Reports
Laser system overview.pdf , bailleux 2009
Lasers in used :
- Diode pump laser DP2, x2, 447nm (1mJ/pulse)
- Ti:S laser pumped by YLF laser, 800 nm (1.48mJ/pulse)
- Diode laser DTL-419QT, 527nm (200 uJ/pulse)
Main specifications of the system with the DP2-2:
Kejun_nss12_laser_2.pdf ; Calor_Liyuan ; DP brochure photonics
The 76,000 lead tungstate (PbWO4) crystals
in the CMS electromagnetic calorimeter (ECAL) are radiation hard to high
integrated dose, but suffer from dose rate dependent radiation damage. The light
Higgs discovery potential is directly related to the energy resolution of the
ECAL at LHC, and thus requires precision calibration. The
ability to calibrate the crystal calorimeter precisely will be a major factor in
determining its ultimate performance. The following 3 aspects are considered:
precalibration in a test beam, in situ calibration using physics
events and a precise and stable light monitoring system (laser).
2 lasers: one for the crystals (
447nm) and one for electronic (800 nm). Laser should have enough power to generate light equivalent to
several hundred GeV in a few hundreds crystal at time. The light will be
transported to the crystals via optical fibers and through 3 levels of
distribution. The light from each pulse will be normalized using Si PN
photodiodes at each of the levels of distribution.
Laser for crystals:
inject light pulses into each individual PbWO4 crystal to measure the optical
transmission near the scintillation spectrum peak (~500nm), and occasionally,
as a cross check (700nm).
The red laser 800nm is used time to time
to study the wavelength dependency of the transparency corrections.
3 levels of distribution:
a light source and high-level distribution system which sends pulses to a
selected calorimeter element (1/2 barrel supermodule or endcap), and a 2-level
distribution
system mounted on each calorimeter which delivers the pulses to the
crystals.
The system is designed to continuously monitor the calorimeter in one of the
2 operational modes:
- Continuous in-fill mode (during 3 us gaps every 88,924 u sin the LHC beam),
- Stand-alone monitoring (outside LHC fills to follow the recovery of the PbWO4
crystals)
To meet the stringent requirements on the light
monitoring precision and stability a new commercial diode-pumped blue laser
("DP2-447") has been commissioned and installed at CERN for the 2012
operation of the CMS ECAL (TiS laser before) The laser unit has a simple structure and is
expected to be more reliable than the existing lamp-pumped lasers used by
the monitoring system. The stability of critical quantities such as the
intensity, width and timing, is better than that of the lamp-pumped lasers.
2019
CMS LSO safety new barrack CMS_LSO_LS2.pptx
ETN from Photonics Q19-0815CX - 11-381 DP2-ETN.pdf
OM meeting Laser maintenance August Laser maintenance_August2019.pptx
ECALdays B.Lenzi Monitoring Upgrade BL_LMupgrade_ECalDays_2019_05_22.pdf
ECAL days Laser correction UltraLegacyTags_ECALdays_Zurich.pdf
Dave Cockerill EE power - Laser scan laser-power-vs-pn-data.pdf
Long fibre Test - report Long fiber test_2.pptx
2018
integration forum, 15 Jan laser_room_15Jan2018.pdf
long fibre test Long fiber test_20March.pptx
USC barrack integration USC_CO2_Cooling_Room_Ph2 Copy.pdf USC_Control_room_Ph2.pdf
Laser presentation for HCAL Laser for HCAL meeting 082018.pptx
2016
DPG Amina, end of year 161212_AZ_ECALDPGWorkshop.pdf
Status after Liyuan intervention 29March: Laser status TC Avril 2016.pptx
ECAL DPG March: MarcD_DPG_160329.pdf intercalibration laser/VFE , temp effect from laser room..
2015
ECAL review 2-3Feb Marc_ecalReviewFeb2015.pdf ; P_Gras_ecalReviewFeb2015.pdf
Calibration Workshop October calibration_Amina_oct2015.pdf
laser status Oct LasersOct2015.pptx
2014
OM 26 Nov pgras-20141124.pdf ; JLF_OM_26112014_R.pdf
MoCA 24 Nov MD_MoCa_141120.pdf
laser status cms week Oct Laser status Oct 2014.pdf
OM 16april DP2_commision_GR.pdf
MoCA August (new monitorning box) MD_Moca_140828.pdf
WGM meeting 9 April (CMS wedn) CMS_wedn_meeting_WGM.pdf
OM meeting March, trigger effect on amplitude: https://indico.cern.ch/event/306670/
Report before 2nd DP2 installation (DPG March) DP2_12-658_summary.pdf
OM meeting January: https://indico.cern.ch/event/298179/
2013
laser_system_summary_3.pdf Renyuan, December
ECAL_GRIN.pdf, Nov.
