Status Report to the SPSC at CERN

For the CAST collaboration:

Dieter H.H. HoffmannGSI Darmstadt and

TU-Darmstadt

CERN, 13.05.03

The CAST Experiment

(1) Croatia, ZagrebRuder Boskovic InstituteÊ

Milica KRCMAR, Ante LJUBICIC, B. LAKIC

Ê(2) France, Gif-Sur-YvetteCentre d'Etudes de Saclay (CEA-Saclay), DAPNIAÊAlain DELBART, Ioanis GIOMATARIS, SamuelANDRIAMONJE

Ê(3) Germany, DarmstadtTechnische Universitat Darmstadt, Institut f�r KernphysikÊTheopisti DAFNI , Dieter HOFFMANN, Manfred MUTTERER,Thomas PAPAEVANGELOU, Hans RIEGE,Yannis SEMERTZIDIS

Ê(4) Germany, FrankfurtApplied Physics

Vladimir ARSOV, Joachim JACOBYÊ

(5) Germany, FreiburgAlbert-Ludwigs-Universit�t FreiburgÊHorst FISCHER, Juergen FRANZ , Fritz Hertbert HEINSIUS,Donghwa KANG, Kay K�NIGSMANN

(6) Germany, GarchingMax-Planck-Gesellschaft (MPG), Max-Planck-Institut f�rExtraterrestrische PhysikÊHeinrich BRAUNINGER, Jakob ENGLHAUSER

(7) Germany, MuenchenMax-Planck-Institut f�r Physik, Werner-Heisenberg-InstitutÊRainer KOTTHAUS, Markus KUSTER, Gerhard LUTZ, GeorgRAFFELT

(8) Greece, AthensNational Center for Scientific Research "Demokritos"(NRCPS)ÊGeorge FANOURAKIS, Theodoros GERALIS, KaterinaZACHARIADOU

Ê

(9) Geece, ThessalonikiAristotle University of Thessalon�kiÊSpyridon DEDOUSSIS, Christos ELEFTHERIADIS,Anastasios LIOLIOS, Argyrios NIKOLAIDIS, IliasSAVVIDIS, Vlasios VASILEIOU, Konstantin ZIOUTAS

(10) Italy, PisaScuola Normale Superiore (SNS)Luigi DiLella

(11) Russia, MoskvaRussian Academy of Sciences, Institute for NuclearResearch (INR)ÊSergei GNINENKO, Nikolai GOLOUBEV

(12) Spain, ZaragozaUniversidad de Zaragoza, Facultad de Ciencias,Instituto de F�sica Nuclear y Altas Energ�asÊJose CARMONA, Susana CEBRIAN, Gloria LUZON,Angel MORALES, Julio MORALES, Alfonso ORTIZ DESOLORZANO, Marisa SARSA, Jose VILLAR

Ê(13) Switzerland, GeneveEuropean Organization for Nuclear Research (CERN)ÊKlaus BARTH, Martyn DAVENPORT, Rui DE OLIVEIRA,Fabio FORMENTI, Michael HASINOFF1, IgorIRASTORZA, Alfredo PLACCI, Laura STEWART, BrunoVULLIERME, Louis WALCKIERS

(14) United States of America, Chicago, IlUniversity of Chicago, Enrico Fermi InstituteÊJuan COLLAR

(15) United States of America, Columbia, ScUniversity of South Carolina, Department of Physicsand AstronomyÊFrank AVIGNONE, Richard CRESWICK, HoracioFARACH

Ê

The CAST Collaboration

-Axions

-CAST : Status

-Magnet, power supply, cryogenics, sun

tracking

-Detectors:

TPCMicromegasX-ray Telescope and CCD

-Outlook

Outline:

Solaraxions

axions

Transve

rse m

agne

tic fie

ld (B)

X ray

X ray

detector

AXION PHOTON CONVERSION

L

COHERENCE 1

Principle of detection

Solar Axions

Flux

PRIMAKOFF EFFECT

[K.van Bibber et al.,1989]

Axions

Sunset

Photon detectors Sunrise

Photon detectors

Sunset axions

Sunrise axions

Decomissioned LHC test magnet

Rotating platform

3 X-ray detectors

X-ray Focusing Device

Decomissioned LHC test magnet

Rotating platform

3 X-ray detectors

X-ray Focusing Device

Cern Axion Solar Telescope

L= 10 m, B=9 T

à100 times betterthan previous exp.

