In-kind detector activity @ HZG
for the ESS detector group
(plans and detector capabilities)
G. Nowak1, M. Störmer1, C. Horstmann1, H.-W. Becker2, R. Kampmann3 M. Haese1,
J.-F. Moulin1, M. Pomm1, T. Kühl3, E. Prätzel3, D. Höche1,
I. Stefanescu4, J. Plewka1, C. Jacobsen1, J. Burmester1, R. Hall-Wilton4, M. Müller1
and A. Schreyer4
1Helmholtz-Zentrum
Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht, Germany
Bochum, RUBION, Universitätsstr. 150, 44801 Bochum , Germany
3DENEX – Detectors for Neutrons – GmbH, Stöteroggestr. 71, 21339 Lüneburg, Germany
4European Spallation Source ESS AB, P.O. Box 176, SE-221 00 Lund, Sweden
2Ruhr-Universität
IKON 10, 2016, 18th February, Düsseldorf
1
Outline
• short intro: 10B4C coating based neutron detectors
• Results from previous projects
• Milestones for the proposed project (Am-CLD)
• Summary
2
Gaseous MWPC driven by 10B4C
neutron converter and delay-line
y
stopping-gas
n
I-pulse
A
detection/
kV
measurement
x
anode (MW)
Θin= 1°- 90°
y
y-cathode (MW)
++ --α
rα
r7Li
2D- intensity map
10B C-converter
4
x-cathode (MW)
1 µm
substrate
neutron!
n + 10B → 7Li + α + (γ)
x
i)
penetration length in 10B before absorption/capture for thermal –
cold neutrons: 32 µm - 12 µm
ii) ion range for α-particle: 3.2-3.9 µm and for 7Li particle: 1.5 – 1.7 µm in 10B4C +,++
+
J. P. Biersack and L. Haggmark, Nucl. Instr. and Meth. 174, 257, (1980)
F. Ziegler, J. P. Biersack and U. Littmark,”The Stopping and Range of Ions in Solids”, Pergamon Press, New York, (1985)
++J.
iii) ion range for α-particle: 2-3 mm and for 7Li particle: 1 – 1.5 mm in 1 bar CF4
3
A1- and Am-CLD detector concept:
neutron incidence geometries
A1-CLD ( Absorption in 1 Layer Conversion Detector):
n
Θin = 2°
• high conversion efficiency (++)
• position resolution: sub-mm! (++)
• fixed detector-sample distance (o)
stopping gas
converter
1 µm 10B4C
10B
good for SANS, HR-diffraction, (well
collimated beam)
abs. length: 32 µm - 12 µm
ion range: 3.9-1.5 µm
Am-CLD ( Absorption in multiple Conversion Detector):
1 µm 10B4C (2x converter per det. plane)
stopping gas
stopping gas
stopping gas
stopping gas
• position resolution: wire pitch mm (+)
• variable detector-sample distance (++)
• variable converter layer thickness (++)*
n
converter
converter
Θin = 90°
…
…
x6 - 15
good for diffraction, SANS, beam monitor
*F. Piscitelli and P. Van Esch JINST 8, P04020, 2013
4
10B
4C-conversion
coatings
5
10B
4C
neutron conversion coatings
(European Patent Application WO2016/008713
patent pending 21.01.2016)
1.2 µm 10B4C coatings on 0.3 mm Al:
HZG sputtering facility:
1m
(100 mm x 1430 mm)
(300 mm)
coating characteristics:
-
amorphous, highly adhesive, almost lit. density
-
highly flexible converters
-
Hydrogen content: below 0.3 %
-
High neutron efficency
B4 C
Si
- G. Nowak, M. Störmer, H.-W. Becker, C. Horstmann, R. Kampmann, D. Höche, M. Haese-Seiller, J. - F. Moulin, M. Pomm, C. Randau, U. Lorenz, R. Hall-Wilton, M. Müller,
A. Schreyer, J. Appl. Phys., 117, 034901 (2015)
6
Advanced research on Boron carbide
coatings process @ HZG
1.2 µm 10B4C coatings on 0.3 mm Al:
HZG sputtering facility:
1m
(100 mm x 1430 mm)
(300 mm)
coating characteristics:
-
-
highly uniform on 100 mm x1500
mm < 4 %
application also for X-ray
mirrors at sync. sources w-w.
y (mm)
120
content of residual gases (O, N,
Ar,…) < 2%
+4 %
0%
60
-4 %
0
-
Thickness uniformity on 1500 mm x 120 mm:
375
750
x (mm)
1000
1500
-M. Störmer, F. Siewert and H. Sinn, J. Synchrotron Rad., 23, 50-58 (2016)
7
Performance of A1- and Am-CLD
8
Inside view in the A1- and Am-CLD
prototype detectors (200 mm)
A1-CLD detector inside:
Am-CLD detector inside:
DENEX
y-cathode
anode
x-cathode
10B C-Al-plate
4
support
one partial detector plane (about 9 mm!)
