Cryogenic Particle Detectors Instrumentation Frontier Community - - PowerPoint PPT Presentation

Cryogenic Particle Detectors

Instrumentation Frontier Community Meeting (CPAD) Argonne National Laboratory - Jan 9-11, 2013 Blas Cabrera - Spokesperson SuperCDMS Physics Department Stanford University (KIPAC) and SLAC National Accelerator Center (KIPAC) References: LTD13 (2009) - SLAC http:/ /ltd-13.stanford.edu LTD14 (2011) - Heidelberg http:/ /ltd-14.uni-hd.de LTD15 (2013) - Caltech June 24-28, 2013

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

TES sensors invented by DOE HEP program

Original motivation was search for Dark Matter funded by DOE HEP at Stanford + NIST SQUIDs Breakthourgh in 1995 when Kent Irwin suggested voltage bias negative feedback Rapidly implemented in CDMS Dark Matter Rapidly implemented in x-ray astrophysics and materials studies at NIST, Goddard and beyond Implemented in CMB by Adrian Lee in 1996 Implemented in IR-optical-UV sensors in 1998 DOE HEP should take credit for these spin offs

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Original Motivation: Neutrinos & Dark Matter ! - wanted better resolution for large mass ! - now for CMB & IR-Optical-Xray ! - for Cosmic Frontier & Intensity Frontier

Thermal detectors with NTD Ge sensors (T) Thermal sensors with doped semiconductors (T) Superconducting Tunnel Junctions (E) Superconducting Transition Edge Sensors (T) Superconducting Kinetic Inductance Devices (E)

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

WIMP Search Sensitivity

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future past 5 yrs x10 courtesy of Vuk Mandic

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Discrimination strategies

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~10% ~ 1 % 1 %

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Intrinsic Resolution

Phonon and Ions (CDMS, EDELWEISS) Scintillation and Ions/Phonons (XENON, CRESST)

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Quanta E0 % Equanta Ne/keV NN/keV Noiseamp ΔEe-FWHM ΔEN-FWHM Phonons 100% 1 meV 1000000 1000000 0.1 keV 0.1 keV 0.1 keV Ions 10% 1 eV 300 100 1 keV 1 keV 3 keV Photons 1% 10 eV 10 1 0.01 keV 1 keV 10 keV

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

NaI -> HPGe -> µcalorimeters

Cryogenic Sensors For High-precision Safeguards Measurements weblink

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Scope of Cryogenic Detectors

Sub-Kelvin Sensor types

Transition Edge Sensors (T) Kinetic Inductance Detectors (E) Metallic Magnetic Calorimeters (T) Novel detection techniques

Technologies

Micro-fabrication with superconducting materials Cryogenics using dilution refrigerators and ADRs Multiplexing, SQUIDs, readout, & data analysis Particle absorbers & antennas: physics & design considerations

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Large TES arrays progressing

1,280-pixel SQUID TDM multiplexer for the SCUBA-2 weblink

MUX chip has 32 columns each with 40 multiplexed SQUIDs

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50 X 50 mm2

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Detectors and Physics

Detector Physics

Insulators - Debye heat capacity ~T3 at low temperature Conductors - Fermi liquid theory ~T at low temperature Semiconductors - electrons & holes ~ 1eV excitation Superconductors - quasiparticles ~ 1meV excitation Magnetism - paramagnetism and diamagnetism

Science applications

Neutrino mass experiments (IF) Dark matter searches (CF) Alpha & beta spectroscopy, mass spectroscopy, heavy ions, and neutrons X-ray & gamma spectroscopy in atomic, nuclear, astrophysics & other fields UV-optical-IR single photon detection Bolometers in mm / sub-mm wave for astrophysics, THz applications (CF)

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Calorimeter Principle

particle

thermal bath

absorber weak thermal link thermometer : phonons electrons spins tunneling states quasi particles

Thermal relaxation time: Thermal conductance

t

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Semiconducting Thermistors

R T

Si – ion-implanted (P,B) Ge NTD ( Neutron-Transmutation-Doped) +

• JFET

Thermistor

Ibias particle 100 K

High impedance device

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Electro-thermal feedback

• K. D. Irwin, Appl. Phys.
• Lett. 66, 1945 (1995)

shunt TES V SQUID

Superconducting Transition Edge Sensor (TES)

R T Materials Mo/Cu Ir/Au W

self regulated working point t I heat input: RTES goes up joule heating decreases fast response time

X-ray

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Metallic Magnetic Calorimeter (MMC)

Au:Er Au:Yb Ag:Er Bi2Te3:Er PbTe:Er LaB6:Er

dc SQUID

H

M T main differences to resistive calorimeters: non-contact readout no dissipation due to readout current

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

So what is intrinsic resolution for thermal detectors ?

