Search for Solar Axions: CAST Biljana Lakić IRB Zagreb, TU Darmstadt for the CAST collaboration 2004 LHC DAYS IN SPLIT, 5 – 9 October 2004 LHC DAYS IN

Search for Solar Axions: CASTSearch for Solar Axions: CASTSearch for Solar Axions: CASTSearch for Solar Axions: CAST

Biljana LakiBiljana LakiććIRB Zagreb, TU DarmstadtIRB Zagreb, TU Darmstadt

for the CAST collaborationfor the CAST collaboration

2004 LHC DAYS IN SPLIT, 5 – 9 October 2004 LHC DAYS IN SPLIT, 5 – 9 October

Biljana LakiBiljana Lakićć 2004 LHC DAYS IN SPLIT 2004 LHC DAYS IN SPLIT

Outline:Outline:

AxionsAxions The CAST experiment:The CAST experiment:

Physics behind the experimentPhysics behind the experiment Description:Description:

Magnet, trackingMagnet, tracking X-ray telescope and X-ray detectorsX-ray telescope and X-ray detectors

Analysis and preliminary resultsAnalysis and preliminary results ProspectsProspects


AxionsAxions

The strong CP problem:The strong CP problem:

a

μνa GG

~

8s

CP strong L MdetArg(QCD vacuum + EW quark mixing)(QCD vacuum + EW quark mixing)

Peccei-Quinn solution:Peccei-Quinn solution:

-new global chiral U(1)-new global chiral U(1)PQPQ symmetry spontaneously broken at scale f symmetry spontaneously broken at scale faa

-associated pseudo Nambu-Goldstone boson: -associated pseudo Nambu-Goldstone boson: axion !axion !

aμνa

aa GGa

faa

~

82

1 sL

aa f

mGeV10

eV66

-axion mass:-axion mass:Axion: pseudoscalar, neutral, Axion: pseudoscalar, neutral,

practically stablepractically stable

-direct contribution to the electric dipole moment of the neutron direct contribution to the electric dipole moment of the neutron ddnn

-strong experimental bound on strong experimental bound on ddnn requires requires

910

absorbed in the definition of absorbed in the definition of a a


AxionsAxions

Axion models:Axion models: Standard axion model (fStandard axion model (faaffweakweak) excluded experimentaly) excluded experimentaly

Invisible axion models (fInvisible axion models (faa>>f>>fweakweak, g, g1/f1/faa, , mmaa~1/f~1/faa)) KSVZ KSVZ (Kim, Shifman, Vainshtein, Zakharov)(Kim, Shifman, Vainshtein, Zakharov) DFSZ (Dine, Fischler, Srednicki, Zhitnitskii)DFSZ (Dine, Fischler, Srednicki, Zhitnitskii)

-axion-photon coupling via triangle loop-axion-photon coupling via triangle loop

-axion-pion mixing-axion-pion mixing

Axion-photon coupling:Axion-photon coupling:

08.092.1213

42

2 N

E

fwz

wz

N

E

fg

aaa


CAST: PhysicsCAST: Physics

aγaa

aγ dEtSP

dE

dΦN

a thermal photon converts a thermal photon converts into an axion in the Coulomb into an axion in the Coulomb fields of nuclei and fields of nuclei and electrons in the solar plasma electrons in the solar plasma ((Primakoff processPrimakoff process))

an axion converts into a an axion converts into a photon in a strong transverse photon in a strong transverse magnetic fieldmagnetic field

Sun:Sun:

Earth:Earth:

-expected number of photons-expected number of photons

S = detector effective areaS = detector effective area

t = measurement timet = measurement time



112keV1.08/E

3a

2

110

aγγ10

a

a keVscm1e

/keVE

GeV10

g104.02

dE

dΦa

2

GeV10

g110

aγγ

keV4.2Ea

- differential axion flux at the Earth:- differential axion flux at the Earth:

K. van Bibber K. van Bibber et alet al.,1989.,1989



qLcose2e14/Γq

1

2

BgP 2L/ΓLΓ

22

2

aγγγa

a

2a

2γ

E2

mmq

L

πE2mm

L

πE2mπqL a2

γaa2

γ

-conversion probability in the -conversion probability in the gas (in vacuum: gas (in vacuum: = 0, m= 0, m=0):=0):

L=magnet length, L=magnet length, =absorption coeff.=absorption coeff.

