LARGE AREA TRANSITION-EDGE SENSOR ARRAY FOR PARTICLE INDUCED X-RAY

EMISSION SPECTROSCOPY

M Palosaari1, K Kinnunen1, I Maasilta1, C Reintsema2, D Schmidt2, J Fowler2, R Doriese2, J Ullom2, M Käyhkö1, J Julin1, Mikko Laitinen1, T Sajavaara1

1Department of Physics, University of Jyväskylä, P.O. Box 35, Jyväskylä 40014, Finland2National Institute of Standards and Technology, Boulder CO 80305, United States

email: mikko.i.laitinen@jyu.fi

INTRODUCTION to TESSuperconducting Transition-Edge Sensor

Transition-Edge Sensor (TES)

TES as a calorimeter– Measures the energy of incident radiation

Schematics of a calorimeter

Typical pulse from a calorimeter

TES Operation Operates between superconducting and normal state

Extremely sensitive R(T)

Excellent energy resolution

Wide energy range

Detects radiation,in our case X-rays

Particles also possible

Typical transition of a TES

Normal state

Superconducting state

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sitio

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ge

TES basics TES thin film device is made of normal metal -

superconducting metal bilayer.

The absorber details depend on the desired energy range.

TESs are usually fabricated on thin SiN membranes to limit the thermal conductivity G.

Photograph of a 256 pixelTES array made in VTT, Finland.

In typical TES array, all pixels different-> automated calibration essential

PIXE-TES SETUP IN JYVÄSKYLÄ

PIXE-TES Setup in Jyväskylä

~300 m~15 mm

Details inside the instrument

Jyväskylä TES specifications 160 pixels from NIST, upgradable to 256 (from VTT)

Total area with 160 pixels ~16 mm2

Single pixel count rate limited to <20 Hz, typical value 10 Hz

2 m thick Bi absorber with Mo/Cu superconducting juction

Detection efficiencieswith 100 um of Be:80 % at 5 keV,20 % at 10 keV, 5 % at 30 keV

Low energies limited byMeV particle absorber,probably not needed

PIXE-TES MEASUREMENTSFrom a single pixel to many…

PIXE-TES results from Jyväskylä

Mn Kα from Fe-55 sourceBest pixel

Instrumental resolution for the best pixel with 55Fe source was 3.06 eV

Roughly one year ago: 12 pixels

PIXE-TES results from Jyväskylä

• But, Computer interface and I/O cards cannot handle all pixels simultaneously

• I/O card + PC update coming from NIST to finally secure the function of all 256 possible channels, simultaneously.

This month: data with Fe-55 source

Resolution around 5 eVfor combined 40 pixels,Improvement seen bybetter dataanalysis

Now: 160 pixels…

PIXE-TES results from Jyväskylä

SRM-611, trace elements in glass

All TES data shown was analyzed last week, 1 eV / bin

Analysis resolution for all of these plots ~10 eV

PIXE-TES results from Jyväskylä

SRM-611, trace elements in glass

PIXE-TES results from Jyväskylä

SRM-611, trace elements in glass

Differences between pixels which are not only statistics

PIXE-TES results from Jyväskylä

SRM-1157, speciality tool steel

No Si escape peak

Bi escape peaks

Single measurement, wide energy range

PIXE-TES results from Jyväskylä

SRM-1157, speciality tool steel

V, Cr, Mn, Fe separated

Read-out upgraded to full scale.

Modification of PIXE setup to be able to measure samples in atmosphere.

Study art samples in a project that just started

X-ray measurements with our own detector array fabricated by VTT.

Study the satellite peaks with different ions and energies. ->> Chemical information from wide energy/elemental range ???

In the Near Future

Conclusions Instrumental resolution of 3 eV demonstrated

Combined pixel resolution of ~5 eV looks realistic

Wide energy scale (“0” to tens of keV)

Reasonable count rates available (10 Hz/pixel, 256 pixels)

Active detector area about 16 mm2

No liquid He needed for ADR cryo cooler

Largish instrument: ~5 cm sample-to-detector

Data handling and analysis: automation necessary

Is the chemical information achievable, after all ?

