Download RADIATION AND PARTICLE DETECTORS High Energy Physics

RADIATION AND PARTICLE DETECTORS
High Energy Physics Detectors
Applications
Measurement of X rays, gamma rays and cosmic
rays.
After having been slightly modified in lay-out and
read-out, they can also be applied to different
purposes: high energy physics experiences on
earth (silicon detectors, plastic scintillators, CsI
pixel arrays...), radiation monitoring (silicon
detectors), biomedical digital radiography (gas
microstrip detectors).
Gas scintillation proportional
counters;
This kind of instrument detects energy events
between 1 and 120 KeV; it has different and
peculiar
characteristics
depending
on
application fields.
It requires supplying and distribution systems
for high voltages (up to 30 KV) , which design
is made difficult by high level of
miniaturization and efficiency needed.
Phoswitch detectors;
This kind of instrument is made by coupling
photoscintillator layers of CsI and NaI.
They can detect gamma rays, Xrays and
particles within a range between a few
tensand many hundreds of KeV.
Peculiar
techniques
of
the
signal
discrimination have been developed from the
two responses of the detector materials,
exploiting the different scintillation time
constants between CsI and NaI.
Plastic scintillators;
Mainly utilized as an anticoincident shield for
X and Gamma detectors, in order to reduce
incident background on detecting surfaces.
These instruments must be accurately light
tightened and coupled with photomultiplyers
(PMT) (both straight or by optical fiber).
Involved PMT are chosen according to optical
characteristics of scintillator material:
choosing the coupling technology is mainly
important since optical coupling must survive
to environmental conditions and collect the
most possible light.
Collimators for X and Gamma rays;
They are composed of Ta/W and/or Pb/Al cell
assembling to limit the incident radiation field
of view.
Tilting such systems enables to discriminate
incident from background radiation.
Silicon detecting surfaces;
Designed to measure the energy and the path
of the incoming cosmic rays and particles.
Peculiar assembling procedures of silicon
detector on ceramic substate have been
developed in order to satisfy environmental
requirements (launch loads).
These procedures enable a high level
packaging of said detector with the relevant
front end electronics (FEE).
Pixel matrix calorimeter;
Each pixel in this instrument is an
independent detector and the matrix is
composed of hundreds of pixels assembled
as honeycomb structure.
Read-out electronics is made of photodiodes
coupled with single crystals and of related
electronic chains integrated within one or
more digital-analogic ASIC.
Using CsI crystals one can obtain minimum
energy theresolds ranging around 100 KeV
and reduced power consumptions.
Microstrip detectors for charged
particles;
An acting substrate made of a thin glass
layer, which eletrodes are printed on, enable
to reach a high spatial resolution (few
micrometers) and a time constant of few ns.
A composite structure
maintains the
substrate within a volume filled by an
appropriate gas mixture.
The assembling technology of the detector
appears to be critic: it must be performed
within a high-level-cleaned room by the aid of
non-polluting materials.
Heritage:
Sax_MECS (Medium Energy Concentrator
System)
Sax_HPGSPC
(High
Pressure
Gas
Scintillation Proportional Counter)
Sax_PDS (Phoswich Detector System)
Integral_IBIS (Pixit and Veto)
High Frequency Radiometers
Application
Measurement of microwave range in astronomic
observations .
Features
High Frequency Radiometers are based on low
noise HEMT amplifiers for radioastronomy
measurements.
Scientific Equipment Directorate has developed
technologies and products for Radiometers up to
100 GHz:
Radiometric chains cooled at 20 K for an
extremely fine survey of the cosmic
microwave background;
Feed horns, orthomode transducers, wave
guides;
Highly stable secondary power generation
modules;
This datasheet is not contractual and can be changed without any notice
For further information, please contact
Thales Alenia Space Italy
Via Saccomuro, 24
00131 ROMA - ITALY
Tel.: + 39(0)6 41511
Fax: + 39(0)6 4190675
Website : www.thalesaleniaspace.com
AGILE (Minicalorimeter)
Technologies:
Electrical Field Modeling
High Voltage Design
Feedthrough Brazing
PMT/ Photodiode Optical Coupling and
Packaging
Light Collection technology
Detector Characterization by means of
Radioactive source
Mechanical and thermal design of focal plane
for cryogenic applications
Data Acquisition Electronic for conditioning of
very weak signals, fast digital conversion with
extremely high resolution;
Scientific Data Management Software
Peculiar circuits and devices on Radiometers,
have been designed for the analogic acquisition of
sensor signals (pre-amp, formatters, peak
discriminator, multiplexer, trigger logic, ADC).
The digitalized signal is afterwards utilized within
complex algorythms for energy correction and
data reduction.
The front-end electronics are mainly adjusted to
match with sensor characteristics: physical
structure, signal-to-noise low ratio, dead time,
channel density.
FEE can as well be implemented by different
packaging technologies (SMT-boards, hybrids-orASIC components) according to varying
miniaturization requirements.
High voltage low noise power supplies have been
developed, working from tens of Volt up to tens of
Kvolts, designed by the aid of space qualified
technologies.
Technologies:
Electrical Field Modeling
High Voltage Design
Feedthrough Brazing
PMT/ Photodiode Optical Coupling and
Packaging
Light Collection technology
Detector Characterization by means of
Radioactive source
Updated :December 2006