Calorimetric Low Temperature Detectors FAIR for Applications in - - PowerPoint PPT Presentation
Calorimetric Low Temperature Detectors FAIR for Applications in NUSTAR Peter Egelhof GSI Helmholtzzentrum fr Schwerionenforschung, Darmstadt, Germany and University Mainz, Germany NUSTAR Annual Meeting 2016 GSI, Darmstadt February 29 -
calorimetric detector
particle or photon phonons thermometer
°
potential advantage:
⇒ various applications in many fields of physics secondary: thermalization: conversion of energy to heat ⇒ detection of thermal phonons ⇒ calorimetric detectors interaction of radiation with matter: primary: ionization, ballistic phonons (conventional ionisation detectors) The success of experimental physics and the quality of the results generally depends on the quality of the available detection systems !
Atomic and Nuclear physics:
⇒ high energy resolution
⇒ high energy resolution ⇒ good energy linearity Astrophysics:
⇒ low detection threshold
⇒ low detection threshold
⇒ high energy resolution Particle physics:
⇒ absorber = source ( 130Te)
⇒ absorber = source ( 187Re) for more detailed information see:
Topics in Applied Physics 99 (2005)
Low Temperature Detectors, JLTP (2014), 320 participants! Applied physics:
⇒ high energy resolution
⇒ high energy resolution
incident particle with energy E T ⇒ ⇒ ⇒ ⇒ T + ∆ ∆ ∆ ∆T absorber C thermometer R (T) heat sink thermal coupling k
detection principle:
t2 t1
time
∆T
thermal signal: amplitude: ∆T = E/C (C = c • m = heat capacity) rise time: τ1 ≥ τtherm (≈ 1 – 10 µsec) fall time: τ2 = C/k (≈ 100 µsec – 10 msec)
R T
b) thermometer: for thermistor (bolometer): ∆T → ∆R → ∆U ⇒ maximum sensitivity for large dR/dT – semiconductor thermistor due to appropriate doping ⇒ exponential behavior of R(T) – superconducting phase transition thermometer a) absorber: maximum sensitivity ∆T = E/mc for – small absorber mass m – small specific heat c due to: c = α T + β (T/θD)3 (θD = Debye-temperature) electrons lattice ⇒ low operating temperature ⇒ „low-temperature detector“ (αT dominating for T ≤ 10K ⇒ insulators (α = 0) or superconductors)
⇒ optimize radiation hardness, absorption efficiency, etc.
. . . . det .
electr phon phon electr semicond r calorimete
⇒ better statistics of the detected phonons
semiconductor detector: ω ≈ 1 eV calorimetric detector: ω ≤ 10-3 eV
energy deposited in phonons and ionisation contributes to the signal (for ionisation detectors: losses up to 60-80% due to: - recombination
for ideal calorimetric detector:
noise thermodynamic fluctuations
5
B
example: 1 MeV particle in a 1 mm3 sapphire absorber ⇒ for low temperature: microscopic particle affects the properties of a macroscopic absorber
copper coldplate low temperature varnish aluminium- thermometer absorber slit heavy ions
R
L
U
signal heat sink
Detector Design and Perfomance: absorber: sapphire-crystal: V= 3 x 3 mm² x 430 µm thermometer: aluminium-film (d = 10 nm), TC≈1.5°K (in the range of a 4He-cryostat) (for impedance matching to the amplifier: ⇒ meander structure) readout: conventional pulse electronics +Flash-ADC`s +Digital Filtering
for an overview see: P.E. and S. Kraft-Bermuth,
copper coldplate low temperature varnish aluminium- thermometer absorber slit heavy ions
R
L
U
signal heat sink
Detector Design and Perfomance: absorber: sapphire-crystal: V= 3 x 3 mm² x 430 µm thermometer: aluminium-film (d = 10 nm), TC≈1.5°K (in the range of a 4He-cryostat) (for impedance matching to the amplifier: ⇒ meander structure) readout: conventional pulse electronics +Flash-ADC`s +Digital Filtering
for an overview see: P.E. and S. Kraft-Bermuth,
1.60 1.62 1.64 1.66 50 100 150
super- conducting normal state R [kΩ] T [K] transition region: dR/dT ≈ const
temperature
detector array:
stabilization in operation
3 mm cryostat absorber aluminum thermometer heating resistor CLTD-array detector pixel:
3 x 3 x 0.43 mm3 sapphire (Al2O3)
Transition Edge Sensor (TES) 10 nm thick meander shaped Al-layer ⇒ photolithography (high purity!!)