Rel. quantum efficiency of 1 µm
10B C in the A1-CLD detector
4
12000
Ɵ
P1; 1 µm 10B4C,  = 4°
8000
TESTDETECTOR
6000
4000
quantum efficiency
ct in 1800 s
10000
2000
0
ct in 600 s
2
3x
Ɵ
Ɵ == 2°
1°
4°
n
P1; 1 µm 10B4C,  = 1°
P1; 1 µm 10B4C,  = 2°
4
6
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
Qeff.
8 10 12 14 16 18 20 22 24
(Å)
3
1,0
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0,0
He-10bar, 1'-counter
MONITOR
P1, 1µm 10B4C,  = 1°
P1, 1µm 10B4C,  = 2°
P1, 1µm 10B4C,  = 4°
2
2
4
6
8 10 12 14 16 18 20 22 24
(Å)
3
4
5
6 7
(Å)
8
9
10 11 12
Θ = 2° is a good compromise eff.tech. feasibility
rel. Qeff. of up to 85 % of a 3He counter tube
measured @ REFSANS (MLZ)!
10
Position detection by the
A1-CLD detector
Z
n
Ɵ =4°
Y
measured @ REFSANS (MLZ)!
11
DENEX
ch= 5 => 0.2 mm!
105
z-pos: 2.9 z=2.9
mm
Gauss-Fit
z=2.9
Gauss-Fit
z-pos: 3.1 z=3.1
mm
z-pos: 3.1 mm
Gauss-Fit z=3.1
104
inter. int.
beam size:
0.3 mm x 20 mm
detector shift:0.2 mm
High position precision of
the A1-CLD detector concept
103
102
20 mm
101
210
240
270
300
330
360
z-channelNr
z-chanal (-)
 position resolution < 0.1 mm
for direction parallel to the converter plane normal!
12
Position resolution of the
Am-CLD detector concept
plane 6
6 detection planes in operation at
REFSANS@MLZ!
plane 5
plane 4
plane 3
plane 2
30°
n
1
2
3
4
5
6
plane 1
13
Position resolution of the
Am-CLD detector concept
DENEX
20 mm
plane 6
4 mm
Position resolution < 4 mm
14
Milestones for the proposed project
(Am-CLD)
15
Am-CLD demonstrator detector
for Diffraction (500 mm x 700 mm)
-Large housing allows for stepwise growing of the Am-detector to the final stage.
Stage 1: (2015-2017)
• 30 x (100 mm x 700 mm) converter 1.2 µm 10B4C
• Am-CLD with 3 detection planes (500 x 700)
• tests at HZB, Rez with neutrons:
Electronics
Challenges:
1) mech. support of converter planes
2) minimize dead zones between
converters
3) minimization of detection plane
depth (T resolution, parallaxe eff.,
housing Vol.)
4) read-out: electronics, software
5) Background
Detector
700 mm
500 mm
16
Electrode set up of Am-CLD
Multiwireanode (y)
Multiwirecathode (x)
2x B4C coated Al-plate
(drift electrode) (back-to-back)
B4C coated Al-plate
(drift electrode)
one detection plane
window
neutrons
Udrift UAnode UAnodeUdrift
UAnode
17
Position Encoding by delay line:
chopper start (ToF-mode)
output (x0)
of x-cathode
output (x1)
of x-cathode
1 X,R,stop
X,L,stop
output (R)
IV110
of anode
tr = 1.0 ns
nf = 1.6 db
Z = 50Ω ± 20%
Delay
[ns]
Z
[Ω]
1
50
2
50
3
50
output (L)
of anode
IV118
tr = 1.2 ns
nf = 0.4 db
Z = 50Ω ± 20%
(no coils!)
C
[pF]
L
[nH]
=> chopper signal starts the TDC!