Heat capacity C at temperature T has energy CT The average energy per carrier ~kT So there are N ~ CT / kT carriers So statistical thermal noise But we can detect smaller signal as shown

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ΔE

( )rms  kT

N = kT 2C

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Signal and Noise

Energy fluctuation is not energy resolution

✓ f ◆ p 2 C

McCammon

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ΔE = 2π fc Δf ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

1 2

kBT 2C; fc = G 2πC

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Signal & Noise

But finite thermalization time and amp noise so limited

p

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ΔE = 2π fc Δf ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

1 2

kBT 2C; fc = G 2πC

Δf

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Many ways to measure temperature (Kα1 / Kα2 for 55Fe at 6 keV)

Transition Edge Sensors (TES) Doped semiconductors - Si and NTD Ge Doped paramagnetism - MMC

ΔE

( )rms =

kBT 2C 8 τ 0 τ1 ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

1 4

ΔE

( )rms =

kBT 2C 4 α ΔE

( )rms =

kBT 2C 40

( )

1 4

α

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Non-equilibrium versus Equilibrium Detectors

Non-equilibrium detectors have an energy gap which is much larger than kT and allows long-lived excitations which we count.

photons from scintillator (~2% Etotal) - phototubes to count photons e-h in a semiconductor (~30% Etotal) - measure total charge quasiparticle (e’ s) in superconductor (~40% Etotal) - measure STJ, KID or TES

Equilibrium detectors are weakly coupled to thermal bath so thermal equilibrium is reached

Insulators with Debye heat capacity Conductors with Fermi heat capacity CV = γ T + αT 3

CV  N k 12π 4 5

( ) T TD

( )

3

electrons phonons 19

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Radiation interacting with Matter, e.g. Si

Electron energy loss processes:

For EK > 10 eV loss e-e collisions For Egap < EK < 10 eV loss through e-h pair production For Eopt < EK < Egap

• ptical phonon loss

For Es < EK < Eopt acoustic phonon loss For EK < Es no loss, but in E-field continual acoustic phonon emission with vdrift

60 keV photon recoil electron recoil electron 60 keV photon

Si

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• 20

20

• 20

X axis (µm) Y axis (µm) Z axis Depth (µm)

20 40 60

10-6 10-4 10-2 100 102 104 10-5 10-3 10-1

Stopping Power (eV/µm)

101 103 105 107

Electron Energy (eV)

Bethe-Bloch

• ptical

phonons acoustic phonons

Si

Ashley Vavilov

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Semiconductor diodes

Along track of primary electron cloud of e-h

some recombine close to track and are lost the rest separate in the E-field and move to opposite electrodes

Excellent x-ray and gamma spectrometers

Si diodes operate at 300K (gap 1.2 eV) Ge diodes operate at 77K (gap 0.7 eV)

Energy resolution given by counting statistics

Number of e-h pairs but where and Also find but better where the Fano factor thus Obtain for Si diodes

N ≠ E Egap N = E ε εSi = 3.7 eV εGe = 3.0 eV ΔE

( )rms ≠ ε

N = ε E ΔE

( )rms =

ε F E F ≈ 0.1 ΔE

( )rms =

ε F E < Egap E < ε E ΔE

( )FWHM = 120 eV @ 6 keV

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Fano factor ‘crazy carpentry’

F = Varcorr/VarPoisson F always < 1 due to correlations forced by energy conservation. Simple example has one type of excitation and equal probability for any energy partition at each step in cascade.

100 200 300 400 500 600 700 800 900 1000 10 20 30 40 50 60 70 80 Mean = 746.81; σcorr = 6.00; σPoisson = 27.33; Fano = 0.048; Number of Excitations Number of Events

excitations phonons

Roosbroeck PR139, A1702 (1965)

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Superconducting Tunnel Junction (STJ)

I V

2Δ

S1 S2 non-thermal – fast detector specially suited for low-energy photons thermal background

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Kinetic Inductance Detectors: KID

E P f

after photon absorption

δf non-thermal fast detector well suited for frequency domain multiplexing

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Quasiparticles

Quasiparticles are electron-like excitations in superconductors from breaking Cooper pairs

Element Tc(K) Egap(meV) (ESi/Egap)1/2 Nb 9.5 1.47 28 Ta 4.47 0.7 41 Al 1.14 0.17 84 Ti 0.39 0.06 140 Hf 0.13 0.02 245

Day JPL

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

TES versus STJ or KID

Intrinsic resolutions are similar because non- equilibrium detectors have excitations given by gap which is ~kTc whereas thermal detectors have quanta with average ~kTc

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Types of TES Detectors

Direct absorption of photon into TES (e. g., optical photon detectors) Photon absorber in electrical contact with TES (e. g., x-ray detectors) Large mass absorbers generate phonons which are converted into quasiparticles which diffuse to the TES (e. g., dark matter detectors)

W Si or Ge 1−10 eV photon Bi Al/Au Si3N4 1−10 keV x-ray Si or Ge Al W γ, n or WIMP