Acknowledgements

t

3-8. July, 2016, in Jyväskylä, Finland

Pixel calibrationSingle pixel shows Si peaks nicely but without good calibration, sum spectrum useless

good calibration

No/bad calibration regime

Sample: SRM-611

TES-PIXE data calibrationRaw pulse height data

where sample was changed.

Measurement time/duration

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ale

Substrate was Si for both samples

Sample 1 Sample 2

TES-PIXE dataMaking selection to single (example) emission line

•Before liner fit

Straight line to guide the eye

TES-PIXE data

Si

SiStraight line to guide the eye

• After linear fit

Nitride hits

Mn Kα from Fe55 sourcesame pixel

PIXE Mn vs. 55Fe

What is the origin of the hump?

Detector performance: PIXE Mn vs. 55Fe source

Instrumental resolution for the best pixel with 55Fe source was 3.06 eV.

For 2 MeV protons and Mn sample resolution was 4.20 eV.

M. Palosaari et. al J. Low Temp.DOI 201310.1007/s10909-013-1004-5

PIXE applications

Traditional PIXE applications– Archaeology– Geology– Filters in industry– Old paintings

Rev. Sci. Instrum. 78, 073105 (2007) J. Hasegawa et. al

With better detectorsone could see thechemical environmentof the sample.

TES vs. SDD

Impurities in the Cu sample resolved better with TES detector

Stainless steel example

Mn Kα from Fe55 sourcesame pixel

FWHM broadens less than 1eV.

PIXE Mn vs. 55Fe

TES vs. SDD

TES circuit diagram

Example: Thin film with high mass element Atomic layer deposited Ru film on HF cleaned Si

Scattered beam, 35Cl, used for Ru deph profile

Monte Carlo simulations needed for getting reliable values for light impurities at the middle of the film

Ru

Si

SiO2

Low energy heavy ion ERDA – See posters!

Poor E resolution

Example: Diamond-like carbon films 2.3 µm thick diamond-like-carbon film on Si, measured with 9 MeV 35Cl

All isotopes can be determined for light masses

Light elements can be well quantified (N content 0.05±0.02 at.%)

Low energy heavy ion ERDA

ALD 8.6 nm Al2O3/Si Atomic layer deposited Al2O3 film on silicon (Prof. Ritala, U. of Helsinki)

Density of 2.9 g/cm3 and thickness of 8.6 nm determined with XRR (Ritala)

Elemental concentrations in the film bulk as determined with TOF ERDA are O 60±3 at.%, Al 35±2 at.%, H 4±1 at.%. and C 0.5±0.2 at.%

10 nm CNx on silicon TOF-ERDA results from sputter deposited 10 nm thick CNx hard coating on

Si. Measured with 6 MeV 35Cl beam and extreme glancing angle of 3°

A density of 2.0 g/cm3 was used in converting areal densities to nm

Effect of stripper gas pressure

13.6 MeV 63Cu7+ CaPO (hydroxyapatite)

Gas ionization detector Thin (~100 nm) SiN

window

Electrons for T2 timing signal emitted from the membrane

Future improvements: Gas ionization detector

TOF-E results from ETH Zürich

Incident ion 12 MeV 127I and borosilicate glass target

Nucl. Instr. and Meth. B 248 (2006) 155-162 200 nm thick SiN membrane from Aalto

University, Finland, on 100 mm wafer

30 mm

Gas ionization detector to replace Si-energy detector Why try to fix a well working system?

Greatly improved energy resolution for low energy heavy ions → heavier masses can be resolved

Gas detector is 1D position sensitive by nature → possibility for kinematic correction and therefore larger solid angles possible

Gas detector does not suffer from ion bombardment

10.2 MeV 79Br 8.5 MeV 35Cl

Recoil ranges in isobutane

Gas ionization detector develoment – See posters!