Download - Silicon Drift Detectors for the kaonic atom X-ray measurements in the SIDDHARTA experiment
1/20
Silicon Drift Detectors for the kaonic atom X-ray
measurements in the SIDDHARTA experiment
T. Ishiwatari Stefan Meyer Institut, Vienna, Austria
SIDDHARTA CollaborationSilicon Drift Detector for Hadronic Atom Research by Timing Applications
LNF- INFN, Frascati, ItalyStefan Meyer Institut, Vienna, Austria
Politecnico, Milano, ItalyMPE, Garching, Germany
PNSensors, Munich, GermanyIFIN – HH, Bucharest, Romania
Univ. Victoria, CanadaRIKEN, Japan The 11th VCI 2007 Feb 19-24,2007
2/20
Silicon Drift Detectors for the kaonic atom X-ray measurements in the SIDDHARTA experiment
1. Kaonic atom X-rays
2. Kaonic hydrogen with CCDs
(DEAR, LNF)
3. Silicon Drift Detectors
4. Kaonic helium with SDDs
(E570,KEK)
5. Kaonic hydrogen & deuterium with SDDs
by Monte Carlo
(SIDDHARTA, LNF)
3/20
)(
22
2311
FormulaDeser
ai ss
)(
22
2311
FormulaDeser
ai ss
Shift () and width () of K-p and K-d gives isospin dependent KN scattering lengths(a0 and a1)
These scattering lengths provide Low-energy SU(3) QCD:SU(3) chiral symmetry, KN -term, nature of (1405), S0 ( 3115 ) S + (3140)
Difficulty1. High-background
in kaon beams
2.Small X-ray yields
(a few% K-p, below 1% K-d)
3.Precise determination of
X-ray energy and width
X-ray detector with 1. high background rejection,
2. large-area,
3. good resolution in energy and time
Kaonic atom X-rays and KN scattering lengths
4/20
Katom Old exp.
1H Attractive shift
2D No data
3He No data
4He Large shift
New exp.
Repulsive shift
No data
No data
Small shift
repulsive attractive
-500 5000
wid
th
1s
[eV
]
0
200
400
600
800
1000
shift 1s [eV]
Dav
ies
Izyc
ki e
t al,
1980
Bird
198
3
Results of kaonic hydrogen
Accuracy for K-p,First for K-d(as well as 4He,3He)are badly needed!
Experimental results of kaonic atoms
KpX
DEAR
Iwas
aki e
t al,
1997
Phys. Rev. Lett. 94, 212302 (2005)
5/20
DEAR
DAFNE e+e- collider optimized to produce -meson at rest (1.020 GeV)
KKee KKee
K- beam at DAFNE1. Monochromatic2. Low-energy3. No hadronic background
K- beam at DAFNE1. Monochromatic2. Low-energy3. No hadronic background
/day103~
/day2~
,3000~
6
1
K
pbdtL
nbKK
DEAR experiment at DAFNE
6/20
DEAR experimental setup
TMP
CCD Electronics
Vacuum Chamber
APD Cryo-Cooler
CryoTigerCCD Cooling
CCD Pre-Amplifier
CCD55-Chips
Kaon MonitorKaon Monitor
16 CCD55-30 (EEV) -1242 x 1152 pixels - pixel size 22.5 x 22.5 m- total area 7.24 cm2 per chip- depletion depth ~30 m- read-out time 1 min.- energy resolution ~150 eV @ 6keV- temperature at 165 K
16 CCD55-30 (EEV) -1242 x 1152 pixels - pixel size 22.5 x 22.5 m- total area 7.24 cm2 per chip- depletion depth ~30 m- read-out time 1 min.- energy resolution ~150 eV @ 6keV- temperature at 165 K
7/20
X-ray events 1 and 2 pixel eventsCharged particles large pixel eventsbackground suppression by pixel analysis
CCD X-ray detector
8/20
S/N~1:70
PRL 94, 212302 (2005)
1s = - 193 ± 37 (stat.) ± 6 (syst.) eV1s = 249 ± 111 (stat.) ± 30 (syst.) eV
1s = - 193 ± 37 (stat.) ± 6 (syst.) eV1s = 249 ± 111 (stat.) ± 30 (syst.) eV
DEAR results
K-p energy spectrum by DEAR CCDs
X-ray events
NIMA 556(2006)509
X-rays : 1,2 pixelsMIPs :~ 8 pixels,Some MIPs: ~ 1,2 pixelsbackground events on X-ray spectraTiming needed!
