1 CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010 1 5 Commissariat à l'Energie Atomique et aux...
-
Upload
adelia-sharlene-wheeler -
Category
Documents
-
view
212 -
download
0
Transcript of 1 CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010 1 5 Commissariat à l'Energie Atomique et aux...
1CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010 1
5Commissariat à l'Energie Atomique et aux Energies Alternatives, Gif-sur-Yvette, 91191, France6Instrumentation Technologies d.d., Solkan, 5250, Slovenia7GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, 64220, Germany
1SLAC National Accelerator Laboratory, Menlo Park, CA. 94025, USA 2European Synchrotron Radiation Facility, Grenoble, 38043, France3Ohio State University, Columbus, OH. 43210, USA4Deutsches Elektronen-Synchrotron, Hamburg, 22607, Germany
X-ray beam position and intensity monitoring using single crystal diamonds
J Morse1, 2, M Salomé2, J Härtwig2,H Kagan3, H Graafsma4, M Pomorski5, B Solar6, E Berdermann7
2CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
1. X-ray Synchrotron (and XFEL) beam monitoring : requirements, and why diamond?
2. Material and processing: still-unresolved problems
3. Quadrant device beamline tests at ESRF with ‘dc’ electrometer readout
4. DESY tests with RF position readout
Outline
5. Measurements with high heat load ‘white’ beams:some recent results courtesy John Smedley and Jeff Keister (BNL)
3CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
3rd+ generation synchrotrons (ESRF; APS; SPring8… NSLSII)
ESRF Ø300m
~ 50 beamlines
Beam position - intensity monitors
white/pink beam 0.2~2kW
monochromatic beam ~mW
undulator source
50 …1km
source to end station
4CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
X-ray beamline monitoring requirements
monochromatic beams : max. absorbed X-ray power: ≤ few mW, OKbut beam power ≥100Wmm-2 (C-W) for synchrotron ‘white’ beam applications;also ‘pulse ablation threshold’ for focused XFEL beams:
ONLY possible with diamond
accuracy & linearity requirement ≤ 1% (sometimes <.01%, relative)Intensity:
required beam stability ~10% of beam size 0.1 ~ 50μm, nanofocusing goals 10nm synchrotron measurement rates required dc ~ 1kHz (acoustic vibrations!) for XFELs ‘single shot’ measurements needed.
Position
synchronization with XFEL pulse and optical lasers in synchrotron pump probe experiments synchrotron X-ray photon bunches ~50psec at 105~108 pulses/sec XFEL photon bunches <10fsec at 102… 103 pulses/sec
Timing:
minimal beam interference: absorption, coherence loss, scatteringbeamline compatibility: package size, operation in air, dirty-vacuum, clean-UHVionizing radiation load >104 Gray/sec
device…
5CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
beam
Electronicsbox
SLAC-LCLS ‘4th generation’ free electron laser source
Sample light scatter problems foreseen with intense optical laser pump-probe experiments. Use simpler, more accurate (better photon statistics efficiency) diamond monitors?? …but need thin ~10µm diamond films with excellent surfaces (!! beam coherence preservation!!)
Beam diagnostic system: amorphous Si3N4 film targets of 0.05…4µm thickness used to scatter fraction of XFEL beam onto silicon diodes ~2-9keV beam, pulse-by-pulse (60-120Hz) beam intensity/position measurement with custom 10µs gated integrator electronics.
Si3N4 membrane
D
B
10x10 mm2
5x5 mm2
10 mmSi DiodesA, B, C, D
XFEL pulsed beam
A C
Courtesy Yiping Feng, SLAC-LCLSSi3N4 thin targets
Array Si diodes
beam
6CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
why diamond for X-ray beam monitoring?
