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[项目新闻] [BOINC] [物理类] LHC@Home

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发表于 2010-5-13 13:30:40 | 显示全部楼层
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发表于 2010-8-22 15:10:49 | 显示全部楼层
Latest news from the LHC

Over the past two weeks the LHC operations team has focused on pushing the LHC’s performance into new territory in terms of stored beam power. Moving to 25 bunches per beam with almost nominal bunch intensities at the end of July implied operation with a stored energy in each beam of more than 1 MJ. This corresponds to the current record for stored beam energy in existing hadron accelerators (e.g. CERN’s SPS and Fermilab’s Tevatron) and it marks an energy regime where a sudden loss of beam or operational errors can result in serious damage to equipment: an energy of 1 MJ is sufficient to melt 2 kg of copper. Extreme care and a thorough optimization of all operational procedures are therefore required in making this important transition in the machine’s performance.


The focus of the past two weeks has been on optimizing the operational procedures and the machine protection systems, with the aim of gaining experience with the reliability and reproducibility of the operation of the machine at such a high stored beam energy. This effort also featured record results for the LHC performance in terms of delivered luminosity. For the first time the peak luminosity surpassed 4x1030 cm-2 s-1 and the total integrated luminosity delivered to the experiments passed the milestone of 1 inverse picobarn (1 pb-1 or 1000 nb-1) over the weekend 7-8 August.

In parallel the operations team conducted several tests for improving the LHC performance still further. The ramp speed of the magnets (the rate at which the electrical current can be changed in the LHC main dipoles) has been increased from 2 A/s to 10 A/s for the pre-cycle (without beam) of the magnet system. The ramp speed of 10 A/s has also been successfully tested for acceleration with beam, but the final implementation must wait until the LHC starts operation with bunch “trains”, in which the bunches of protons are grouped closely together, in contrast to the present operation with widely separated bunches. The faster ramp speed reduces significantly the minimum required time between two physics fills and therefore increases the overall machine performance in terms of integrated luminosity.

Another step towards higher luminosity occurred just recently, when the number of bunches in each beam was increased from 25 to 49 on Thursday 19 August. This will be followed by a change to operation with bunch trains in September. Operating the machine with bunch trains will open the door for increasing the total number of bunches in successive steps, so improving the LHC’s luminosity over the coming months by another factor of 10 to 100.



by CERN Bulletin

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发表于 2010-10-3 19:02:57 | 显示全部楼层
The latest from the LHC : Training for higher intensities
Three weeks of intense machine development were brought to a satisfactory conclusion on the night of 21 September with the final validation of the machine protection systems for operation with bunch trains. The machine is now ready to accept more and more trains of bunches.

LHC_Report_picture_image.png

On Wednesday 22 September, the first physics fill was made using bunch trains, with 3 trains of 8 bunches per beam, providing 16 pairs of colliding bunches per experiment. This fill was used to restart operation for physics both for the machine and for the experiments. On Thursday, the number of bunches was increased to 56 per beam, providing 47 colliding pairs at Points 1, 5 and 8, and a smaller number at Point 2 to meet the requirements of ALICE. This is roughly the same intensity that we had in the machine in August. The first fill made under these conditions, fill 1366, brought an unexpected bonus. Bunches of nominal intensity were injected into the LHC with a smaller than usual transverse size, which was expected to cause lifetime problems when they were brought into collision. On the contrary, however, the beam lifetime in collision remained surprisingly high (25 hours) and the luminosity was significantly higher than expected. This opens up unexpected possibilities for the way that the machine is operated in future.

The strategy for increasing the intensity is to make an initial step of around 50 bunches, and then make 3 fills delivering over 20 hours of colliding beams under these conditions before progressing to the next step.

This first step was made on 25 September, with an increase to 104 bunches per beam, providing 93 colliding pairs at Points 1, 5 and 8. This means that the total intensity per beam now exceeds 1013
protons, and the stored energy per beam at 3.5TeV is 6MJ. With these levels of stored energy, the LHC is now operating with the highest stored beam energy of any collider, exceeding the record set by the ISR many years ago. Under these conditions the LHC is able to deliver over 1pb-1
luminosity in a 12-hour physics fill.

As the total intensity increases, many accelerator systems have to adapt to the higher intensities. This week, beam instrumentation and radio frequency systems started to show different behaviour and need to be tuned for the new conditions.

The next increase (to 152 bunches per beam) was made on Wednesday 30 September, with a further increase scheduled over the weekend. The peak luminosity to date is just under 5 1031
cm-2
s-1, which is within a factor 2 of the target for 2010.
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发表于 2011-12-5 12:19:03 | 显示全部楼层
没有大能翻译下吗?大意也行啊!
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发表于 2013-10-24 09:26:35 | 显示全部楼层
本帖最后由 zzfwind2007 于 2013-10-24 09:29 编辑

2013.10.23

http://lhcathomeclassic.cern.ch/sixtrack/forum_thread.php?id=3782
Problems
Sorry for the upload problems. Hope somebody here will
fix this soon. (I thought we had a new record number
of WUs in progress! :-) Eric.

