk full

GPUGRID - Ne, 01.12.2019 - 14:02
I am aware of it and working to solve. No need to abort your workunits. I'm stopping the project in the meantime.
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Fall/Winter 2019 Funding drive has started

SETI@Home - Pi, 29.11.2019 - 00:00
We've started our 2019 funding drive. Many of you have probably received our email penned by Jeff Cobb who has been in the SETI group longer than I have. If you can't wait, you can read yours here.

Because of our continued effort to be GDPR compliant, we're not sending emails to anyone with an EU/EAA email addresses, anyone who listed an EU/EAA country, or anyone who listed "International" as their country. And, of course, anyone who has opted out of our emails won't get them.

Thanks for your support!
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New SETI Perspectives: "Is ET in Our Solar System?"

SETI@Home - St, 27.11.2019 - 06:43
Richard Lawn has posted a new SETI Perspectives entitled "Is ET in Our Solar System?"
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Thanks for supporting SixTrack at LHC@Home and updates

LHC@home - Ut, 23.01.2018 - 19:08
Dear volunteers,

All members of the SixTrack team would like to thank each of you for supporting our project at LHC@Home. The last weeks saw a significant increase in work load, and your constant help did not pause even during the Christmas holidays, which is something that we really appreciate!

As you know, we are interested in simulating the dynamics of the beam in ultra-relativistic storage rings, like the LHC. As in other fields of physics, the dynamics is complex, and it can be decomposed into a linear and a non-linear part. The former allows the expected performance of the machine to be at reach, whereas the latter might dramatically affect the stability of the circulating beam. While the former can be analysed with the computing power of a laptop, the latter requires BOINC, and hence you! In fact, we perform very large scans of parameter spaces to see how non-linearities affect the motion of beam particles in different regions of the beam phase space and for different values of key machine parameters. Our main observable is the dynamic aperture (DA), i.e. the boundary between stable, i.e. bounded, and unstable, i.e., unbounded, motion of particles.

The studies mainly target the LHC and its upgrade in luminosity, the so-called HL-LHC. Thanks to this new accelerator, by ~2035, the LHC will be able to deliver to experiments x10 more data than what is foreseen in the first 10/15y of operation of LHC in a comparable time. We are in full swing in designing the upgraded machine, and the present operation of the LHC is a unique occasion to benchmark our models and simulation results. The deep knowledge of the DA of the LHC is essential to properly tune the working point of the HL-LHC.

If you have crunched simulations named "workspace1_hl13_collision_scan_*" (Frederik), then you have helped us in mapping the effects of unavoidable magnetic errors expected from the new hardware of the HL-LHC on dynamic aperture, and identify the best working point of the machine and correction strategies. Tasks named like "w2_hllhc10_sqz700_Qinj_chr20_w2*" (Yuri) focus the attention onto the magnets responsible for squeezing the beams before colliding them; due to their prominent role, these magnets, very few in number, have such a big impact on the non-linear dynamics that the knobs controlling the linear part of the machine can offer relevant remedial strategies.

Many recent tasks are aimed at relating the beam lifetime to the dynamic aperture. The beam lifetime is a measured quantity that tells us how long the beams are going to stay in the machine, based on the current rate of losses. A theoretical model relating beam lifetime and dynamic aperture was developed; a large simulation campaign has started, to benchmark the model against plenty of measurements taken with the LHC in the past three years. One set of studies, named "w16_ats2017_b2_qp_0_ats2017_b2_QP_0_IOCT_0" (Pascal), considers as main source of non-linearities the unavoidable multipolar errors of the magnets, whereas tasks named as "LHC_2015*" (Javier) take into account the parasitic encounters nearby the collision points, i.e. the so called "long-range beam-beam effects".

One of our users (Ewen) is carrying out two studies thanks to your help. In 2017 DA was directly measured for the first time in the LHC at top energy, and nonlinear magnets on either side of ATLAS and CMS experiments were used to vary the DA. He wants to see how well the simulated DA compares to these measurements. The second study seeks to look systematically at how the time dependence of DA in simulation depends on the strength of linear transverse coupling, and the way it is generated in the machine. In fact, some previous simulations and measurements at injection energy have indicated that linear coupling between the horizontal and vertical planes can have a large impact on how the dynamic aperture evolves over time.

In all this, your help is fundamental, since you let us carry out the simulations and studies we are interested in, running the tasks we submit to BOINC. Hence, the warmest "thank you" to you all!
Happy crunching to everyone, and stay tuned!

Alessio and Massimo, for the LHC SixTrack team.
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LHC@home down-time due to system updates

LHC@home - Ut, 23.01.2018 - 11:19
Tomorrow Wednesday 24/1, the LHC@home servers will be unavailable for a short period while our storage backend is taken down for a system update.

Today, Tuesday 23/1, some of the Condor servers that handle CMS, LHCb and Theory tasks will be down for a while. Regarding the on-going issues with upload of files, please refer to this thread.

Thanks for your understanding and happy crunching!
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