Au/Cr strip
T
c = 1.5 – 1.6 K
beam line
number of pixels: 25 active area: 15 X 15 mm2
detector performance: response to 32S ions @ 100 MeV with UNILAC-beam: for 209Bi, E = 11.6 MeV/u ⇒ ∆E/E = 1.8 x 10-3 with ESR-beam: for 238U, E = 360 MeV/u ⇒ ∆E/E = 1.1 x 10-3 with Tandem-beam: for 152Sm, E = 3.6 MeV/u ⇒ ∆E/E = 1.6 x 10-3 rate capability: ≥ 200 sec-1 resolution: ∆E/E = 1.6 x 10-3 systematical investigation of energy resolution:
500 1000 1500
2 4 6
τrise = 35 µs τdecay= 150 µs
101.6 102.0 102.4 20 40 60 80
counts/bin E [MeV]
∆E/E = 1.6x10
∆E = 166 keV
⇒ for heavy ions: ≥ 20 x improvement over conventional Si detectors
energy resolution: example:
238U @ 20.7 MeV )
energy linearity: example:
13C, 197Au, 238U
5 10 15 20 25 800 1000 1200 1400 1600 1800 2000 2200 2400
peak position [channel] E [MeV]
10 20 30 40 50 60 70 1000 2000 3000 4000 5000 6000 7000 13C, 197Au, 238U
peak position [channel] E [MeV]
12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 30.0 200 400 600 800 1000 1200 1400 1600
counts/bin energy [MeV]
∆E = 91 keV calorimetric detector
12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 30.0 100 200 300 400 500
counts/bin energy [MeV]
∆E = 2808 keV conventional Si - detector 4He 13C 197Au 238U 4He 13C 197Au 238U
for conventional ionization detector: high ionization density leads to charge recombination (E- and Z- dependent) ⇒ pronounced pulse height defects ⇒ nonlinear energy response ⇒ fluctuation of energy loss processes ⇒ limited energy resolution
potential applications: ⇒ investigation of multi phonon giant resonances ⇒ reactions at low energies (LEB at FAIR) nuclear spectroscopy:
⇒ identification of reaction channels Example: investigation of giant resonances (collective excitation of nuclear matter)
1900 1920 1940 1960 10 100 1000
elastic scattering
giant resonance expected
events / channel energy [MeV]
NatPb (20Ne, 20Ne’), E = 100 MeV/u
(CLTD adjusted to range of Ne ions)
1E-4 1E-3 0.01 0.1 1 10 100 1000 20 40 60
stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] electronic nuclear "Bragg- Peak"
example: stopping power of 238U-ions in gold (SRIM-prediction)
energy loss processes:
= ionization of target atoms
= elastic scattering on target nuclei important: theoretical understanding
interaction of energetic particles with matter
material science investigation of radiation damage medicine → tumor therapy … problem: accuracy of theoretical models unsatisfactory ⇒ predictions by semi-empirical computer codes use best fits on experimental data (example: SRIM) ⇒ many data needed for different kind of targets, projectiles, energies in particular: data for very slow and very heavy ions are still scarce
without target with target pulse height energy detector [a.u.] ToF [a.u.]