DP2_12-658_output_power_10-11-2013.pdf 2nd DP2 at Caltech
after RH installation at Photonics.
Update on the DP2-447s_Oct-11-2013.pdf
report/reports2013/Update on the DP2-447s_Sept-23.pdf
Update on DP2-447_Caltech_July2013.pdf
laser_system_summary_1_April.pdf, Renyuan CMS week
diode_pump_laser, Kejun, ECAL conference committee , end 2012
Laser setup with the 2 Photonics .pdf
power measurement 18Fev2013.pptx
2012
cms week Adi Dec2012_Adi.pdf
OM Meeting 19Sept: ZHU_OM_19Sept2012.pdf; liyuan_OM_19Sept.pdf; PowerDP2_OM_19Sept.pdf
nss12_dp2_summary-1.pdf Kejun, IEEE-NSS-MIC-RTDS2012 USA
OM_meeting_11July2012.pdf OM meeting 11 July power measurement 11July.pdf
Liyuan_CMS_week_June.pdf https://indico.cern.ch/conferenceDisplay.py?confId=197823
OM_meeting_20June2012.pdf OM meeting 20 June
power measurement 11 June.pdf OM meeting 13 June
Incident history report.pptx 2012 list of incidents
Easter Incident Caltech group meeting.pptx (wrong date, not easter but 1 May) https://indico.cern.ch/conferenceDisplay.py?confId=168368
Power measurement , OM meeting 2 May
22 March monitoring meeting:
Kejun_DP2-447_Measurement_Caltech_March2012.pdf
Liyuan_DP2-447_Measurement_Caltech_March2012.pdf
Philippe_Control of new lasers.pdf
ZHU_CMS_Feb2012_without_Photonics_schematics.pdf
Marc_ECAL_FEb2012.pdf New laser DP optical path, planning to do 2012.
2011
https://cms-docdb.cern.ch/cgi-bin/DocDB/ShowDocument?docid=5662
Summary laser choice.pptx Dave B.
laser1_11Oct2011.pdf Laser1 problem 6-11 Oct (end of tuning 11 Oct)
wolfram_110929_Laser.pdf Ecal days
ZHU_CaltehMeeting.pdf Caltech meeting https://indico.cern.ch/conferenceDisplay.py?confId=119886
Lasers_27Sept2011.pdf Caltech and OM meeting. Matacq plots over 96hrs
laser status 20July.pdf OM meeting
ecal_federico_matacq.pdf CMS week
laser status 8JUNE.pdf OM meeting
laser status 1JUNE.pdf OM meeting
Summary_Meeting_1_ECAL_Laser_TF.docx
2010
ryz_101207_laser_replacement.pdf
Federico_Ferri_Calor May 2010.pdf
2009
LaserSystem review_15 Oct.pptx Calibration and monitoring review
Laser summary_3 August 09.docx
Laser Electronic Review 2009.pptx Werner, electronics review part1 (doc)
Laser MO_March2009.pptx US CMS meeting, CMS week
YLF laser upgrade.pdf Diode PUMP
Laser tasks_CMS week March09.doc CMS week (for Werner)
2008
B-field_onlaser_1.pdf * modify presentation to a report version
LASER under CMS field Nov.pdf *Ecal pt5 commissioning meeting Nov
ECALDays_Laser_Monitoring_July2008_Adi.pdf
2007
Kejun_071029_N09-4_mon.pdf Laser generale + feedback
TB_2007-03-22_JV_PulseWidth_v2.pdf (J.Veverka)
monitor2 Saclay, CMS internal note
Adi Data processing May2007.pdf
2006
nss06_laser_tns1.pdf (IEEE NSS at San Diego)
nss06_laser_1.pdf (Software feedback control)
Laser feedback Test Beam meeting 19July2006
2005
CMS_Conference_report 23Feb2005 (IEEE)
04_tns_monitor.pdf, IEEE Trans. Nucl. Sci.Vol. 52 No. 4 (2005) 1123--1130 (August 2005)
F http://agenda.cern.ch/fullAgenda.php?ida=a055740
LaserWorshop_David_16092005.pdf
LaserWorkshop_Adi_16092005[1].pdf
2004
David, Test beam _ 01 Sept 04.pdf, or web page
CleanRoom_project.ppt, 28/Nov/04 (Alain Herve, Patrick Ingenito, Andrea Gaddi)
Ryz_041028_usc55.pdf,28/Nov/04 (Alain Herve, Patrick Ingenito, Andrea Gaddi)
2003
Monitor_ins_2003.pdf (Installation Note, CMS IN 2003-045)