Dipartimento di Astronomia e Scienza dello Spazio

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Applications of fast mid-IR detectors as beam
monitor in the sub-ns time domain
Alessio Bocci

• Dipartimento di Astronomia e Scienza dello Spazio
  
• (Università di Firenze)
• Laboratori Nazionali di Frascati (INFN)

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OUTLINE

• FAR FIELD BEAM DIAGNOSTICS
• Fast vs. VERY Fast INFRARED DETECTORS
• TEST AT DAFNE
• FUTURE APPLICATIONS

Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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BEAM DIAGNOSTICS WITH SR
DIMENSIONS OF CROSS SECTION OF THE BEAM BY THE
IMAGE OF SR EMISSION
MEASURE OF THE ANGULAR SPREAD OF THE PARTICLES
IN THE BEAM BY OBSERVATION OF THE DIRECT
EMISSION
BUNCH LENTGHS few mm few ps NEED OF FAST
PHOTON DETECTORS!
A. Hofmann Beam Diagnostics and Applications
BIW 98, Stanford
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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STATUS OF THE ART OF SR BEAM DIAGNOSTICS
XBPMs
MEASURE OF SR INTENSITY
FROM IMAGING OF SR EMISSION BEAM PROFILE, BEAM
POSITION BEAM STABILITY AND DYNAMICS CAN BE
OBTAINED
SR MONITORS VUV, X-RAY AND VISIBLE WAVELENTHGS
DETECTORS CCD /Si ARRAY/ PHOTODIODES
K.Holldack, BESSY
MEASURE OF TIME RESOLVED SR INTENSITY
FAST PHOTON DETECTORS BUNCH LENGTH
MEASURAMENTS Sub-ns to ps response time
VERY FAST IR UNCOOLED OR PELTIER
COOLED PHOTODETECTORS
POSSIBILITY TO ASSEMBLE PHOTODETECTORS AS 1D OR
2D ARRAYS FOR IMAGING WITH SUB-ns TIME RESOLUTION
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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IR RADIATION AND PHOTON IR DETECTORS
Quantum detectors fabricated with narrow-gap
Semiconductors (intrinsic or extrinsic)
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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PHOTO DETECTORS RESPONSE TIME
Response time t
Time for the detector output to fall to 1/e of
the initial value when radiation is switched off
How fast a photo detector can respond to a pulse
of optical radiation depends to
Carrier lifetimes in semiconductors (majority or
minority carriers) Recombination time of
carriers inside the semiconductor Diffusion,
drift and trapping of carriers inside the
semiconductor Transit time of photo generated
carriers RC constant of equivalent circuit
D(AoDf)1/2/NEP
D can be interpreted as S/N ratio out of a
detector normalized to the detector area and
bandwidth
In Photo-conductive detectors
D t 1/ 2
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IR-BEAMLINE AT FRASCATI-INFN
BRILLIANCE IRSR SINBAD
e e- collider Low Energy E0.51 GeV High
Current I gt 2 A
Spectroscopy and Micro-Spectroscopy Experiments De
velopment of fast IR detectors
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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TEMPORAL STRUCTURE OF ELECTRON BUNCHES AT DAFNE
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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SIGNAL OF THE RADIATION EMITTED BY THE 105
ELECTRON BUNCHES
V
6.5mV
Bunches 280 5 ns
Gap 40 5 ns
HgCd(Zn)Te uncooled IR detector t 1ns ?
optimized _at_ 10.6 micron
Voltage AMP 500 MHz Bandwidth
SCOPE
SR
Alessio Bocci,Univ.Firenze,LNF-INFN
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SIGNAL OF ELECTRON BUNCHES WITH A SPECIFIC
BUNCHES FILLING SCHEME
Alessio Bocci et al. LNF - 05 / 12 (NT)
Signal of IR emission of the electon bunches of
DAFNE
V
Best measurement 8 ns or 125 MHz (RF/3)
13.5 ns
Response time of detector 3.5ns
11 ns
Red Boxes Filled Bunches White Boxes Empty
Bunches
t
http//www.lnf.infn.it/sis/preprint
Alessio Bocci,Univ.Firenze, LNF-INFN
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IMPROVMENTS IN THE MEASUREMENT
Most of the incident radiation on the detector
has wavelength shorter than those optimized for
the detector. As a consequence an increase of the
response time is expected. The absorption of