CAST

Tracking System:

Calibrated and correlated withcelestial coordinates

Tracking System:

Calibrated and correlated withcelestial 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 atsunrise

Magnet,platform,cryogenics

Tracking the Sun

Magnet Power Supply

Magnet Quenching

Detectors

Micromegas

Double polypropylene (C3H6) window

Zone CTubeP = 10-6 mbar

Zone BIn-between chamberP = 10-4 mbar

Zone ADetectorP= 1 bar (Ar)

Window 1:with strongback 4 µm poly.+ 0.3 µm Al

Window 2: 4 µm poly.

P1 P2Microvalve 1

Valve 2

A B C

Gate valve

CERN pumping unitnew pumping unit

Valve 3

Microvalve 4(vent)

MicromegasHelium leak rate: 3á10-9 mbar l/s

Software efficiency 78.5% à 3.7 10-5 /sá cm2 ákeV

55Fe

Background 2002

Background under different conditions

Low Background:

<10-5 counts keV-1cm-2s-1

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

55Fe Calibration spectrumTPC

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 2 4 6 8 10

E (keV)

Effic

ienc

y

Overall efficiency@ axion spectrum 70%

TPC efficiency

PanterFacility MPE

Background runs with magnet current OFF

Background runs with magnet current ON

Solar data runs (magnet ON & tracking)

L M X J V S D L M X J V S D

Sep

16 17 18 19 20 21 22 23 24 25 26 27 28 29

Oct

Sep

30 1 2 3 4 5 6 7 8 9 10 11 12 13

Oct 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Nov

Oct 28 29 30 31 1 2 3 4 5 6 7 8 9 10

Nov 11 12 13 14 15 16 17 18 19 20 21 22 23 24

First tracking run 25min

Hakidiki meeting

13th CAST meeting

Dec

Nov 25 26 27 28 29 30 1 2 3 4 5 6 7 8

Dec 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Jan

Dec 23 24 25 26 27 28 29 30 31 1 2 3 4 5

Jan

6 7 8 9 10 11 12 13 14 15 16 17 18 19

Feb

Jan

20 21 22 23 24 25 26 27 28 29 30 31 1 214th CAST meeting

SC monitoring

Hourly calibrations

Perio

d #1

(oct

-nov

Ô02)

Perio

d #2

(dec

Õ02 Ð

janÕ

03)

Set #1.9

Summary of TPC data (up to JanÕ03)

Background data

5 NOV

18 NOV14 NOV 23 NOV

SET 9 to be analyzed

Run 2002

Preliminary Axion Exclusion Plot

c/cm

2 /s/b

in

Energy (ADC channels)

Using only data set #9:- 4.7 hours of Sun tracking data- 58 hours of background withreasonable stability

g ~ 1.5 x 10-10 GeV-1

(-3.0 ± 5.0(2σ)) _ 10-5 c/cm2/sec[1-8 keV]

-11

-10

-9

-8

-7

-4 -3 -2 -1 0 1

log[ma / eV]

log[gα

γγ / G

eV-1]

SOLAX + COSME

TOKYO HELIOSCOPE

CAST 2002

CAST PROSPECTS

CAST Sensitivity

Preliminary Axion Exclusion PlotComparison CAST-Tokyo sensitivities

Solar axion spectrum for g~ 6 x 10-10 GeV-1

(Tokyo Helioscopesensitivity)

