Difference between revisions of "CERN Prototype Materials"

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= ARCHIVAL =
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= Select Documents and Meetings =
 
= Select Documents and Meetings =
 
* Current (2015)
 
* Current (2015)
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*** {{DocDB|10715|DocDB 10715}}: The text of the proposal
 
*** {{DocDB|10715|DocDB 10715}}: The text of the proposal
 
*** {{DocDB|11188|DocDB 11188}}: Presentation slides for the proposal
 
*** {{DocDB|11188|DocDB 11188}}: Presentation slides for the proposal
 
 
* History (2014)
 
* History (2014)
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** {{DocDB|9905|DocDB 9905}}: Meeting 10/29/2014.
 
** {{DocDB|9413|DocDB 9413}}: Expression of Interest.
 
** {{DocDB|9413|DocDB 9413}}: Expression of Interest.
 
** {{DocDB|8816|DocDB 8816}}: A collection of meeting materials.
 
** {{DocDB|8816|DocDB 8816}}: A collection of meeting materials.
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*** [http://laguna.ethz.ch/indico/conferenceOtherViews.py?view=standard&confId=83 LAGUNA/LBNO-Demo meeting (WA105 kickoff)] - see the software session
 
*** [http://laguna.ethz.ch/indico/conferenceOtherViews.py?view=standard&confId=83 LAGUNA/LBNO-Demo meeting (WA105 kickoff)] - see the software session
 
*** [http://laguna.ethz.ch:8080/Plone/wa105/proposal-for-large-scale-neutrino-detectors-prototyping-and-phased-performance-assessment-in-view-of-a-long-baseline-oscillation-experiment/view WA105 Proposal to CERN SPSC]
 
*** [http://laguna.ethz.ch:8080/Plone/wa105/proposal-for-large-scale-neutrino-detectors-prototyping-and-phased-performance-assessment-in-view-of-a-long-baseline-oscillation-experiment/view WA105 Proposal to CERN SPSC]
 
 
* History (2013)
 
* History (2013)
 
** [http://indico.cern.ch/event/282315/material/slides/1?contribId=0 Outline of early CERN plans for WA104/WA105]
 
** [http://indico.cern.ch/event/282315/material/slides/1?contribId=0 Outline of early CERN plans for WA104/WA105]
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Let's assume we want to measure a signal with 5% precision and signal to background ratio is 1:10. To provide this scale of accuracy, we will need ~10<sup>5</sup> events in the momentum bin of interest.
 
Let's assume we want to measure a signal with 5% precision and signal to background ratio is 1:10. To provide this scale of accuracy, we will need ~10<sup>5</sup> events in the momentum bin of interest.
 
= Appendix III =
 
 
 
== DAQ references ==
 
* ATLAS
 
** [http://iopscience.iop.org/1742-6596/331/2/022007/pdf/1742-6596_331_2_022007.pdf ATLAS TDAQ dataflow in Run 1]
 
Note: some of these links may be restricted to users associated with respective LHC experiments. This will be resolved at a later date (i.e. relevant and public information extracted, reduced and systematized).
 
 
== Data Storage Links ==
 
=== General CERN Storage Info ===
 
* In early 2000s, the CASTOR system was deployed at CERN which provides front-end to mass storage, in the form of both tape and disk pools. In early 2010s, the disk pools were largely migrated to EOS, a newer and high-performance system based on XRootD which has better functionality for managing large disk pools. CASTOR is still used for custodial data on tape.
 
* [http://iopscience.iop.org/1742-6596/396/4/042030/pdf/1742-6596_396_4_042030.pdf Overview of LHC storage operations at CERN]
 
* [http://castor.web.cern.ch/ CASTOR]
 
 
* [https://twiki.cern.ch/twiki/bin/view/FIOgroup/TsiSection Technology and Storage Infrastructure group at CERN]
 
* '''CDR (Central Data Recording, not to be confused with Conceptual Design Report)'''
 
** [https://twiki.cern.ch/twiki/bin/view/DSSGroup/TabCdr Apparently '''main''' CDR wiki]
 
** [https://twiki.cern.ch/twiki/bin/view/FIOgroup/CDR_Problem CDR Troubleshooting]
 
** [https://twiki.cern.ch/twiki/bin/view/FIOgroup/CDR_Config CDR Configuration]
 
** [https://twiki.cern.ch/twiki/bin/view/P326/CDR An older CDR configuration example]
 
 
=== EOS ===
 
* [http://eos.cern.ch/index.php?option=com_content&view=article&id=87:using-eos-at-cern&catid=31:general&Itemid=41 Setting up EOS]
 
* [https://cern.service-now.com/service-portal/article.do?n=KB0001998 Beginner's Tutorial] for EOS
 
** At CERN: source /afs/cern.ch/project/eos/installation/[atlas|cms|lhcb|alice]/etc/setup.sh
 
** Run "eos"
 
** Example: ls /eos/atlas/atlasdatadisk/rucio/data15_13TeV/ab/f4
 
* EOS list of commands:
 
