Upgrade and development for calorimetry
for Deeply
Virtual Compton Scattering
VI. Nuclear Physics (NP)
Alexandre Camsonne
Early Career Internal Review
Executive Summary/Abstract
•
•
•
The structure of the nucleon is one of the main research axis at
Jefferson Laboratory.
General Parton Distributions (GPDs) are a generalization of the
concept of Form Factor and parton distributions which are
defined as limit of General Parton Distributions. The GPDs give
an additional spatial dimension to our knowledge of the parton
in the nucleon and could solve the spin crisis once measured.
The Hall A experiment was able to measure of absolute cross
section for DVCS using a calorimeter associated with Flash
ADCs this is the most direct measurement to access GPDs.
The experience from the previous experiments showed that the
background in the calorimeter was a limiting factor for
resolution and luminosity. Improvement in calorimetry radiation
and background hardnessness is crucial for the 12 GeV
program.
Early Career Internal Review
Specific Scientific Aims
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•
Continue the Lead Fluoride PbF2 effort for 12 GeV Hall A
experiment
Upgrade electronics to reduce effect of background on resolution
•
Investigate possibility of use of gaseous detector as replacement of
PMT to eliminate PMT aging issue due to background.
•
Investigate sampling calorimeter using Micro Pattern Gaseous
detector by making a small prototype. By design this kind of detector
is less sensitive to low energy background but energy resolution at
Jlab range should be determined an optimized.
Build full size calorimeter and evaluate performance in beam and
compare to PbF2 during Hall A DVCS experiment.
Early Career Internal Review
Research Impact and Benefits
Impact and benefits for Jefferson Lab
Improved quality of and efficiency of data taking, for any
experiment using calorimetry at 12 GeV and beyond by providing
radiation hardness, low downtime and an increased in luminosity
treatment of background for improved resolution in high
background conditions. This will open the way to studies of low
counting rate channels such as Double DVCS or J/psi production
Impact and benefits for Nuclear Physics
High radiation hardness calorimetry will be useful for many other
experiment requiring calorimetry in hostile environment such as
EIC and other high energy facilities.
Impact and benefits for Office of Science
Gaseous photodector can also be a cheaper alternative to PMTs
which could be used in medical application.
Early Career Internal Review
Resources Needed
Funding : Manpower 125 K$ a year
Procurement : 375 K$ a year
PI 50% of work charge (35 K$ year )
Additional man power to complete the project :
1 Jlab Designer for calorimeter redesign for 2 years
1 postdoc hired 100 % on grant ( 50 K$ year )
1 PHd student funded by grant (25 K$), 2 PhD student by
collaborating Universities
Collaborators : CEA Saclay , Old Dominion University 1 professor,
Ohio University 1 professor, IPN Orsay 1 staff scientist
Ressources :
Machine shop, detector group, electronic group, test lab, clean
room
Early Career Internal Review
Schedule and Milestones
M : Milestone
R : result
Q1
Electronics upgrade
50 K$
Procurement PbF2
100K$
2012
Q2 Q3
Q4
Q1
2013
Q2 Q3
Q4
Q1
Q4
Q1
100K
$
100K
12.5
K$
Redesign of calorimeter
PbF2 Calorimeter complete
20 K$
Test run with visible Micromegas with PbF2
50 K$
Procure sampling calorimeter prototype lead
50 K$
Procure sampling calorimeter prototype electronics
Prototype building/testing
Prototype Test complete
Procure MGPD for sampling calorimeter
50 K$
Procure sampling calorimeter lead
50 K$
2015
Q2 Q3
Q4
Q1
2016
Q2 Q3
Q4
50K$ M
200K
$
Block selection irradiation tests
M
12.5
K$
M
M
R
M
R
Procure sampling calorimeter electronics
Sampling Calorimeter design
Sampling Calorimeter frame
2014
Q2 Q3
50 K$
25K$
25K$
50K$
65
K$
50K$
200
65K$
65K$
125K
$
125K
$
65K$
M
50K$ M
Procure PMTs or build gaseous photon detector
Hall A DVCS experiment install
Hall A DVCS experiment data taking
Hall A DVCS complete
M
R
Early Career Internal Review