Transcript Search for Neutrinoless double beta-decays with the Enriched Xenon Observatory Derek Mackay and Nicole Ackerman.

Search for Neutrinoless double beta-decays with the
Enriched Xenon Observatory
Derek Mackay and Nicole Ackerman
What are we doing here?
Moving the Clean Rooms (x 6)!
The Xe vessel
Vacuum
insulation
HFE (Heat
transfer fluid)
25cm enclosure
of low activity
lead
EXO TPC Detector
Inside Xenon Vessel
EXO’s Crown Jewels
Largest enriched isotope stockpile in the world
unrelated to the Nuclear Weapon/Energy Industry
Russian Enrichment Facility
Part of EXO Funding rationalization was
to keep enrichment Facilities Occupied
with non-Nuclear Weapon Activities
Next Generation EXO- Barium Tagging
LHe cryostat
Actuator
SXe-coated
tip
Can potentially completely
eliminate background events
LXe cell
Quadrupole Trap for Ba Ions
U
CCD
Scope
Vcos(Ωt) + U
Spectroscopy
lasers
DC potential [V]
0 Volts
-5 Volts
Identifying the Barium
2P
1/2
650nm
493nm
4D
2S
1/2
metastable 47s
3/2
EXO-200 Sensitivity (Current Experiment)
Case
Mass Eff.
(ton)
(%)
Run
Time
(yr)
EXO-200
0.2
70
2
σE/E @ Radioactive
2.5MeV Background
(%)
(events)
1.6*
40
T1/20ν
Majorana mass
(yr,
90%CL)
(meV)
6.4*1025
QRPA1 NSM2
133
186
Next Generation EXO Sensitivity
Case
Mass
Eff.
(ton)
(%)
Run
Time
(yr)
σE/E @
2νββ
2.5MeV Background
(%)
(events)
T1/20ν
Majorana mass
(yr,
90%CL)
(meV)
QRPA1 NSM2
Conserva
tive
1
70
5
1.6*
1
2*1027
24
33
Aggressi
ve
10
70
10
1†
1
4.1*1028
5.3
7.3
EXO Schedule
Current Status: All Clean Rooms are underground
and are in the process of being reassembled.
•
• March 2008: Complete a full cool down test of the
system (full test except for the actual detector – a test
chamber will be used instead)
• August 2008: Complete cool down test with actual
detector with natural “cheap” Xenon.
•Fall 2008: Start Data run with enriched Xenon