1 / 17

Alexandre Camsonne Jefferson Laboratory Hall A Collaboration meeting June 21 st 2007

Complete Separation of Deeply Virtual Photon and p 0 Electroproduction Observables on Unpolarized Protons E07-007. Alexandre Camsonne Jefferson Laboratory Hall A Collaboration meeting June 21 st 2007. Overview. New DVCS experiment What we learnt from E00-110 and E03-106 DVCS 2

austin-baldwin
Download Presentation

Alexandre Camsonne Jefferson Laboratory Hall A Collaboration meeting June 21 st 2007

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Complete Separation of Deeply Virtual Photon and p0Electroproduction Observables on Unpolarized ProtonsE07-007 Alexandre Camsonne Jefferson Laboratory Hall A Collaboration meeting June 21st 2007

  2. Overview • New DVCS experiment • What we learnt from E00-110 and E03-106 • DVCS2 • p0 production • Detector upgrade • Calorimeter • Radiation hardness test • Calorimeter upgrade • Electronics upgrade • Sampling system upgrade • Calorimeter trigger upgrade • Man power • Timeline • Conclusion Hall A Collaboration meeting November 19, 2014

  3. E00-110 and E03-106 • First dedicated experiment proposed for the study of the Deeply Virtual Compton Scattering ( E00-110 ) • 4 years of developments, ran in 2004 • A unique approach from what was done previously and now • High resolution on a limited kinematic range • Study of scaling with fixed xbj and variation in Q2 • High resolution calorimeter • Focus on cross section measurement • Ensure exclusivity • High luminosity 1037 cm-2.s-1 Hall A Collaboration meeting November 19, 2014

  4. Experimental setup Hall A Collaboration meeting November 19, 2014

  5. What we learnt from E00-110 and E03-106 • The good • Experiment is possible • New dedicated electronics worked ( elastic cross section ) • Resolution is sufficient to work in double arm • The “less” good • Triple coincidence cross sections are difficult ( on going effort to understand efficiency of proton array ) • Radiation damage very random • Calibration of the calorimeter is very important because of radiation damages • p0 were cut by threshold on calorimeter trigger • Dead time can be large with high spectrometer rates • Better study of background effects needed to be taken into account in simulation ( more random runs ) Hall A Collaboration meeting November 19, 2014

  6. What we learnt about physics • Early scaling • Contribution of the DVCS2 amplitude is not negligible at JLab kinematics • p0 production very interesting to study • Calibration is possible using p0 and p- Hall A Collaboration meeting November 19, 2014

  7. E07-007 motivations • Improvements compared to previous experiment • Use of 2 beam energies • Study p0 production with a LT separation • Study of the importance of the DVCS2 • Calorimeter work • Increase size for larger acceptance • Blocks selection • Curing of radiation damage • Improvement in p0 detection • Better kinematical range ( lower threshold cut) • Improved p0 subtraction Hall A Collaboration meeting November 19, 2014

  8. For the future experiments 3.6 - 3.7 % E07-007 motivations Expected errors : • At this day (Jun 21 2007): • 3% HRS+PbF2 acceptance +luminosity + target • 3% H(e,e’g)Xg p0 background • 2% Inclusive H(e,e’g)Np 2% Radiative Corrections only on the cross section difference • 2% Beam polarization measurement 2%X 1% X 1%X Total (quadratic sum)= 5.1% (5.6%) Hall A Collaboration meeting November 19, 2014

  9. New experimental setup • Double arm experiment : proton array not needed • Calorimeter • Increased size of the calorimeter from 132 to 208 blocks for larger acceptance in t • Electronics • Improved trigger for optimal pi0 detection • Speed improvement to accommodate lower threshold Hall A Collaboration meeting November 19, 2014

  10. Experimental setup New beamline design Hall A Collaboration meeting November 19, 2014

  11. E07-007 new issues • No proton array means higher luminosity but also higher irradiation damages • p0 detection imply lower thresholds • New trigger scheme • Improve rate capability of system Hall A Collaboration meeting November 19, 2014

  12. Calorimeter curing • Systematic irradiation of blocks to reject the bad ones • Ohio State University • Test transmission summer student Sylvain Gregoire • FEL block irradiation test: recreate dose from experiment • Blue light curing process similar to process used at Mainz on PVA4 Hall A Collaboration meeting November 19, 2014

  13. Data acquisition • Redesign for new calorimeter geometry • New trigger • Triggering on total sum • Digital • Analog sum • Multiple level trigger Effectively reduce threshold on many clusters event to detect p0 Hall A Collaboration meeting November 19, 2014

  14. Data acquisition • Sampling system • Different alternative • Simple one increase bandwidth by using larger number of crates • Upgrade ARS motherboard to new technologies using same form factor • VME64 ( 80 Mbytes/s ) • 2eVME ( 160 Mbytes/s ) • VME320SST ( 320 Mbytes/s) • Switch serial VXS ( 1 Gbyte/s) • Technical choice to be decided soon since we have 2 years to develop • Depends on man power available Hall A Collaboration meeting November 19, 2014

  15. Man power • Ohio • Clermont Ferrand • ODU • Jefferson Laboratory • More collaborators welcomed ! • Calorimeter design • Mechanical design • electronics • Analysis • Collaboration meeting in September Hall A Collaboration meeting November 19, 2014

  16. Timeline • MRI submitted for financing calorimeter upgrade by ODU/OU • Result by the end of June • Procurement of PMTs and PbF2 blocks • Electronics • FEL irradiation tests • Fall 2007 • Start fiscal year 2008 : mechanical design • might be scheduled as soon as second half of 2009 Hall A Collaboration meeting November 19, 2014

  17. Conclusion • Capitalizing on what was learnt from the previous experiments by improving the method • LT separation for the p0 • Evaluation of the importance of the DVCS amplitude • 6 GeV experiment in could run in 2009 • Research and development on PbF2 calorimeter curing • Development of new trigger scheme and investigating electronics speed improvement. Hall A Collaboration meeting November 19, 2014

More Related