20
50
Delay
Z
T1
(x-cathode)
–
t
(chopper)
=
[ns]
[Ω] tx
X(L,R,stop)
start
40
100
2.17
T2
(y-anode) – tstart(chopper)
= t46y
60 y(L,R,stop)
150
|T1X,L +T1X,R - TDL| < εDL
C
[pF]
L
[nH]
47
100
1.97
51
39
100
1.82
55
33
100
=> (tx,ty) =(nx*2 [ns],ny*2 [ns])=> vG*(tx,ty)=(x,y)neutron
18
Software TDC read out on FPGA
Main FPGA
Acquisition
control
start
1. FPGA
stop-signals
…
(x,y,z,I,t)
6. FPGA
start
stop-signals
chopper-start
X1
Neutron
X1
Y1
Neutron
X1
Y1
Y1
Neutron
ToF
…
Chopper
Y0
Y0
1. Detectorplane
Y0
2. Detectorplane
X0
n. Detectorplane
X0
- robust, modular and universal design (malfunction,…)
- high position resolution/efficiency
X0
up to 12 planes
19
Performance of envisaged TDC
read-out schema
•
•
•
[4(EL)x3(PL)]x2(CFD+ToT)+1(Ch.) TDCs (in time sampling mode) written
on two FPGA (for 3 detection planes)
96 + x time channels should detect 20-30 ns wide falling
and 30-40 ns wide rising edges of n-pulses (12 planes Am-CLD)
Time stamps per plane for one event:
[4 (x,y) + max.1 (ch.)] x2(f/r) x2 (ToT.)=
max. 20 stamps in max. 64 bit string
•
4(EL)x2(ED)x2(CFD+ToT)x(Nr.PL)x(8Byte):
=> Data rate: < 128 Byte x event rate = data stream per plane
•
max. Data rate at max. count rate (170 kHz per plane!):
a) 3 planes: about 65 MB/s
b) 12 planes: about 261 MB/s
more at poster: “Readout-Electronics for Delay-Line Detectors with 10B4C Converters”
C. Jacobsen: Entwicklung einer Multikanal-Auswertehardware für Delayline-Neutronendetektoren; Masterarbeit am HZG-TKE, in Betreuung
durch Fachhochschule Westküste und Hochschule für Angewandte Wissenschaften Hamburg, wird vorgelegt am 29.02.2016
20
Expected performance for
Am-CLD (3 planes)
-ToF-Timing resolution:1 µs (limit geo.) - 1ns (limit ele.) (spectrospy, spin echo)
- Position resolution: 2 mm x 5 mm
- Rate capability: ave. 170 kHz per plane => global: 3 x 170 kHz => (12 planes): 2 MHz
- Data stream at highest rate: 65MB/s (3 planes); 261 MB/s (12 planes)
- Efficiency: 10 – 36 % at 1- 5 Å
Geant4 simulations provided by Dr. I. Stefanescu (ESS-DG)
21
Am-CLD demonstrator detector
for Diffraction (500 mm x 700 mm)
Stage 2: (after 2017)
• 150 x (100 mm x 700 mm) converter
• Am-CLD with 12 detection planes
(500 x 700)
• tests at HZB/REZ/ESS with neutrons:
1) amount of coatings Link.HZG
2) read-out: electronics, software
3) thicknessprofil
4) Background
x 12
planes
700 mm
500 mm
Geant4 simulations provided by Dr. I. Stefanescu (ESS-DG)
22
Time line of the Am/A1-CLD
x/2016 – x+2/2016: coating of the unfinished 8x(500 mm x 700 mm) and
31x(100 mm x 200 mm) converter elements
x/2016 – x+3/2016: Coating tests in high neutron flux
x/2016 – x+3/2016: Development/fabrication of trigger board/s
x/2016 – x+4/2016: programming of TDC read–out on FPGA for one 2D-plane
x/2016 – x+3/2016: fabrication of housing and first partial detector
(500 mm x 700 mm)
x/2016 – x+2/2016: pre-characterization, Neutron tests at beamlines (also A1), data eva.
x/2017 – x+4/2017: programming of TDC read–out on FPGA for x-2D-plane
x/2017 – x+4/2017: fabrication additional x-2D-planes in the detector housing
x/2017 – x+5/2017: pre-characterization, Neutron tests at beamlines (also A1), data eva.
x/2017 – x+2/2017: reports, publication
23
Summary
• well performing A1 and Am-CLD presented
• High quality coating process on large size substrates is manifested
(papers, patent pending)
• proposed future activity established on solid, results.
• mechanical engineering challenges in the up-scaling of the detector present.
• Size and position resolution of proposed Am-CLD detector meets request of
diffraction beamlines @ ESS
• envisaged TDC read-out schema copes for 2 MHz global count rate at an
high detection efficiency and at a moderate data stream.
• The read-out hardware is for A1-CLD and Am-CLD identic. “One for all”
24
Thank you for your attention!
25