0 10 20 30
10
100
1000
Th
ickn
ess
fo
r 5
% a
bso
rptio
n
(m
icro
ns)
X-ray energy (keV)
Diamond (Z= 6) Silicon (Z= 14)
~practical limitssingle crystal CVD
…and short range of photoelectric- or Compton-electron
Z = 6 low specific X-ray absorption: little beam absorption and scattering…
- ‘zero’ leakage current high E-fields possible < nsec response
- simple ‘all diamond’ devices can be radiation hard
- outstanding thermal conductivity/ thermal shock resistance 273°K conductivity diamond is 2000, cf. Si 150 Wm-1 °K-1
7CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
• diamond plate, thin (30…500µm) diamond with ‘X-ray transparent’ <100nm surface contacts Cr, Ti, … Ni, Al (Au, Pt, W))
DCBA
DCBAY
DCBA
DBCAX
Y
XA B
C D
position (and intensity) found with…
multiple electrodes:
exploits diffusion splitting (~10µm) of charge
e.g. simple quadrant motif
difference/sum of electrode currents A, B, C, D givesbeam 'centre of gravity’
sum of currents gives beam intensity
operation of diamond XBPM devices
• in beam, diamond bulk acts as solid state ‘ionization chamber’ electron thermalization range ~few µm
charge diffusion ~10µm
duo- or tetra-lateral resistive electrodes
linear position response over several mm
(but may be less precise: electronic noise…)
following talk of M Pomorski
• current signal readout ‘DC’ up to synchrotron RF clock frequencies ~500MHz possible
8CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
~1mm
Single crystal CVD material
Polycrystal sample,on same scale
Single Crystal: excellent spatial uniformity withPrompt, ‘unity gain’ charge collection (needs non-injecting contacts)
Polycrystalline:grain-boundaries ~ size of X-ray beams !alsotrapping and local field distortions, signal response lagX-ray scattering…
XBIC: signal current maps made from x, y raster scan of micron X-ray beam
XBIC, Poly- and single crystal response
1σ signal variation 0.103%over 100 point row
9CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
10 secCharge collection efficiency << unityincreases (prompt + detrapped components) with E field 1…5v/µm,
beam 15 x 100µm2 ,1.3 x 1012 ph/sec at 12keV
Ralf Menk, 2006 SLS data on polycrystalline ~10µm thick (material sourced by Diamond Materials, Freiburg)
measured ‘dc’ signal lag with fine-grain polycrystalline
such lag effects not easily seen in HEP ‘pulse shaped ’ charge measurements --less problematic (?) with a-c coupled readout methods
10CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Homoepitaxially [1,0,0] CVD grown diamond plates show clusters of threading dislocations that usually result in high localized leakage currents when the metal-contacted plate is biased.
Plates are screened for these defects by optical cross polarimetry andPlates with no defect ‘clusters’ show room temperature leakage currents <0.1pA/mm2 for applied fields beyond 5Vµm-1.
e6-D
DL
sam
ple
1586
(200
9)optical cross polarimetry X-ray topography
e6 CVD material, bulk crystal lattice defects
11CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
e6 CVD sample variability (2009, samples supplied via DDL)
4x10-5
8x10-5
Δn
white is ‘off scale’
Light propogation along [100]
12CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Surfaces: ‘scaife’ abrasive polishing
e6 optical grade CVD [100], scaifed at DDK
rms factor of 7 between two sides ! No explanation given (not a ‘controlled’ test)
5 x 5 µm2
RMS: 0.1 nm
5 x 5 µm2
RMS: 0.7 nm
AFM at IAF-Freiburg by Armin Kriele
13CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
543210
1.2
1
0.8
0.6
0.4
0.2
0
X[µm]
Z[n
m]
1-1122
32.521.510.50
5
4
3
2
1
0
X[µm]
Z[Å
]
Surface damage removal
scaife
history
scaife historyTapping AFM (ESRF),
e6 DDL1122 side A
Ar ion beam milling to a depth ≥ several µm removes scaife ‘microfracture’ damage,leaves surfaces with few Angstrom roughness over a micron length scale (right)(sample processed at Mintres BV, Cuijk)
Similar surface morphology possible with Ar-Cl ion etching
14CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Metal contact devices: patterning (I)
150µm
SEM at 5kV
~20nm+20nm Cr+Au contacts sputtered through laser-etched s/steel contact shadow mask (GSI)
Shadow masks:
useful only for ‘simple’geometric designs
limited precision, dependent on mask etch technique (laser, wet etch…)
-shadow mask is ‘consumed’ in process
white light microscopytransmission mode
-practical problems of mask clamping during evaporation or sputter of contacts: tapered edge thickness profiles; possible metal ‘migration’ under mask edge (mask contamination of diamond surface)
15CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
-200 -150 -100 -50 50 100
-5
5
beam off
upper left quadranty= 4.58, z=1.83
lower left quadranty= 4.58, z=3.27
bias (V)
cu
rre
nt
(nA
)
beam off
beam focussed 1 x 0.4µm2, absorbed flux ~2x107 photos/sec at 7.2keV
evaporated (?) Cr-Au contacted 100µm e6 plate, GSI shadow mask deposition (c. 2003)
- dark current measurement
- current under steady state X-ray illumination
contact/surface problems, I-V curves
?