上传有问题,希望有人能及时修复。(可能是任务个数破纪录了。)




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发表于 2013-10-24 21:10:47 | 显示全部楼层
2013.10.24

http://lhcathomeclassic.cern.ch/sixtrack/forum_thread.php?id=3783

Problem October 23rd Fixed

The permissions on the directory for the logs was wrong.
Corrected and results being uploaded. A fuller report and
a new Status and Plans will be issued soonest.


10月23日的上传错误已修复

大意:之前日志目录的权限出错,现已修复,能正常上传。
详细报告、最新状态和计划会尽早发布。

Google翻译

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发表于 2014-11-2 20:34:10 | 显示全部楼层
2014-10-31: LHC@Home Classic, Heavy I/O on Windows WUs
2014-10-31:LHC@Home Classic,在Windows平台上的以"w-"开头的任务包会导致严重的硬盘负担。但据调查,返回的结果均能通过验证。

It sems WUs with names beginning w-.... are creating a bit
much I/O for Windows. Under investigation, but the results
are good and are required. Thanks. Eric.
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发表于 2016-12-6 03:05:24 | 显示全部楼层
http://lhcathomeclassic.cern.ch/sixtrack/forum_thread.php?id=4002




As part of consolidation of LHC@home, we have setup a new server web front end using SSL for this project. The new URL is:

https://lhcathome.cern.ch/lhcathome

Please feel free to connect to the new site at your convenience. (BOINC 7.2 clients and later supports SSL.)

The old LHC@home classic site will continue operation as long as required. Currently there are no new Sixtrack tasks in the queue, but soon more applications and work will be available from this project.



--------------------------


Are https://lhcathome.cern.ch/lhcathome/ and http://lhcathomeclassic.cern.ch/sixtrack/index.php are really the same project ?

Should we redirect the normal Sixtrack-Project-Clients to this new URL ?

Are both URL spotting out work at the moment ?

Could we already make the change on the clients or better stay untouch until you tell us to switch .
egarding message-boards: At Atlas Forum we are used to see threads, that we already get noticed about new tasks, in green background instead in gray / white. Could you add this here please.

>>

Yes, it is the same project, with the same DB back-end. Tasks and credit as well as messages all go into the same place. The SSL project runs a later BOINC version, though.

2. If you have a recent (7.2 or later) BOINC client, yes, please detach and re-attach to the project at some convenient time. (This is what I have done with my Linux client.)

3 and 4, see above.

5. Thanks for the feedback, we'll work to improve the layout.
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发表于 2017-12-5 23:30:23 | 显示全部楼层
2017-12-05: LHC@Home, BOINC server update Thursday

We will upgrade the LHC@home web servers to the new BOINC server code with the "Bootstrap" theme on Thursday 7 December. The new style and layout can already be seen on the LHC@home development project..

During the intervention, from 09 UTC on Thursday, there may be intermittent availability of the LHC@home servers, so BOINC clients may back off and try to upload data later.



---
2017.12.05 本周四升级服务器
计划于本周四升级LHC的web服务器,从周四09:00 UTC开始,服务器将出现暂时性的抽风,各位算友请淡定。

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发表于 2017-12-14 23:36:21 | 显示全部楼层
2017-12-13: LHC@Home, Missing accounts

Due to a too aggressive spam-cleaning campaign (our fault), we have accidentally deleted some valid accounts on Monday. We have restored a backup copy of the BOINC database, and will recover the missing account data.

If you get a message "missing account key" from your BOINC client, you may be affected. We expect that we can fix this later today, once we have verified the data sets. Hence there is no need to register again.

My apologies for this mishap.



------------------
2017.12.13 用户信息丢失
本周一,由于服务器执行了一次过于严格的冗余信息清理,我们不小心删除了一些正常账户的账户信息。我们从BOINC 数据库中恢复了近期的一次备份,所以很快就能够丢失的用户信息。

如果你在BOINC 客户端中收到了“missing account key”消息,你可能就是在此次事故中受到影响的账户之一。我们有望今天晚些时候修复完毕。不需要重新注册。

再次向大家说声抱歉。

https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=4537
============================
2017-12-14: LHC@Home, Increased file server capacity

Since Tuesday evening, we have had intermittent issues with upload failures due to a combination of a large number of new hosts running BOINC that co-incidentally joined at the same time as larger ATLAS tasks had been introduced. Our file server capacity has been increased and backlog tasks waiting for upload should upload again soon. (Please refer to the ATLAS application and Number crunching forums for more details.)