<nowiki>
 
 
access              Access Interface
 
archive              Archive Interface
 
attr                Attribute Interface
 
backup              Backup Interface
 
clear                Clear the terminal
 
cd                  Change directory
 
chmod                Mode Interface
 
chown                Chown Interface
 
config              Configuration System
 
console              Run Error Console
 
cp                  Cp command
 
debug                Set debug level
 
dropbox              Drop box
 
exit                Exit from EOS console
 
file                File Handling
 
fileinfo            File Information
 
find                Find files/directories
 
fs                  File System configuration
 
fsck                File System Consistency Checking
 
fuse                Fuse Mounting
 
group                Group configuration
 
help                Display this text
 
io                  IO Interface
 
json                Toggle JSON output flag for stdout
 
license              Display Software License
 
ls                  List a directory
 
map                  Path mapping interface
 
mkdir                Create a directory
 
motd                Message of the day
 
node                Node configuration
 
ns                  Namespace Interface
 
pwd                  Print working directory
 
quit                Exit from EOS console
 
quota                Quota System configuration
 
reconnect            Forces a re-authentication of the shell
 
recycle              Recycle Bin Functionality
 
rmdir                Remove a directory
 
rm                  Remove a file
 
role                Set the client role
 
rtlog                Get realtime log output from mgm & fst servers
 
silent              Toggle silent flag for stdout
 
space                Space configuration
 
stat                Run 'stat' on a file or directory
 
test                Run performance test
 
timing              Toggle timing flag for execution time measurement
 
transfer            Transfer Interface
 
version              Verbose client/server version
 
vid                  Virtual ID System Configuration
 
vst                  Virtual Storage Interface
 
whoami              Determine how we are mapped on server side
 
who                  Statistics about connected users
 
?                    Synonym for `help'
 
.q                  Exit from EOS console
 
 
</nowiki>
 
 
=== Misc ===
 
* [https://twiki.cern.ch/twiki/bin/view/AtlasComputing/ATLASStorageAtCERN ATLAS Storage at CERN] (main link)
 
* [https://indico.cern.ch/event/119650/contribution/4/material/slides/1.pdf ATLAS Migration of disk pools] from CASTOR to EOS
 
* [https://twiki.cern.ch/twiki/bin/view/AtlasComputing/TierZeroExpertOnCallNotes ATLAS documentation - Tier-0 expert on call notes]
 
* [https://en.wikipedia.org/wiki/ATLAS_experiment General description of ATLAS - some basic data rates references]
 
* Some Older but informative links
 
** [https://twiki.cern.ch/twiki/pub/Main/DaqTierZeroTierOnePlanning/ALICE__DAQ-T0-T1_architecture_and_time_schedules.doc ALICE DAQ Architecture Document]
 
** [https://twiki.cern.ch/twiki/pub/Main/DaqTierZeroTierOnePlanning/CDRandT0scenarios3.doc LHC-wide document analyzing data recording]
 
 
== Data Management ==
 
* [https://dcameron.web.cern.ch/dcameron/docs/chep07-atlas-ddm.pdf ATLAS DDM (CHEP07)]
 
* [http://iopscience.iop.org/1742-6596/219/6/062037/pdf/1742-6596_219_6_062037.pdf ATLAS DDM (CHEP10)]
 

Latest revision as of 17:36, 30 November 2017

ARCHIVAL






Select Documents and Meetings

Appendix I

An early example of the measurements program

Particle Type Momentum Range (GeV/c) Bin (MeV/c)
p 0.1-2.0 100
p 2.0-10.0 200
π± 0.1-2.0 100
π± 2.0-10.0 200
μ± 0.1-1.0 50
μ± 1.0-10.0 200
e± 0.1-2.0 100
e± 2.0-10.0 200
K+ 0.1-1.0 100
γ(π0) 0.1-2.0 100
γ(π0) 2.0-5.0 200

Appendix II

The detector characterization includes a few distinct areas, and the goals of measurements in each affect the desired statistics. A few items are presented below.

Energy Scale and Resolution

In terms of detector characterization, some of the important parameters include energy scale and resolution for both single tracks and showers - hadronic and EM. Let's consider them first (using comments from T.Junk):

  • Energy scale: for Gaussian distribution, uncertainty will be sigma/sqrt(n). Assuming resolution of 1%, and aiming for ±0.1% precision, only 100 events would be needed.
  • Hadronic showers: older calorimeters had resolution of 80%/sqrt(E). Since sampling fraction in LAr TPC is higher, we are likely to do better than this, but still conservatively assume O(10%)/sqrt. Qualitatively, we can follow arguments similar to the previous item. It follows then that O(103-104) events will be enough for the purposes of this measurement. Indeed, looking at typical test beam and calibration practices (per papers published), we see that 104 events is the typical statistics for a given incident beam momentum.

In summary, depending on case, this part of the measurement program can be accomplished with event sample of the size ~O(103-104), and in some cases less.

PID

Measuring the "fake" rate, i.e. particle mis-identification, is important for certain physics to be addressed by the experiment (cf. proton decay). If the probability of mis-PID is "p", then the statistical uncertainty can be expressed as sqrt(p*(1-p)/n). This can also be understood in terms of precise measurements of "tails" in certain distributions. If we are looking at probabilities of mis-identification of the order of 10-6, this translates into quite substantial statistics. At the time of writing, we need more guidance in this area, but in general it appears that in this case we would indeed be motivated to take as much data as practically feasible. This does mean that we will aim to take a few million events in each of a few momentum bins (TBD). Reading: Nucleon Decay Searches

Systematics

Let's assume we want to measure a signal with 5% precision and signal to background ratio is 1:10. To provide this scale of accuracy, we will need ~105 events in the momentum bin of interest.