‘dirt’ under contactsand/or diamond surface damage-300 -200 -100 100 200 300
-6
-5
-4
-3
-2
-1
1
2
3
4
5
6
~100nm Al
curr
en
t (n
A)
bias (V)
~100nm Al
0.5V
/m
bias
96m C*
sputtered Al contacts, 96µm e6 plate, GSI shadow mask deposition (2007)
X-ray calibration relative to Si diode (ESRF-GSI) εDiamond = 13.05 +/-0.2 eV/e-h pair
16CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Metal contact devices: patterning (II)
Lift off lithography:
-allows complex geometric designs: can implement many designs on single mask
-uses standard lithographic mask techniques: edge precision << 1µm*…but non-standard, small sample handling problems
-*limited by non-trivial problem of resist deposition, e.g. edge ‘beading’ with spin deposition of resist
ESRF-DESY-OSU mask set for XBPMs, 2010~100nm Al contacts, OSU-Kagan 2010
17CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Ni/Pt/Au and Ti(annealed)/Pt/Au contacts, Lithographic deposition at Stanford NanoFab’ Facility, Ch. Kenney (2006)
contact/surface problems
50m 1m
10
8
9
7
insufficient pre-cleaning of diamond surfaces!!
18CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
ESRF ID21, pinhole beam Ø100µm,
~108ph/sec at 7.2keV, e6 380µm
(Glasgow Univ., W. Cunningham, 2006)
Good lift-off contacts
ESRF ID09 beam ~50x100µm2, ~1011ph/sec at ~20keV, e6 390µm(OSU-Kagan, 2007), ~100nm Ti(5)W(95) alloy sputtered contacts
ESRF ID21 beam ~0.6x1.5µm2, ~4x109ph/sec at 7.2keV, e6 100µm(OSU-Kagan, 2010), ~100nm IBM surface, Al sputtered contactsnb. full charge collection for ~0.1Vµm-1
dark leakage current <0.1pA for +/-2Vµm-1
19CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Quadrant sensors
ESRF-ID21 Microscopy beamline project: very limited space, operation in high vacuum and air
IBM-etched e6 single crystals 4.2 x 4.2mm2, thicknesses 30 & 100µm
Rogers multilayer PCB, microcoax connectors for screened wire leadouts
direct bonding of diamond to PCB
Al electrode patterns and wire bonding (Kagan – OSU 2010)
sam
ple
piezo s
can
stag
e
focused beam
diamondquadrant BPM
10mm Initial ID21 beam line tests:
homogeneous response map seen on 3 samples tested no ‘hot spots’ <pA leakage currents
20CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Quadrant sensor, electrometer readout : position time scans
ESRF ID21 microfocus beam tracking 1sec/point: vertical beam jumps on synchrotron e-beam refills
X-ray flux ~108 ph/sec at 7keV (FZP optic):~ 20fC in diamond per X ray bunch
~ 10nA ‘dc equivalent’ signal current
0 5000 10000 15000 20000 25000 30000 35000
-1.5
-1.0
-0.5
0.0
0.5
1.0
posi
tion*
( m
)
time (sec)
vertical horizontal
*scaling 'calibration' error possibly ~10%
30740 30760 30780 30800 30820 30840 30860 30880 30900 30920 30940
-0.15
-0.10
-0.05
0.00
*scaling 'calibration' error possibly ~10%
180x time zoom
horiz position
po
sitio
n (m
)
time (sec)
residuals sd 0.0151m over 145 points/240secs
σ =13.3nm rms
30740 30760 30780 30800 30820 30840 30860 30880 30900 30920 30940-1.30
-1.25
-1.20
-1.15
-1.10
*scaling 'calibration' error possibly ~10%
180x time zoom
A