2017.12.14 增加了文件服务器负载能力

周二晚上, 我们出现了断断续续的上传错误。这次问题的原因是大量新加入BIONC 的客户端偶然间同时加入到项目中,而此时lager ATLAS 任务也正好刚上线。我们的文件服务器负载能力现在已经得到改善,等待上传的任务现在应该可以正常上传了。()

https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=4539
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发表于 2018-1-8 20:34:21 | 显示全部楼层
2018-01-08: LHC@Home, File upload issues

Our NFS storage backend got saturated and hence uploads are failing intermittently.

The underlying cause is an issue with file deletion, we are trying to resolve that.

Sorry for the trouble and thanks for your patience with transfers to LHC@home.


---------
2018.01.08 文件上传问题
我们的NFS存储后端负载达到了饱和,由此导致了间歇性的上传失败问题。
本次意外原因在于对文件的删除操作出现了问题,我们正努力解决。
我们对由此造成的困扰表示抱歉,感谢大家对我们的耐心。

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发表于 2018-2-23 10:55:23 | 显示全部楼层
2018-02-22: LHC@Home, CMS Job queue draining

Due to a problem with the WMAgent submission task, a new batch of CMS jobs is not being put in the Condor queue. So, the queue is now draining and there will be no more jobs available in a couple of hours. Best to set your BOINC instance to No New Tasks if you can, to avoid spurious compute error terminations.

2018.02.22 CMS任务短缺
由于WMAgent submission task问题,新一批的CMS子项目任务没有被添加到派发队列中。所以现在任务队列已接近枯竭,近几个小时内不会有更多的新任务。建议各位先在BOINC中将项目设置为“不再接受新任务”,以防止出现假的计算错误。

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发表于 2018-2-28 20:44:10 | 显示全部楼层
2018-02-27: LHCathome-dev, ATLAS load tests

For information: We have increased limits pr. host on the dev project as part of a campaign to test our new storage backend.

Expect most new ATLAS tasks to be pulled by our local cluster hosts and the LCG cluster in Bejing. But there are tasks for other applications too for those interested. There might be interruptions too, as this is our development and testbed. :-)



-----------
2018.02.27 LHC@home-dev 项目,ATLAS负载测试
测试内容:放宽了对主机(host)任务数量的限制以测试新的存储后端
下一句看不懂。。

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发表于 2018-3-14 21:29:10 | 显示全部楼层
2018-03-14: LHC@Home, Theory application reaches 4 TRILLION events today !!

LHC@home's Theory application today passed the milestone of 4 TRILLION simulated events. This project, under its earlier name "Test4Theory", began production in 2011 and was the first BOINC project to use Virtual Machine technology (based on CERN's CernVM system).

We will be publishing some more details for you on the LHC@home and CERN websites over the coming days. Here is a first release:

http://lhcathome.web.cern.ch/art ... s-4-trillion-events

Many thanks to all our volunteers for enabling this achievement !



https://lhcathome.cern.ch/lhcathome/forum_thread.php?id=4638
----------2018-03-14: LHC@Home, Theory 子项目今日达成四万亿次事件模拟!
LHC@home 项目的Theory 子项目(原Test4Theory),今天达成了四万亿次事件模拟的里程碑。该项目启动于2011年,是首个BOINC 平台上采用虚拟机技术(基于CREN 的CernVM 系统)的项目。
我们在接下来的几天里会在LHC@home 项目官网与CERN 官网为各位提供更多关于此事的消息。
在此奉上第一条报道:http://lhcathome.web.cern.ch/articles/test4theory/test4theory-tops-4-trillion-events
感谢所有为本次成就贡献了力量的志愿者们!


附图:
所以说,聪明的人头发少应该是没错的。。(摸了摸自己茂盛的头发,不知道是应该高兴还是悲哀。。



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发表于 2018-10-19 21:45:01 | 显示全部楼层

2018-10-19: LHC@Home, SixTrack news

Dear Volunteers,

In spite of the break and lack of simulation work things are moving behind the scenes! Most of the trackers have been busy with the preparation of and attendance to the HiLumi annual collaboration meeting. For instance:
* new scanning parameters for DA studies, to shed some light on open points concerning the different behavior of the two beams in the LHC:
https://indico.cern.ch/event/743 ... rVeken_phase_dp.pdf
* an update of DA results to the latest developments on HL-LHC optics:
https://indico.cern.ch/event/742 ... Collab_18102018.pdf

The collaboration meeting is the most important event of the large collaboration, led by CERN, that is designing and building the High-Luminosity upgrade of the LHC. This is not only a forum to present and discuss recent results, but also an event that inspires new ideas and studies. Therefore, we would like to announce that in few weeks we will be back to you, counting on your usual fantastic and essential support, to launch new simulation campaigns!

Stay tuned!

Alessio and Massimo, for the SixTrack team








---------
过于专业,放弃翻译。。


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