short (llt lmax/2) wavelength radiation in PVM
and some other detectors backside illuminated
occurs at large distance from the junction plane.
Therefore, the time necessary to photogenerated
carriers to travel towards the junction is long.
BACKSIDE-ILLUMINATED
NEW PHOTOCONDUCTIVE DETECTOR FRONT-SIDE ILLUMINATE
D WILL BE TESTED
RESPONSE TIME 500ps
SUITABLE TO OBSERVE THE DISTANCE BEETWEEN TWO
BUNCHES AND TO OBSERVE THE RISE TIME OF EACH BUNCH
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IR DETECTORS SEMICONDUCTORS
High a/G (D a/G) High QE Large tunable gap l
cut-off 1-25 micron (also dual band or
multicolor detector) Working also at higher
temperature
HgCdTe is the most important semiconductor
alloy for Near-Mid-IR photon detection
Why?
D for thermal noise limited HgCdTe photodetectors
BLIP Background photon noise
77 K BLIP PERFORMANCE beetwen 2-20 micron
230 K (Peltier coolers) Sub-BLIP for MWIR and LWIR
300 K MWIR Sub-BLIP LWIR Two or more order of
magnitude below BLIP performance
J.Piotrowski, 2nd Cephona Workshop, Warsaw, 2004
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FAST UNCOOLED AND TE-COOLEDIR DETECTORS
AMBIENT AND PELTIER-COOLED IR HgCdTe
PHOTODETECTORS
D IS LIMITED BUT SUITABLE FOR THE DETECTION OF
BRILLANT RADIATION SOURCES as STORAGE RINGS
(DAFNE) or FEL
ADVANTAGES
VERY FAST DETECTORS SMALL SIZES
DETECTORS!!! COST-EFFECTIVE DETECTORS!!! NO
NEED OF COOLING SYSTEM OR, AT LEAST ONLY SMALL,
LONG-LIFE, LOW POWER AND LOW COST COOLERS
VACUUM COMPATIBLE
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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FAST UNCOOLED AND TE-COOLEDIR DETECTORS
AMBIENT AND PELTIER-COOLED IR HgCdTe
PHOTODETECTORS
D IS LIMITED BUT SUITABLE FOR THE DETECTION OF
BRILLANT RADIATION SOURCES as STORAGE RINGS
(DAFNE) or FEL
NO FUNDAMENTAL PROBLEMS LIMIT THE DETECTION OF
MWIR AND LWIR RADIATION WITHOUT CRYOGENIC
COOLING ONLY TECHNOLOGICAL PROBLEMS THAT CAN BE
SOLVED AFFECT THE DETECTION
THESE DEVICES CAN BE REALLY FAST! ps response time
J.Piotrowski, 2nd Cephona Workshop, Warsaw, 2004
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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IR PHOTODETECTORS
MAIN PRINCIPLES OF GENERATION OF
OPTICALLY CARRIERS IN PHOTODETECTORS
PHOTOCONDUCTIVE PC detectors PHOTOELECROMAG
NETIC PEM detectors PHOTOVOLTAIC PV detector
s
ELECTRICALLY BIASED DEVICES SIGNAL GENERATED IN
THE ABSORBER BY CHANGE OF ITS RESISTENCE
OR CONDUCTANCE
SIGNAL GENERATED BY DIFFUSION OF PHOTOGENERATED
CARRIERS DEFLECTED BY A MAGNETIC FIELD (2T,
PERMANENT MAGNETS)
PHOTOVOLTAIC EFFECT IN BIAS OR UNBIASED HOMO OR
HETEROJUNCTION
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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PHOTOCONDUCTIVE DETECTORS
J. PIOTROWSKI, OPTO-ELECTRONICS REVIEW 12(1),
111122 (2004)
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PHOTOELECTROMAGNETIC DETECTORS
mm
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PHOTOVOLTAIC DETECTORS
mm
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STACKED MULTIJUNCTION PHOTODIODE DETECTORS
POTENTIAL TO ASSEMBLE IN 2D VERY LARGE (106)
ARRAY DETECTORS LIMITED ONLY BY ACTUAL TECHNOLOGY
RESPONSE TIME LIMITED BY RC TIME CONSTANT
t lt 20 ps
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COLLABORATION WITH Prof. JOZEF PIOTROWSKI (Chief
Scientist VIGO SYSTEM S.A. COMPANY)
MOCVD SYSTEM _at_ VIGO
MOCVD METALLORGANIC CHEMICAL VAPOUR
DEPOSITION Epitaxial growth of multilayer
heterostructures of Hg1-xCdxTe on GaAs, Si,
sapphire SUBSTRATES
Collaboration with Univ. Firenze and LNF-INFN
to develop, optimize and test fast uncooled and
Peltier cooled IR detectors for high frequeny
applications (?opt.2-14 micron) Few picosecond
response time
A.PIOTROWSKI et al., OPTO-ELECTRONICS REVIEW
12(4) (2004)
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DIAGNOSTICS
.....
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Response time 1/2p Bandwidth
STACKED MULTIJUNCTION PHOTODIODE DETECTORS
t 4 ps
t 17 ps