residuals sd 0.0204m over 100 points/166secs (section A->B)
vert position
posi
tion
(m
)
time (sec)
B
σ= 20.4nm rms
2010 data, 4x109ph/sec at 7.2keV (K-B optic) :14(18)nm vertical(horizontal), 1sec33(48)nm 0,1 sec
21CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
analog stage: SAW tuned filter (500MHz for Doris-DESY tests); crossbar RF switch removes channel drifts
narrowband RF readout: i-Tech Libera
1234
beam X, Y, Σ out
over network
pulse signals in
synchrotron circulating e- beam position noise for Libera input signal attenuators 0-28dBresolution / stability 25ppm at 10khz if sufficient signal power
Guenther RehmDiamond Light Source measurements, 2008
10kH
z BW
noi
se (n
m)
beam current (mA)
22CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Bias
Four quadrant Single Crystal Diamond Sensor
RF Signal Impendence Matching Circuit
LiberaBPM Electronics
X-ray Beam
Sample
Control System
Modified Brilliance: new +12dB input low noise preamps after crossbar switch
E6 SC diamond in ceramic. 389µm thick, 50µm isolation cross, 3mm hole under the diamond for beam passage. ~100nm TiW contacts, Kagan, OSU
RF readout: Desy Doris synchrotron tests
23CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
B
C
scan-map results, Libera readout
Microscope image of mapped region on the scCVD diamond detector.
Corresponding Libera response map (sum of the normalized signals from electrodes B,C )20µm step spiral scan
-17.4 -17.2 -17.0 -16.8 -16.6 -16.4 -16.2 -16.0
9.6
9.8
10.0
10.2
10.4
10.6
10.8
X position (mm)
Y p
ositi
on (m
m)
010.0020.0030.0040.0050.0060.0070.0080.0090.00100.0
C
B
-17.4 -17.2 -17.0 -16.8 -16.6 -16.4 -16.2 -16.0
9.6
9.8
10.0
10.2
10.4
10.6
10.8
X position (mm)
Y p
ositi
on (m
m)
85.0087.0089.0091.0093.0095.0097.0099.00100.0
10 µm
-17.5-17.0-16.5-16.0
10.0
10.5
11.0
11.50
50000
100000
150000
200000
Y
X
-16.76-16.74
-16.72-16.70
-16.68-16.66
-16.64
3.00E+008
4.00E+008
5.00E+008
6.00E+008
7.00E+008
8.00E+008
10.14
10.1610.18
10.2010.22
10.2410.26
Res
pons
e
Y
X
550V bias, 2um steps (beam 20x20µm2 !)
24CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Effect of detector bias (390µm thick sample, 50µm isolation gap
550V
217V
138V
line scans with Libera RF readout
Diamond current pulse contains broad spectrum of frequencies,but Libera bandpass is ~5MHz at 500MHz
only a fraction of the signal currents contributes to rms signal power measured by Libera
carrier velocities not saturated at these low fields
-500 -400 -300 -200 -100 0 100 200 300 400 500
0.1
1
10
100
1000
sample S361-1(390um thick, TiW electrodes)
beam on other quadrants(signal from beam halo?)
curr
ent q
uad
2
(mod
ulus
nA
)
bias (volts)
V scanned at 4V/sec
beam on quadrant 2
beam off leakageceramic package 17pA at +350V
?? but for same device with Keithley 485 electrometer (100msec integration), response saturated for bias >100V
25CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Libera position ‘noise’ results
Measured <50nm rms resolution for 20Hz BW
Limit? Sensor-system noise shown here is convoluted with the real beam position noise!!