as compared to previous measurements with conventional energy detector (for example: Trzaska et al., Zhang et al.): ⇒ by use of CLTD’s as energy detector: improved energy resolution → higher sensitivity improved energy linearity (no pulse height defect) → reduced energy calibration errors broad energy distribution heavy ions ToF-detector target ∆x energy detector (CLTD)
input energy Ein
measurements JYFL Jyväskylä in cooperation with H. Kettunen, W. Trazka et al. experimental setup:
example: 131Xe in 53 µg/cm² carbon
10 20 30 40 50 60 70
2 4 6
∆E = Ein - Eout [MeV]
Ein [MeV]
without target with target
131Xe-ions
2 MeV/u
degrader
ToF 0.9 m
target wheel CLTD
array
magnet target thickness ∆x determined by weighting + energy loss of α-particles → high accuracy
1 2 3 4 5
2000 4000 6000
without target with target
counts/bin
∆E = Ein - Eout [MeV]
<∆E>
0.1 1 20 40 60 80 100
present data Trz09 Gs98 Pap78 Bi80 SRIM 2008 CasP 5.0 PASS 6.83
electronic stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] Xe in C
agreement with Geissel et al. deviations from data from Trzaska et al. and Pape et al.
reference data taken from online database of H. Paul: http://www.exphys.jku.at/stopping/
experimental uncertainties:
(lowest energies:
(improvement of factor 2-3) <1 % 3 % <0.5 % <2 %) 3 – 4 %
0.1 1 20 40 60 80 100
present data SRIM 2008
electronic stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] Xe in C
0.1 1 20 40 60 80 100
present data SRIM 2008 CasP 5.0 PASS 6.83
electronic stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] Xe in C
and A. Echler et al. J. Low Temp. Phys. 176 (2014) 1033 substantial deviations from SRIM-predictions (semiempirical calculations) data extended to lower energies
10 20 30 40 50 60 70 80 0.60 0.65 0.70 0.75 0.80 0.85 0.90
131Xe in gold 127I in gold (Datz et al. 1)
(110) planar channel ∆E(channeling)/∆E(random)
energy [MeV]
for thin Ni- and Au-targets: → double-peak structure in measured energy loss
example: Xe (13 – 15 MeV) in Au (363 µg/cm²)
“channeling energy loss” “random energy loss”
1 2 3 250 500 750 1000 1250 1500 1750 2000 20 40 60 80 100
without target with target
counts/bin energy loss ∆E [MeV]
explanation:
1)Datz et al., Nucl. Inst. Meth., 38 (1965) 221 10 20 30 40 50 60 70 80 0.60 0.65 0.70 0.75 0.80 0.85 0.90
∆E(channeling)/∆E(random)
energy [MeV]
and
to be published ⇒ new data on channeling energy loss obtained ⇒ source of systematic error identified and eliminated
20 40 60 80 100 120 10
110
210
310
4counts detector position [°2θ]
gold
10
110
210
3nickel
counts
10
110
210
3carbon
counts
amorphous polycrystalline random orientation Is the interpretation of the data correct? channeling appears only in crystalline absorbers! problem: targets not grown as single crystals the X-ray analysis confirms polycrystalline structure in Ni and Au foils polycrystalline random orientation the channeling effect is enhanced due to much stronger multiple scattering for random energy loss
0.1 1 10 20 30 40 50
CLTDs Trz09 Gs98 Bi80 SRIM 2008 CasP 5.0 PASS 6.83
electronic stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] Xe in Ni
experimental uncertainties:
(lowest energies:
substantial deviations from SRIM-predictions agreement with Geissel et al. deviations from data of Trzaska et al. for low energies
reference data taken from online database of H. Paul: http://www.exphys.jku.at/stopping/
<1 % 3 % <1 % <2 %) 3 – 4 %
0.1 1 10 20 30 40 50
CLTDs SRIM 2008
electronic stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] Xe in Ni
0.1 1 10 20 30 40 50
CLTDs SRIM 2008 CasP 5.0 PASS 6.83
electronic stopping power [keV/(µg/cm²)] energy per nucleon [MeV/u] Xe in Ni
2 arg 2 2
e ch coll
1. Measure energy-loss distribution at different energy domains in solids (broad f(q) up to q=Z1) 2. Target homogeneity better than 10-3 3. Energy measurements better than 10-3 independent on the quality of the incident beam.
transparency from H. Geissel
t1 E t2 heavy ion important for many applications: isotope mass identification for conventional setups: mass resolution is limited by energy resolution! ⇒ calorimetric detectors
2
energy ⇒ E TOF ⇒ v alternative method: disadvantage:
(especially for slow heavy ions!)