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

TES Thermal Model

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• Electrothermal Feedback

– Voltage bias intrinsically stable – Fast response – High Sensitivity CelW CphW CphSi TelW TphW TphSi PJ Gep GWSi GSiCu Cu

electron-phonon bottleneck

C dT dt = V

B 2

R ! " Te

n ! T ph n

( ), n = 5

!etf = !0 1 + " n , !0 = C g , g = n # T

e n-1

!EFWHM = 2.355 4 kB T

e 2 C n 2 " = 2.355 4kBTe P J # etf n 2

For Esat ~ C T

e " = P J # etf

( ) =10 keV then !EFWHM =1.1 eV

For Esat ~ C T

e " = P J # etf

( ) =1 eV then !EFWHM =11 meV

phonon noise

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Lower threshold for better resolution

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Higher Resolution with Lower Saturation

bias point pulse saturation Rn=3.2 W Rn=3.2 W bias resistance bias power Rn=3.2 W

!EFWHM = 2.355 4 kB T

e P0 "etf n 2

for E < Esat = P0 "etf !EFWHM # 2.355 4 kB T

e E n 2

for E > Esat

But, must deal with pulse shape variation with energy

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Optical photon absorbed in TES (Tali Figueroa)

TES Simulation

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Optical Photon Detectors

Demonstration of W TES sensitivity

• Appl. Phys. Lett. 73, 735 (1998)
• B. Cabrera, R. Romani, A. J. Miller
• E. Figueroa-Feliciano, S. W

. Nam

active W sensor Al voltage rails

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Optimize QET design

Detailed testing of fabrication techniques using 2.6 keV x-rays allow us to measure the quasiparticle trapping length and the transmission from Al fins to W TESs

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Al fin W TES 1 W TES 2 W TES 3 TES 3 Energy [keV]

• J. Yen,
• B. Young,
• P. Redl

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

iZIP interleaved charge & phonon design

Interleaved electrodes and phonon sensors

• n both sides of

the detector. Alternating +2V / ground on one side and -2V / ground on the

• pposite side

with phonon sensors at ground potential

• n both sides.

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

iZIP interleaved charge & phonon design

Interleaved electrodes and phonon sensors

• n both sides of

the detector. Alternating +2V / ground on one side and -2V / ground on the

• pposite side

with phonon sensors at ground potential

• n both sides.

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

iZIP interleaved charge & phonon design

Interleaved electrodes and phonon sensors

• n both sides of

the detector. Alternating +2V / ground on one side and -2V / ground on the

• pposite side

with phonon sensors at ground potential

• n both sides.

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

iZIP interleaved charge & phonon design

Interleaved electrodes and phonon sensors

• n both sides of

the detector. Alternating +2V / ground on one side and -2V / ground on the

• pposite side

with phonon sensors at ground potential

• n both sides.

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

CDMS Tc Gradient Problem

Voltage biased TES sensors where invented to solve the Tc gradient problem for large area sensors

• 20
• 10

10 20

• 0.05
• 0.04
• 0.03
• 0.02
• 0.01

0.01 0.02 0.03 0.04 0.05

Bias Current [µA] Sensor Current [µA]

• 20
• 10

10 20 10 20 30 40 50

Bias Current [µA] Sensor Resistance [ohms]

• 20
• 10

10 20 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Bias Current [µA] Sensor Power [fW]

• 20
• 10

10 20 5 10 15 20 25 30 35 40 45

Bias Current [µA] Sensor Power [fW]

65 70 75 80 85 10 20 30 40 50

Temperature [mK] Sensor Resistance [ohms]

With current bias, there did not exist a bias temperature for all, but with self voltage biasing all at high sensitivity.

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

N/S Phase Separation along TES

• 1000
• 500

500 1000

• 2.5
• 2
• 1.5
• 1
• 0.5

0.5 1 1.5 2 2.5

Bias Current [µA] Sensor Current [µA]

• 1000
• 500

500 1000 5 10 15 20 25 30

Bias Current [µA] Sensor Resistance [ohms]

• 1000
• 500

500 1000 5 10 15

Bias Current [µA] Sensor Power [pW]

• 20
• 15
• 10
• 5

5 10 15 20 10 20 30 40 50 60 70

Voltage [µV] Sensor Power [pW]

Analytic solution assuming sharp transition and constant conductivity See linear downward slope instead

• f flat

power region.

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CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University 39

Phonon thermalization process

diffusive phonons are localized -> ballistic phonons distribute uniformly two separate events

• n left and right

hand side top is top side and bottom is the bottom side note that after 500 µs all channels identical position information in leading part

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soon GEANT4 framework

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Advanced iZIP Detectors

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• nization readout.

X [mm] Z [mm] −2 −1 1 2 1 2

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Two detectors with one 210Pb decay every min

• perated for 20 live days corresponds to more

than total 210Pb events for SuperCDMS Soudan and even for future 200 kg SuperCDMS SNOLAB

210Pb Surce Data from SuperCDMS Soudan

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206Pb 103 keVnr end pt

10 keVee line 1keV FWHM

CPDA - Cryogenic Particles Detectors Page Blas Cabrera - Stanford University

Summary

Original science motivations for cryogenic detectors were neutrinos and dark matter, but great success in many other areas continuing to the present day. Many recent advances in single sensor performance and more importantly in large array performance. Continued improvements in our fundamental understanding of these devices including non-equilibrium nature of TESs Encourage those interested to attend LTD15

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