LHCb VELO Upgrade

The upgraded LHCb VELO silicon vertex detector is a lightweight hybrid pixel detector capable of 40 MHz readout at a luminosity of 2 x 1033 cm-2 s-1. The track reconstruction speed and precision is enhanced relative to the current VELO detector even at the high occupancy conditions of the upgrade, due to the pixel geometry and a closest distance of approach to the LHC beams of just 5.1 mm for the first sensitive pixel. Cooling is provided by evaporative CO2 circulating microchannel cooling substrates. The detector contains 41 million 55 μm × 55 μm pixels, read out by the custom developed VeloPix front end ASIC. The detector will start operation together with the rest of the upgraded LHCb experiment after the LHC LS2 shutdown, currently scheduled to end in 2019. The VELO upgrade has been described in the Technical Design Report , submitted in November 2013 which lays out the planned construction and installation, and gives an overview of the expected detector performance. Some key figures and diagrams related to the VELO Upgrade can be found on our collection at Material for Presentations. Â

The Velo Upgrade Project operates under the responsibility of the VELO Project leader Paula Collins and deputy project leader Kazu Akiba Some practical links are given in the table below. The project is organised into workpackages which are given in the list below.

Mechanics Girish Patel RF Foil Modules Database  Infrastructure Software Mark Williams,Tomasz Szumlak Reconstruction Software VP Nomenclature      Electronics Jan Buytaert         DAQ Integration Karol Hennessy DAQ Main Module Production DAQ Upgrade DAQ logbook    ASIC Martin Van Beuzekom ASIC twiki workpage VeloPix Design Meetings      Module Stefano de Capua and Daniel Hynds. Module twiki workpage (old) module meetings      Sensors Gianluigi Casse Testbeam Database  Simulations Bump bonding Publications Material for Presentations Conference Talks Notes and Publications Theses Reviews, EDRs

The VELO Upgrade work packages:

 

Upgrade Software

• Mark Williams, Tomasz Szumlak
• Velo simulation and reconstruction software

Electronics

• Jan Buytaert Workpackage webpage here

DAQ Integration

• Karol Hennessy Workpackage webpage here

VELOPIX ASIC 

• VELO Pixel ASIC coordinator Martin Van Beuzekom, Workpackage webpage here

Module

• Stefano de Capua and Eddy Jans. Workpackage webpage here
• Pixelmodulezero meetings are held weekly and can be consulted here .

Module Cooling 

• Malcolm John, Workpackage webpage here
• Velo Upgrade cooling meetings are held weekly at 10 am Monday CET and can be searched in indico under "Velo Upgrade Cooling". In addition the "LHCb CO2 Cooling meetings" discuss the general status of the joint cooling plant development for the UT and Velo Upgrade.

Mechanics 

• Girish Patel, here
• The responsibility for this workpackage after the retirement of Girish Patel is taken over by Kurt Rinnert and Themis Bowcock pending the appointment of the new workpackage coordinator, expected for Q2 2016

RF boxes

• Wouter Hulsbergen, here

Sensor activity

The VELO upgrade baseline option is for planar sensors, approximately 200 um thick. In the past, 3d and diamond sensors have been considered.  

• Planar Sensor coordinator: Gianluigi Casse, Workpackage webpage here

Testbeam

The VELO upgrade testbeam programme is very active, coordinated by Kazu Akiba and Martin van Beuzekom

Please find the twiki page here

 

Upgrade commissioning

VeloUpgradeCommissioning

Microchannel Cooled Hybrid Pixels for LHCb

The decision to replace the Phase I VELO Strip detector with pixels was adopted in 2013 at a dedicated technology review held at Nikhef, Amsterdam. Some workpackages were dedicated to the concept development and R&D for this review, and have now been completed. This includes the workpackage setting in place the Strawman Defintion workpackage and the investigations of alternative pixel sensor technologies incuding 3D (Presentation by Chris Parkes on 3D detectors ) and diamond sensors which were not in the end adopted for the Upgrade. Considerable work was put into the development of a strip option, which is described at the technology review links given above. The initial descriptions of the development of hybrid pixel modules, based on the electronics chip "VeloPix" derived from Timepix2, as a baseline option was described in our LOI  and developed in the Framework TDR . The VELO Institutes committed to involvement in various aspects of the VELO Upgrade activities by completing a survey velo_expression_of_interest_4.xlsx and some technical information about the simulation studies can be found here.The old R&D pages can be found here.

 

Other Interesting Links and Reference Documents

LHCb Upgrade Expression of Interest 

Timepix/Medipix

 

• Xavi LLopart Timepix Design: PhD Thesis 
• Jan Jakubek Timepix Calibration - IWORID 2009 
• Jan Jakubek et. al Pixel Detectors for Imaging with Heavy Charged Particles 
• Jan Jakubek et al Precise Energy Calibration of Pixel Detector working in Time-Over-Threshold Mode
• Lukas Tlustos Medipix2 and Timepix CERN PH-ESE Seminar 
• Medipix2_testbeam.pdf: Muon imaging with medipix
• Medipix3DTestbeamJSR_v2.pdf: Medipix testbeam at Diamond facility
• timepix_nim_coor.pdf: Time Pix NIM publication, general description
• timep-x_nim.pdf: Timepix NIM paper, general description II
• LHCb_front-end.docx: Document describing a study of modifications of the Medipix for LHCb RICH

 

Material for presentations

* Material for Presentations

Documents currently in preparation

 

• Timepix Testbeam 2009 results 
• VELO Contribution to LHCb Upgrade LOI 
• Document describing requirements for upgraded VELO detector (veloupgradepaper.pdf) 
• Document describing Timepix proposal (testpaper.pdf) 
• poster_pixel2010.ppt: Richard Plackett - LHCb VELO Upgrade Pixel 2010 
• poster_VELOpgrade_twepp09_2.ppt: Jan Buytaert - LHCb VELO upgrade TWEPP 2009 
• poster_VELOpgrade_twepp09_2.ppt: Jan Buytaert - TWEPP 2009 poster 
• poster_VELOpgrade_twepp09_2.ppt: Jan Buytaert - TWEPP 2009 poster 
• nobu.pdf: p-spray and p-stop rad hard silicon design 
• oct_7_2010_thesis_tuomas_poikela_FINAL.pdf: Tuomas Poikela Master Thesis on VeloPix architecture 
• poster_pixel2012_pc.pdf: pixel 2012 gdm poster 
• SALT_DSP.pdf: Current Digital Processing Chain for the SALT chip 
• VeloLogo.gif:

• Plan of activities in the pit:
  

• P8Activities.mpp: Plan of activities in the pit (Microsoft project source file)