B • ρ ⇒ p TOF ⇒ v standard method:
2 2 2
energy ⇒ E TOF ⇒ v
65,63Cu ions
E = 50 MeV
TOF 1.2 m
electrostatic mirror MCP (chevron) calorimeter
∆t = 680 ps ∆E = 330 keV limitation in this experiment: TOF measurement !
60 62 64 66 68 100 200 300 400
counts/bin mass [u] FWHM = 0.9 amu
measured at Tandem accelerator at MPI in Heidelberg
63,65Cu ions @ 50 MeV
2
2 2 2
t ∆t 2 E ∆E m ∆m + =
PHD Thesis 2013
60 80 100 120 140 160 50 100 150 200 250 300 350
calorimeter energy [MeV] ToF [ns]
234 236 238 240 242 100 200
counts/bin mass [amu]
FWHM = 1.28 amu low energetic 238U ions @ UNILAC accelerator at GSI
TOF 1m calorimeter thick scatterer
238U ions
3.6 MeV/u
experimental setup: → broad energy distribution (0 - 3.6 MeV/u) energy range: 65 - 150 MeV
∆t (FWHM) = 250 ps
not reachable with conventional E-ToF system advantage to Bρ-ToF method: ▪ high dynamic range ▪ not affected by charge state ambiguities
238U
∆m (FWHM) = 1.28 u
@ 90 MeV: ∆t/t = 2.0 x 10-3 ∆E/E = 3.5 x 10-3
In-Flight Mass Identification for:
(for slow heavy ions: no charge state ambiguities, high dynamic range) ⇒ potential application at NUSTAR@FAIR: LEB ⇒ investigation of deep inelastic transfer reactions (proposed by S. Heinz)
⇒ potential application at NUSTAR@FAIR: HISPEC (LYCCA)
feed a known α-chain): ∆m ≤ 1 for m = 300 reachable
⇒ high sensitivity first experiment performed: trace analysis of 236U at the VERA facility at Vienna:
different A with equal Z
transparency from J. Gerl Idea: replace CsI energy detector by a CLTD
In-Flight Mass Identification for:
(for slow heavy ions: no charge state ambiguities, high dynamic range) ⇒ potential application at NUSTAR@FAIR: LEB ⇒ investigation of deep inelastic transfer reactions (proposed by S. Heinz)
⇒ potential application at NUSTAR@FAIR: HISPEC (LYCCA)
feed a known α-chain): ∆m ≤ 1 for m = 300 reachable
⇒ high sensitivity first experiment performed: trace analysis of 236U at the VERA facility at Vienna:
calorimetric detector: (semiconductor detector: ∆E/E ≥ 5 •10-2) ultrathin 12C-foils + channelplates (energy straggling in 12C-foils negligible!)
