ICHEP 2006 1 / 24 Status Report of CERN Axion Solar Telescope (CAST) Experiment Dieter H.H. Hoffmann...
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Transcript of ICHEP 2006 1 / 24 Status Report of CERN Axion Solar Telescope (CAST) Experiment Dieter H.H. Hoffmann...
ICHEP 2006 1 / 24
Status Report of Status Report of CERN Axion Solar Telescope (CAST) CERN Axion Solar Telescope (CAST)
ExperimentExperiment
Dieter H.H. Hoffmann(Tech. University Darmstadt & GSI – Darmstadt)
on behalf of the CAST collaboration
ICHEP, Moscow July 27ICHEP, Moscow July 27thth 2006 2006
ICHEP 2006 2 / 24
Summary of presentation
• Brief CAST overview • Analysis of 2004 data (phase I)• CAST phase II• Schedule for next months• Conclusions
CAST Collaboration
ICHEP 2006 3 / 24
CERN and CAST
CAST
ICHEP 2006 4 / 24
CAST working principle Sikivie [1983]
Axion source Axion detection
ICHEP 2006 5 / 24
CAST historyCAST history
2002 2003 2004 2005 2006
CAST construction
CAST phase I CAST phase II
First commissioning runs
First Physics runs
Physics runs – Enhanced operation
Work to upgrade for phase II
First physics runs – phase II 4He
Phase II (4He) operation
ICHEP 2006 6 / 24
Cern Axion Solar Telescope
Thomas Sahner
ICHEP 2006 7 / 24
CAST setup overviewCAST setup overview
LHC test magnet
TPC
Micromegas&
CCD/Telescope
ICHEP 2006 8 / 24
ICHEP 2006 9 / 24
Tracking System:
Calibrated and correlated with celestial coordinates
Tracking System:
Calibrated and correlated with celestial coordinates
Twice a year (September&March) we can
film the Sun through the window
Twice a year (September&March) we can
film the Sun through the window
Looking at sunrise
Magnet, sun tracking
ICHEP 2006 10 / 24
TPC
ICHEP 2006 11 / 24
HECμM
XRTCCD
HEC
ICHEP 2006 12 / 24
keV4.2Ea
Solar axion spectrum
Paγ 1.710-17
2
GeV10
g110
aγγ
ICHEP 2006 13 / 24
ICHEP 2006 14 / 24
ICHEP 2006 15 / 24
~33% →
On-Axis Effective Areas at PANTER and at CAST
0.0
2.0
4.0
6.0
8.0
10.0
12.0
0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5
Energy [keV]
Calculated effective area in PANTER (48 mm diameter aperture)
Measured Effective area in PANTER (48 mm diameter aperture)
Expected effective area at CAST (42 mm diameter aperture)
The effective area of the X-ray telescope f (Eγ).
↓ 4.5 keV
ICHEP 2006 16 / 24
ICHEP 2006 17 / 24
2004 data analysis2004 data analysisCCD/Telescope
• Spot position well determined• Full sensitivity of telescope
exploited• Counts inside the spot
compatible with background level
Tracking data Signal simulation
•No axion signal detected
ICHEP 2006 18 / 24
2004 data analysis2004 data analysis
TPC 2004 subtracted spectrum Micromegas 2004 subtracted spectrum
• ~200 h of tracking data for each detector• Almost non-interrupted operation. High quality data
•No axion signal detected
ICHEP 2006 19 / 24
2004 result2004 result
for
• New exclusion plot, improving 2003 result
• Factor of 7 improvement beyond previous experimental searches.
• It goes beyond astrophysical limit of globular clusters for coherence masses
• Publication now under preparation
ICHEP 2006 20 / 24
CAST phase II – principle of CAST phase II – principle of detectiondetection
Extending the coherence to higher axion masses...•Coherence condition (qL << 1) is recovered for a narrow mass range around m
Ne: number of electrons/cm3
: gas density (g/cm3)
axionsTransverse magnetic field (B)
X ray
X raydetector
L
Aaxions
Transverse magnetic field (B)Transverse magnetic field (B)X ray
X raydetector
X ray
X raydetector
X ray
X raydetector
L
A
ICHEP 2006 21 / 24
CAST phase IICAST phase II
• CAST phase II approved CAST phase II approved by CERN Research Board by CERN Research Board on Dec 2004on Dec 2004• Data taking with Data taking with 44He He started last Novemberstarted last November• 33He phase will start mid He phase will start mid 2007 (LLNL will provide 2007 (LLNL will provide the the 33He)He)
CAST phase II sensitivityCAST phase II sensitivity
Cosmological limit Cosmological limit (Hannestad et al, JCAP 0507 (05) 002)(Hannestad et al, JCAP 0507 (05) 002)
Presentprogress
ICHEP 2006 22 / 24
ScheduleSchedule
2006 July Aug Sep Oct Nov Dec
Data taking with 4He • 1 step per day
• tests for ramping?
3He system road map
Complete TDR
Complete Add. MoU
TD Review Start construction components
New detection line MM+optic
PANTER tests
Installation in CAST
P ~ 9 mbarP ~ 9 mbarmmaa ~ 0.31eV ~ 0.31eV
PP ~ 12 mbar~ 12 mbar
mmaa ~ 0.37eV~ 0.37eV
ICHEP 2006 23 / 24
ScheduleSchedule
2007 J F M A M J J A S O N D
3He System
Installation in CAST
Commissioning
Data taking
• Start 3He
physics runs• Double step• Possibility of ramping mode?
2008 2009
Data taking • Time needed to fully exploit new setup
P ~ 45 mbarP ~ 45 mbarmmaa ~ 0.71 eV ~ 0.71 eV
P ~ 120 mbarP ~ 120 mbarmmaa ~ 1.16 eV ~ 1.16 eV
ICHEP 2006 24 / 24
ConclusionsConclusions• CAST has successfully performed its transition into
phase II:• Phase I data analysis finished. Publication under preparation• Upgrades to start phase II done during 2005: 4He system, cold
windows• Phase II 4He data taking ongoing
• Started in Nov 2005• Up to 4 mbar scanned already. 4He runs planned until the end of
the year• Installation of new detector line with a second X-ray
optics planned before the end of the year• Phase II 3He operation scheduled for mid next year
• 3He system designed. Technical report in preparation• Schedule for next months has been presented• CAST will reach 60 mbar (0.8 eV) during 2008• 3He allows extension to even higher masses (1.16 eV)