Transcript Position sensitive scintillation detectors for trigger

Position sensitive scintillation
detectors for the trigger system in
the space experiment NUCLEON
Supervisors: Anatoliy I. Kalinin a
Students:
Irina Cioara b
Alexandra Chilug b
a
Joint Institute for Nuclear Research, Dubna,Russia
b University of Bucharest, Romania
Dzhelepov Laboratory of Nuclear Problems
Cosmic rays
Were discovered by Victor Hess in 1912

They are energetic charged subatomic
particles, originating from outer space. They
may produce secondary particles that
penetrate the Earth's atmosphere and surface.

The NUCLEON experiment is aimed at
studying cosmic rays that have energies
between 1011- 1014 eV.

The TUS experiment is aimed at studying
cosmic rays that have ultra high energy,
above 5*1019 eV. The used method is an
indirect one, that does not remember the
primary particle.
NUCLEON

The main idea of the NUCLEON project is to
design and to create a scientific device with large
aperture and a relatively light weight for measure
elemental spectra of cosmic rays in a wide energy
range E ~ 1011- 1014 eV.

The method is based on event by event
measurement of spatial distribution of the
charged and neutral secondary particles which
were produced in the inelastic nuclear interaction
in the target of the detector and have passed
through layers of silicon micro strip detectors and
thin converters to produce e- e+ pairs of the
secondary gammas. This technique is known as
KLEM (Kinematic Lightweight Energy Meter).
KLEM
[Kinematic Lightweight Energy Meter]

The main objective of the KLEM instrument is direct
measurement of the elemental energy spectra of high-energy
(1011-1016eV ) cosmic ray in space.

The basis of the KLEM method is energy determination by
measuring the number and the angular distribution of
secondary particles produced in a target.

The energy of a primary particle is calculated using the
following function:
S ( E)   Ni i2
i
Ni= number of secondary particles registered in strip i
ηi= pseudorapidity
i  Ln(tan(xi / 2h))
xi= distance of strip i from the point of intersection of the
extrapolated primary particle trajectory with the detector plane
h= the distance between the detector plane and the midle of the
target
KLEM
Advantages of KLEM method:

a large aperture

a lightweight device (it does not need a
thick absorber)

has easy read out of information (thanks
to the use of silicon microstrip detectors)

long duration exposures in orbit

measurement of an individual energy
spectra with single technique over a very
wide energy range
NUCLEON Structure
Trigger system
The goal of the trigger system is the selection and rejection of data flux to a limited volume that can be
transferred to the ground data acquisition and control center for further offline analysis.
COMPARATOR
P-16
P-32
MPMT
X
Fibers
P
1
PMT+
IVN
A
PMT
+ IVN
A
P-16
MPMT
Y
PMT
+ IVN
PMT
+ IVN
Block diagram of the plane
P
1
A
A
•
Scintillator detectors - basic instruments for registration of cosmic rays and other radiations.
Amplifier
PMT
A
CC
COMPARATOR
Fiber
Scintillator
The scintillator converts the falling radiation into a short pulse of visible light.
The photomultiplier converts the collected light from the scintillator into electrical signal and amplifies
it as much as possible.
In the NUCLEON project vacuum photomultipliers are used.
PMT and SiPM
Silicon PhotoMultiplier
Vacuum Photomultiplier
Spectrum of Light Diod
SiPM
2000
S60
E= 60V
430nm
S= 6,6V
1800
1600
D19600
1400
1200
N
1000
800
600
400
200
0
-200
0
500
Channels
1000
1500
2000
N
The general equivalent circuit of the SiPM
Advantages for Silicon Photomultipliers:
 Applicability in many different fields (high energy physics calorimetry, astrophysics, medical
imaging)
 Low voltage supply (<100 V)
 Insensitivity to magnetic field
 High gain ~ 106
 Better one-electron resolution
Thank you for your
attention!