CAST TPC4.7 h spectrum(bck subtracted)

E27 nested pairs of mirrors

EFrom 43 mm ∆ (LHC magnet aperture) to ~1mm ∆

signal and background simultaneously

signal-to-noise improvement

1.7 m

50mm _

1mm _

~35% efficiency dueto reflections

The X-Ray Telescope

x-y image of 6.4 KeV X-raybeam in MicroMegas chamber

(log scale for density)

Test @MPE -Panter facility

Telescope on the Magnet

with the CCD in place

Space technology:

Spare part of the ABRIXASSpace mission

X-Ray telescope alignment

Cu shield

Cu-K

Background,03.04.2003,14 hrs

EBackground:

~10-4 events keV-1 s-1cm-2

EEfficiency closeto 100% over thefull energy range:

Windowless

CCD

Threshold = 0.2 keV Prev. exp. > 3 keV

CCD Background

LHC / AT-VAC group

¥Requirements for the mirror contamination

¥Residual gas analysis by J.P.Bojon

Vacuum Conditions at CAST

10-7 g/cm2 ~2.5 . 10-9 moles/cm2~ 1.5 1015 molecules/cm2

~1 monolayer (ML)

We are approximatelyspeaking of 1 ML ofheavy molecules

We want a coverage less than 1 monolayer to beattained during 3 years vacuum operation

Contamination of the Mirror

Magnet beam pipe vacuum

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

0.1 1 10 100 1000 10000

Pumping time (hours)

Pre

ssu

re (

mb

ar)

2% CxHx (300 K)

0.06% CxHx (4 K)

...last minute .....

Micromegas

Micromegas

Tracking (~16 hours )

Background (~91 hours )

keV

C/k

eV/s

/cm

2

TPC

Conclusions

CAST : Status

Magnet Cryogenics Power Supply Sun tracking

Detectors:

TPC Micromegas

CCD

X-ray telescope

üÊ

üÊ

üÊ

üÊ

üÊ

üÊ

üÊ

üÊ

( )

May 1st 2003 àààà data taking

Improvements

Other (non)solar physics

14th June

H.E. Axions

Kaluza-Klein Axions@2nd phase of CAST

-11

-10

-9

-8

-7

-4 -3 -2 -1 0 1

log[ma / eV]

log[gα

γγ / G

eV-1]

SOLAX + COSME

TOKYO HELIOSCOPE

CAST 2002

CAST PROSPECTS

CAST Sensitivity

End

-12

-11

-10

-9

-8

-7

-4 -3 -2 -1 0 1

log[ma / eV]

log[ gα

γγ / G

eV-1 ]

SOLAX + COSME

TOKYO HELIOSCOPE

CAST 2002

CAST PROSPECTS (QCD axions)

(KK axions n=2 δ=2)

(KK axions n=2 δ=1)

Preliminary Axion Exclusion Plot

Already goes beyondTokyo result

g ~ 2 x 10-10 GeV-1 (~2σ limit)

Preliminary!¥Integral rate used only (more statistical refinements using spectral information could give betterresult)¥Conservative cuts¥No efficiency correction (small change)

Background dataEvolution of background with time

during October-November

¥Events after cuts¥Rate in fixed ADC range (roughly 3-7 keV)far from threshold and saturation limits

àààà Physical background (no noise)

Igor G. Irastorza 13th CAST Meeting - CERN 23.11.2002

8 OCT

15 OCT 22 OCT 25 OCT

X-ray focusing device (MPI)

üPrinciple

üTechnology for space X-ray telescopesüRecycled for CAST

Igor G. Irastorza, CERN / Zaragoza U. IDM 2002, York, UK, September 2002

CAST Vacuum scheme

Procedure

A baseline BLANK spectrum is obtained with valve closedbefore any analysis

Valve is opened and a spectrum taken

magnet 1.8K

cryostat's insulation vacuum

bellows

RGAResidual Gas

Analyzer