1 CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010 1 5 Commissariat à l'Energie Atomique et aux Energies Alternatives, Gif-sur-Yvette, 91191, France 6

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)


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


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…


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


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


• 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


~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


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


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


e6 CVD sample variability (2009, samples supplied via DDL)

4x10-5

8x10-5

Δn

white is ‘off scale’

Light propogation along [100]


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


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


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)


-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


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


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!!


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


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


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


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


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


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)


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


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 !)


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


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


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]


•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)


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


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


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


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)


-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


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’


end

Documents

1 CARAT 2nd workshop, GSI Darmstadt 13-15 Dec 2010 1 5 Commissariat à l'Energie Atomique et aux Energies Alternatives, Gif-sur-Yvette, 91191, France 6