T(K)

P(mbar) 0.02(eV)mγ

axion-photon momentum transfer axion-photon momentum transfer

effective photon mass effective photon mass (T=1.8 K)(T=1.8 K)

-coherence condition:-coherence condition:


CAST: PhysicsCAST: Physics Predicted exclusion plotPredicted exclusion plot

• 1 year with vacuum in the 1 year with vacuum in the magnet bores: magnet bores: m < 2.3m < 2.31010-2 -2

eV eV (during 2003 and 2004)(during 2003 and 2004)

• 1 year with 1 year with 44He gas pressure He gas pressure increased from 0 - 6 mbar in increased from 0 - 6 mbar in 100 increments: 100 increments: m < 0.26 eVm < 0.26 eV

•1 year with 1 year with 33He gas pressure He gas pressure increased from 6 - 60 mbar in increased from 6 - 60 mbar in 365 increments : 365 increments : m < 0.83 eVm < 0.83 eV

To start in 2005 To start in 2005


CAST: CollaborationCAST: Collaboration

Canada, Vancouver, Bc, University of British ColumbiaDepartment of Physics (1 participant(s)) Team Leader: Michael HASINOFFMichael HASINOFF Croatia, ZagrebRuder Boskovic Institute (3 participant(s)) Team Leader: Milica KRCMARMilica KRCMAR, Biljana LAKIC, Ante LJUBICIC France, Gif-Sur-Yvette, Centre d'Etudes de Saclay (CEA-Saclay)DAPNIA (6 participant(s)) Team Leader: Ioanis GIOMATARISSamuel ANDRIAMONJE, Alain DELBART, Esther FERRER RIBAS, Ioanis GIOMATARIS, Emile PASQUETTO, Jean Pierre ROBERT Germany, Darmstadt, Technische Universitat DarmstadtInstitut für Kernphysik (6 participant(s)) Team Leader: Konstantin ZIOUTASHorst BALONIER, Theopisti DAFNI, Dieter HOFFMANN, Joachim JACOBY, Manfred MUTTERER, Hans RIEGE Germany, Frankfurt Am Main, Johann-Wolfgang-Goethe Universität FrankfurtInstitut für Kernphysik Team Leader: Konstantin ZIOUTASGermany, FreiburgAlbert-Ludwigs-Universität Freiburg (6 participant(s)) Team Leader: Kay KONIGSMANNHorst FISCHER, Jurgen FRANZ, Igor GARCIA IRASTORZA, Fritz-Herbert HEINSIUS, Donghwa KANG, Kay KONIGSMANN Germany, Garching, Max-Planck-Gesellschaft (MPG)Max-Planck-Institut für Extraterrestrische Physik (2 participant(s)) Team Leader: Markus KUSTERHeinrich BRAEUNINGER, Markus KUSTER Germany, MuenchenMax-Planck-Institut fόr Physik (3 participant(s)) Team Leader: Gerhard LUTZRainer KOTTHAUS, Gerhard LUTZ, Georg RAFFELT Greece, AthensNational Center for Scientific Research "Demokritos" (NRCPS) (4 participant(s)) Team Leader: George FANOURAKISGeorge FANOURAKIS, Theodoros GERALIS, Konstantinos KOUSOURIS, Aikaterini ZACHARIADOU

Greece, ThessalonikiAristotle University of Thessaloníki (6 participant(s)) Team Leader: Christos ELEFTHERIADISSpyridon DEDOUSIS, Christos ELEFTHERIADIS, Anastasios LIOLIOS, Argyrios NIKOLAIDIS, Ilias SAVVIDIS, Konstantin ZIOUTASItaly, Pisa Scuola Normale Superiore (SNS) (1 participant(s)) Team Leader: Luigi DI LELLALuigi DI LELLA Russia, Moskva, Russian Academy of SciencesInstitute for Nuclear Research (INR) (3 participant(s)) Team Leader: Sergei GNINENKOAlexandre BELOV, Sergei GNINENKO, Nikolai GOLUBEV Spain, Zaragoza, Universidad de Zaragoza Facultad de CienciasInstituto de Física Nuclear y Altas Energías (7 participant(s)) Team Leader: Angel MORALESBerta BELTRAN LIZARRAGA, Jose CARMONA MARTINEZ, Gloria LUZON MARCO, Julio MORALES, Jaime RUZ ARMENDARIZ, Maria SARSA, Jose VILLAR Switzerland, GeneveEuropean Organization for Nuclear Research (CERN) (12 participant(s)) Team Leader: Martyn DAVENPORTKlaus BARTH, Gino CIPOLLA, Martyn DAVENPORT, Rui DE OLIVEIRA, Fabio FORMENTI, Jean-Noel JOUX, Christian LASSEUR, Angelika LIPPITSCH, Thomas PAPAEVANGELOU, Alfredo PLACCI, Bruno VULLIERME, Louis WALCKIERS United States of America, Chicago Il, University of ChicagoEnrico Fermi Institute (3 participant(s)) Team Leader: Juan COLLARJuan COLLAR, David MILLER, Joaquin VIEIRA United States of America, Columbia Sc, University of South CarolinaDepartment of Physics and Astronomy (2 participant(s)) Team Leader: Frank AVIGNONERichard CRESWICK, Horacio FARACH

The total number of participants: 65


CAST: CERN Axion Solar TelescopeCAST: CERN Axion Solar Telescope

Decomissioned LCH test magnet

Rotating platform

3 X-ray detectors

X-ray Focusing Device

Decomissioned LCH test magnet

Rotating platform

3 X-ray detectors

X-ray Focusing Device


CAST: Magnet, trackingCAST: Magnet, tracking L= 9.26 m

B=9 T

100 times better than any other !!