0 20 40 60 80 1000.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Vertical Horizontal
Sta
ndar
d D
evia
tion
m
bandwidth (Hz)
trace3.opj
FFT
26CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Conclusions / status:
CVD crystal quality (‘bundles’ or high density areas of threading dislocations) remain a major concern for device yield high leakage currents, signal hot spots ( and reduced CCE ?)No crystal quality progress seen for e6 ‘detector grade’ samples…
still a big problem for device yield
‘Proof of principle’ now established for intensity and position measurements of (monochromatic) synchrotron beams, using quadrant devices with both electrometer and RF readout techniques.Interest in application of diamond beam monitors at synchrotrons and now XFELs increasing: tests on ‘white beam, high thermal power response’ now also in progress at BNL…
to obtain stable blocking contacts, sub-surface damage of crystal from abrasive polishing must be eliminated, and ‘crap’ under contacts controlled
27CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010 27
Diamond devices developed atBrookhaven National Laboratory*
John Smedley1, Jen Bohon2, Erik Muller3, Jeffrey W. Keister4
1 Instrumentation Division, Brookhaven National Laboratory, Upton, NY 11973
2 Center for Synchrotron Biosciences, Case Western Reserve University, Upton, NY 11973
3 Stony Brook University, Stony Brook, NY 11794.
4 NSLS-II, Brookhaven National Laboratory, Upton, NY 11973
*slides by permission of John Smedley and Jeff Keister,
[highlight results, edited by JM]
28CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
•Linear over 12 orders of magnitude
Linearity at high currents, Pt electrodes (measurements in BNL NSLS-X28C X-ray beam, up to 20 W/mm2)
J. Bohon, E. Muller, J. Smedley, J. Synch. Rad 17, (2010)
1.E-08
1.E-07
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E-07 1.E-05 1.E-03 1.E-01 1.E+01
Power Absorbed by Diamond (W)
Gas ion chamber calibration
Calorimetric calibration
Fit, w = 13.4 +/- 0.2 eV
White / pink beam at up to 20 W/mm2
NSLS-X28C
Dia
mo
nd
sig
nal
(A
mp
s)
29CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Thermal Annealing
Shadow from sample holder
Before thermal annealing, blocking contact over entire metalized region for both polarities
After 600°C anneal, ‘photoconduction’ defect(s) observed, bias polarity dependent
30nm Pt contacts on O-terminated e6 sample, DDL(?) abraded diamond surfaceresponse to X-ray beam mapping
30CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
Localized PC hotspots, correlation with topography
‘Electronic Impact of Inclusions in Diamond’Erik M. Muller, John Smedley, Balaji Raghothamachar, Mengjia Gaowei, Jeffrey W. Keister, Ilan Ben-Zvi, Michael Dudley, and Qiong WuMater. Res. Soc. Symp. Proc. 1203-J17-19.DOI: 10.1557/PROC-1203-J17-19
31CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
4.5 mm Al beam attenuator
High/low photocurrent operation
30 nm Pt contacts
0.25 mm Al beam attenuator
PC gain for negative bias
PC gain removed by operating at low duty cycle
Full Beam
10% Duty
50% Duty
32CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
position noise data BNL-NSLS
RMS ~ 38 nm
RMS ~ 50 nm
Representative position calibration and noise data, RMS position noise (current mode) for ~40x40 µm2 white beam size (~100 mW/mm2). Pt contacts (BNL)
33CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
-100
-50
0
50
100
Y P
osi
tio
n (
µm
)
-100 0 100X Position (µm)
-100
-50
0
50
100
X P
osi
tio
n (
µm
)
50403020100
Time (ks)
x= 21 µm
50
40
30
20
10
0
Cu
rren
t (m
A)
1.6751.650Time (µs)
Charge = 0.17nC
Ring Structure at APS 11-ID-D• Ring mode “hybrid fill, top up”.• Tracked the singlet bunch position every
11 turns (40 µs) for 15 hrs• singlet bunch generates a peak current
density of 200 A/cm2
Position Stability at 11-ID-D, APS Argonne
34CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
X25 White Beam Position Monitor
Installed 13.6 m from MGU at X25For Large (6x1 mm2) beam at up to 100 W (20 W/mm2)Two diamond plates 100µm thick, tiled side-by-side
IN PROGRESS
Up to 700 mA expected (300 mA seen so far)Position noise estimate:~0.5 x 0.05 um resolution
‘Flux linearity demonstrated for up to 11W incident beam power, no limit yet found’
35CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010
end