• lt20 ps

(J.Piotrowski communication)
DIAGNOSTICS
.....
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Projects at DASS-UNIV.FIRENZE and at LNF-INFN

• DEVELOPMENT OF FAST IR UNCOOLED
• BILINEAR-ARRAY DETECTOR
• 2X32 PIXELS
• FOR IR BEAM DIAGNOSTICS AT DAFNE
• RESPONSE TIME OF EACH PIXEL 500 ps
• (few weeks)

Pixel size 50x50 micron
Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
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Projects at DASS-UNIV.FIRENZE and at LNF-INFN

• MOUNTING ON BOARD AND WIRE BONDING OF THE ARRAY
• AT A CLEAN ROOM

2) DEVELOPMENT OF READOUT ELECTRONICS AND FAST
AMPLIFIERS FOR EACH SINGLE CHANNEL
COMPUTER and SOFTWARE
ELECTONIC BOARD AMPLIFIER and ADC
64 FAST PREAMP
3) FAST UNCOOLED OR PELTIER COOLED IR DETECTORS
OPTIMIZED FOR TIME RESOLVED SPECTROSCOPY
(RESPONSE TIME ns)
Alessio Bocci,Univ.Firenze, LNF-INFN
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CONCLUSIONS

• DAFNE IS AN OPTIMIZED SOURCE FOR IRSR EMISSION
• FLEXIBLE TIME STRUCTURE FOR FAST AND VERY FAST
  DETECTORS EXPERIMENTS
• UNCOOLED IR DETECTOR TECHNOLOGY IS MATURE FOR
  BEAM DIAGNOSTICS
• RD OF UNCOOLED ARRAY DETECTOR FOR IMAGING WITH
  VERY SHORT RESOLUTION TIME IS IN PROGRESS
• POTENTIAL APPLICATIONS TO SPECTROSCOPY AND
  DIAGNOSTIC IN MANY SR FAILITIES

Alessio Bocci,Univ.Firenze, LNF-INFN
ICFA, LNF-Nov.2005
26
Acknowledgments
Augusto Marcelli LNF-INFN Alessandro
Drago LNF-INFN Emanuele Pace DASS
Università di Firenze Jozef Piotrowski
and VIGO S.A. his scientist group SINBAD IR
Group LNF-INFN Diego Sali, Pierangelo
Morini BRUKER Optics IMONT