Part
s of
MIP
s ~1,
2 pi
xels
9/20
SDD (Silicon Drift Detector) X-ray detector
Low capacitance
SDDSi(Li)
electrode type
anodecathode
small anode large-area, high energy resolution,Thin depletion reduce background caused by electron/gamma
Q = CV = (ε0S / d ) V
Q = CV = (ε0S / d ) V
10/20
Si(Li) SDD
Detector Si(Li) CCD SDD
Area [mm2] 200 724 100
Thickness [mm] 5 0.03 0.30
E (FWHM)
[eV] 410 170 185
t (FWHM) [ns] 290 - 430
Comparison of X-ray detectors used for kaonic X-ray experiments
These values are obtained during the beam times.
11/20
Kaonic Helium X-rays with SDDs (E570, KEK)
KETEK 1 cm2 SDD
E570
Energy resolution ~185 eV @ 6 keV
Effective Area 1cm2 * 8 SDDs
Thickness 0.26 mm
Temperature ~85 K
Energy calibrationIn-beam
(Ti and Ni)
Fiducial volume cut Yes
K-4He La X-rays
12/20
1) 8 Silicon Drift Detectors “SDDs”1) 8 Silicon Drift Detectors “SDDs”
K-
X-ray
Charged particles
LHe target
3) Reconstruction of K and charged particles
3) Reconstruction of K and charged particles
Drift chamber (PDC,VDC)
BDC
E570 experimental setup
13/20
2 4 6 8 10
Energy [keV]
1
10
10
10
10
105
4
3
2
1
Cou
nts/
30 e
V
Self trigger
Events from target cell
104 times less
Ti K
KHe 3-2
Ni Ka
KHe 4-2
KHe 5-2
Kaonic 4He Energy spectra with SDDs
14/20
SIDDHARTA experiment (LNF, Italy)
New SDDs specially designed for SIDDHARTA
200 SDDs with 1cm2 per SDDon-chip preamp
New SDDs specially designed for SIDDHARTA
200 SDDs with 1cm2 per SDDon-chip preamp
Silicon Drift Detectors for Hadronic Atom Research
by Timing Application
15/20
Triple coincidence: SDDX * ScintK * ScintK
Scintillator
Scintillator
Target
SD
De+
e-
S/N =1:70 (CCD)10:1 (SDD)for kaonic Hydrogen
K+
Φ K+ + K-
K-
Triple coincidence technique
X-ray
16/20
Temperature 22 KPressure max. 5 bar
Kaon entrance Window:Kapton 150 m
Side wall:Kapton 75 µm
200 SDDs with 1cm2 per SDD
17/20
SDDs electronics
Cryogenic target cell
Kaon entrance window
18/20
Energy (keV)
Background suppression >103
MIPs (e+/e-) in SDD
Kaon decays
Signal rate ~ 2.2x10-3 /s130 /d (duty cycle=2/3 of d.)
Monte Carlo for SIDDHARTA
W/o coincidence
With coincidence ofK+, K-, X-ray
19/20
Energy (keV)
Kaonic hydrogen
Kaonic deutrium
K Kβ
Kg, ...
K-p: ε1s = 193 eV, Γ1s = 249 eV, Y(Kα )=2%precision: ε1s ± 3 eV Γ1s ± 5 eV
K-d: ε1s = 325 eV, Γ1s = 630 eV, Y(Kα )=0.2%precision: ε1s ± 18 eV Γ1s ± 45 eV
Energy spectra in SIDDHARTA (Monte Carlo)
Signal rate ~ 2.2x10-3 /s130 /d (duty cycle=2/3 of d.) 30 days data taking
S/N=10:1
S/N=1:1
20/20
Summary•Application of SDD X-ray detectors in the field
of kaonic atoms is given.•SDDs have good Energy resolution as well as good Time resolution.•Prototype of Large-area SDDs are tested with a kaon beam at
KEK successfully.•High performance on Energy resolution, Time resolution, Background rejection capability was measured.•We are now developing new type of Large-area SDDs specially designed for SIDDHARATA experiment.•SIDDHATA will obtain
the most accurate for kaonic hydrogen X-rays, and the first observation of kaonic deuterium X-rays.
•The physics runs start from 2007.
Part of the work was supported by "Transnational Access to Research Infrastructure" (TARI),HadronPhysics I3, Contract No. RII3-CT-2004-506078.
21/20
Silicon Drift Detector
GND
UBACK
UIRUOR
high energy resolution at fast shaping times, due to the small anode capacitance
Q = CV = (S / d ) V
Q = CV = (S / d ) V
Small capacitance
SDDSi(Li)
electrode type
anodecathode
22/20
1) 8 Silicon Drift Detectors “SDDs”1) 8 Silicon Drift Detectors “SDDs”
K-
2) Ti and Ni foils2) Ti and Ni foils
X-ray
Charged particles
LHe target
-(or K-)
3) Reconstruction of K and charged particles
3) Reconstruction of K and charged particles
Ti,Ni X-rays
Drift chamber
Scint
E570 experimental setup