3
10 3 2 E ∆E
−
⋅ − ≈
2 2 2
3
10 1 v ∆v
−
⋅ ≤
for Z ≥ 112: decay chains do not feed a known α-chain ⇒ mass identification of the superheavy nucleus required calorimetric detector
3
−
t1 E t2 TOF
Separator
Z = 116 - nucleus E ≤ 0.3 MeV/u
for m = 300 ⇒ ∆m ≤ 1 amu
In-Flight Mass Identification for:
(for slow heavy ions: no charge state ambiguities, high dynamic range) ⇒ potential application at NUSTAR@FAIR: LEB ⇒ investigation of deep inelastic transfer reactions (proposed by S. Heinz)
⇒ potential application at NUSTAR@FAIR: HISPEC (LYCCA)
feed a known α-chain): ∆m ≤ 1 for m = 300 reachable
⇒ high sensitivity first experiment performed: trace analysis of 236U at the VERA facility at Vienna:
17.0 17.2 17.4 17.6 17.8 18.0 1 2 3
236U: 13 + 4 counts 238U: 2 counts 235U: 6 + 3 counts
counts energy [MeV]
results: substantial improvement in background discrimination and detection efficiency ⇒ level of sensitivity improved by one
236U/238U = 7 x 10-12
application for Accelerator Mass Spectrometry: (in collaboration with: R. Golser, W. Kutschera et al., VERA facility, Vienna) aim: determination of very small isotope ratios 236U/238U in natural uranium samples ⇒ 236U known as monitor for flux of thermal neutrons (for example: investigation of Natural Reactors in Uranium Mines)
⇒ capture of a thermal neutron ⇒ binary scission ⇒ about 85% (~170 MeV)
is transferred to the kinetic energy of the fragments
⇒ better understanding of the nuclear fission process ⇒ test of theoretical predictions ⇒ information about nuclear structure (shell effects, excited states, ...) ⇒ data relevant for reactor physics (for example for Fukushima – Accident)
(absorber method, see also U. Quade et al., NIM A164 (1979) 436
(instead of conventional ionization chamber)
∆E ~ Z2 ERest (Z-dependent)
The LOHENGRIN Mass Separator Z - Identification via the Absorber Method
by n → 235U
to A/Q (magnetic field) and E/Q (electric field)
Quality of Z – Separation depends on:
LOHENGRIN: fixed E,A,Q
⇒ stable beams of 109Ag (E = 80 MeV) and 127I (E = 68.7 MeV) (at same velocity)
⇒ first test of the new 25 pixel array ⇒ check of quality of Z – separation dependent on:
∆E = 330 keV (∆E/E = 0.5 %)
10 20 30 40 50 60 0.0 0.5 1.0 1.5 2.0 2.5 3.0
absorber foils: C8H7Cl Si3N4 C FWHM [MeV] energy loss [MeV]
109Ag (E0 = 68.7 MeV)
(Parylene C)
results:
Experimental Setup:
fission fragments
well defined mass, energy, charge state
Motivation:
for an accurate determination of the 92Rb yield: ⇒ take into account dependence on energy and charge state ⇒ many systematic measurements needed data analysis in progress
■ CLTD + Si3N4 (present data) □ CLTD + Si3N4 (test at Garching) ○ IC + Parylene-C (Quade et al.) ◊ IC + Parylene-C (prediction by Bocquet et al.)
80 90 100 110 120 130 140 10 20 30 40 50 60 70
Z/∆Z mass A
accessible with conventional techniques
NUSTAR Seminar 27.01.2016 Heavy Ion Detection with CLTDs Artur Echler
⇒ needed for a better understanding of the fission process data analysis is in progress
up to date unexplored region (data analysis in progress)
improve the detection efficiency (absorber foils directly in front of the CLTD`s, inside the cryostat) improve flexibility (moveable absorber foils of different thickness) investigate the (low intensity) symmetry region of fission fragments which is
investigate yields for 96Y (important for the understanding of antineutrino spectra), proposal of H. O. Denschlag et al.
Santwana Dubey1,2, Artur Echler1,2,3, Peter Egelhof1,2, Herbert Faust6 , Friedrich Gönnenwein5, Jose Gomez4, Ulli Köster6, Saskia Kraft-Bermuth3, Manfred Mutterer5, Pascal Scholz3, S. Stolte2
CLTD`s have substantial advantage over conventional detection systems concerning resolution, linearity, etc. CLTD`s for Heavy Ion Physics have been designed and used successfully for experiments the results on Z-distributions of fission fragments are expected to provide important information for nuclear structure-, reactor- and neutrino physics CLTD`s were also applied successfully in AMS, stopping power measurements, in-flight mass determination and Lambshift measurements, and have the potential for many further applications, as for example for SHE research