CAST Experimental area SR8


CAST: Magnet, trackingCAST: Magnet, tracking

•Motors•Encoders•E. Readout computer•Software with astronomical calculations•Interface to move magnet•New angle encoders

Calibrated and correlated with celestial coordinates Calibrated and correlated with celestial coordinates high precision geometer measurements (precision 0.01high precision geometer measurements (precision 0.01))

Snapshot of the Snapshot of the tracking programtracking program


CAST: Magnet, trackingCAST: Magnet, tracking

March 2003March 2003

September 2003September 2003

Twice a year (September and March) Twice a year (September and March) we can film the Sun through the we can film the Sun through the

windowwindow


CAST: Telescope, detectorsCAST: Telescope, detectors

X-Ray Telescope (Focusing Device)

Detectors

CCD

Micromegas

TPC


CAST: X-ray telescopeCAST: X-ray telescope

27 concentrically nested mirror shells:

- focal length 1.6 m

- diameter 164 mm

Space technology:Space technology:

prototype for the satellite ABRIXAS prototype for the satellite ABRIXAS

X-ray telescope with the CCD in placeX-ray telescope with the CCD in place


CAST: X-ray telescopeCAST: X-ray telescope

from 43 mm (LHC magnet aperture) to ~3 mm ∅ ∅

signal-to-noise improvement (up to 200!!!)

43 mm 43 mm

1.6 m1.6 m

3 mm 3 mm

~35% efficiency due to reflections


CAST: CCDCAST: CCD

Geometry: 200Geometry: 20064 pixels (164 pixels (13 3 cmcm22))

Pixel size: 150Pixel size: 150150 150 mm22

CCD temperature: -130CCD temperature: -130 C C

excellent space resolutionexcellent space resolution

pn-CCD chippn-CCD chip cooling maskcooling maskShield: low activity Shield: low activity copper and lead copper and lead


CAST: CCDCAST: CCD

Efficiency (1-7 keV): > 95 % Efficiency (1-7 keV): > 95 % constrained only by telescopeconstrained only by telescope

FWHM: 160 eV @ 6 keV FWHM: 160 eV @ 6 keV excellent energy resolutionexcellent energy resolution

55Fe 5.9 keV lines K,L

Background spectrumBackground spectrum

~ 10~ 10-4-4 counts keV counts keV-1-1 s s-1 -1 cmcm-2-2

(Cu and Au lines from the (Cu and Au lines from the cooling mask)cooling mask)


CAST: MicromegasCAST: Micromegas

192 charge collection strips for x192 charge collection strips for x

192 charge collection strips for y192 charge collection strips for yMicromegas in placeMicromegas in place

Gas: Ar 95%, Isobutane 5%Gas: Ar 95%, Isobutane 5%

CAST prototypeCAST prototype


CAST: MicromegasCAST: Micromegas

Background rate:Background rate:

1010-4-4-10-10-5 -5 counts scounts s-1 -1 cmcm-2-2 keV keV-1 -1

20032003

20042004

5.9 keV X-ray Spectrum


CAST: TPCCAST: TPC

Geometry: 30 cm Geometry: 30 cm 15 cm 15 cm 10 10 cmcm

Gas: Ar 95%, CHGas: Ar 95%, CH44 5% 5%

Position sensitive (3 mm spacing)Position sensitive (3 mm spacing)

48 anode wires (x)48 anode wires (x)

96 cathode wires (y)96 cathode wires (y)


CAST: TPCCAST: TPC

Integrated spectrum from 1-10 keV:

9.3×10-5 cts/keV/s/cm2

3.8×10-5 cts/keV/s/cm2

There is an improvement by a

factor of 2.4!!E (keV)E (keV)

55Fe Calibration spectrum

Clean materials + shielding (polyethylene + copper + ancient lead)


CAST: Analysis 2003CAST: Analysis 2003 CCDCCD

TPCTPC

MicromegasMicromegas

-no signal observed so far-no signal observed so far


CAST: Analysis 2003CAST: Analysis 2003

ggaa (95% C.L.) < 1.2(95% C.L.) < 1.21010-10-10 GeV GeV-1-1

Combined upper Combined upper limit limit (preliminary !)(preliminary !)


CAST: ProspectsCAST: Prospects

• Vacuum in the magnet bores: Vacuum in the magnet bores: 2003 & 20042003 & 2004

• PHASE 2: PHASE 2: 44He & He & 33He in the magnet bores He in the magnet bores to start in to start in 2005 !2005 !

……. and also …. and also …

• High energy axions: High energy calorimeter installed during High energy axions: High energy calorimeter installed during 20042004

• Axion astronomy Axion astronomy

• 14.4 keV solar nuclear axion line14.4 keV solar nuclear axion line

• Kaluza-Klein axionsKaluza-Klein axions

Documents

Search for Solar Axions: CAST Biljana Lakić IRB Zagreb, TU Darmstadt for the CAST collaboration 2004 LHC DAYS IN SPLIT, 5 – 9 October 2004 LHC DAYS IN