4. Introduction:
Accelerators
“A particle accelerator is a device that
uses electromagnetic fields to propel
charged particles to high speed and to
contain them in well-defined beams.”
Detectors
“A device used to indicate the presence
of fast-moving charged atomic or
nuclear particles by observation of the
electrical disturbance created by a
particle as it passes through the device
known as radiation detector.”
5. Kinds of the detectors
Many of the detectors invented and used so
far for ionization detectors (of
which semiconductor detectors and gaseous
ionization detectors are most typical)
and scintillation detectors but other
completely different principles have also been
applied like Cerenkov detector and transition
radiation.
6. SEMICONDUCTOR DETECTOR.
In a semiconductor radiation detector, to
make hole-electron pairs, incident radiations
interact with detector material which is a
semiconductor material like Si or Ge. By the
help of charged electrodes hole electron pairs
are collected, so the electron are transfer to
positive electrode and holes to negative
electrode that creates an electrical pulse.
7.
8. Solid State Detector.
Definition:
“If an insulator crystal (diamond, Cadmium
Sulphide) is placed between two electrodes
placed at a large potential difference this
arrangement is known as solid state detector
which can be used as a high energy radiation
detector.”
Explanation:
In these insulators the valance band is completely
filled with electrons and the conduction band is
totally empty for a pure crystal. In between there
is a forbidden zone of width Eg of few electron
volts (in case of diamond Eg=5.2ev).
9. There are many types of solid state detectors
which are given as following
Diffused junction detector.
Surface barrier detectors.
Silicon-Lithium detectors.
Ge-Li detectors.
10.
11.
12. “An ionization chamber is a close vessel filled
with a suitable gas and having two
electrodes. The potential difference between
these two electrodes is few hundred to a few
thousand and the pressure of gas is of order
of one atmosphere or more.”
13.
14. EXPLANATION:
There are two type of geometry of ionization
chamber
Parallel plate geometry.
Cylindrical geometry.
There are two metallic plates separated by a
distance d. if the potential difference the
electrodes increases then positive and negative
ions are produced in the gas which moves in
the opposite electrodes. At low voltage the
velocity gained by the ions due to applied
electric voltage X=V/d is small. Hare d is
distance between electrodes and V is velocity
gain by ions.
15.
16. GEIGER-MULLER DETECTOR:
The Geiger–Müller tube (or G-M tube) is the sensing
element of the Geiger counter instrument used for
the detection of ionization radiation.
CONSTRACTION:
G-M counter consists of a cylindrical sealed glass
tube of radius 2 to 3 cm having metallic cylinder
C which behave as a cathode. A very thin metal
wire usually tungsten of diameter˷̰0.1mm acting
as anode. In this detector ,apply voltage between
anode and cathode. Tube is filled with inert gas
such as Argon which is mixed with the vapor of
Ethyl Alcohol (volatile compound) in the ratio of
10:1 having pressure
17.
18. PHOTOCONDUCTIVE DETECTOR:
“It is a special type of detector use in
measurements of short bursts of intense
radiation.”
CONSTRUCTION:
Photoconductive detector consists of a
sample of semiconducting material fitted with
two injected contacts or” Ohmic “contacts at
opposite surfaces.
19. WORKING:
When voltage is applied , a measureable current flows that is
determined by the free carrier concentrations in the
semiconducting material .We assumed that usually condition
applied in which only one carriers (usually electrons)
dominate the conductivity of the material. The carriers
concentration will be increased by irradiating the device the
device with a pulse (or continuous flux) of ionizing
radiations, resulting increase in conductivity of material.
20. Detectors used in Labs
4.1 LHC
The most powerful and world's largest
particle collider is Large Hadron Collider
(LHC) which was built by the CERN from 1998
to 2008. The main purpose of LHC is to allow
scientist to test the different theories relating
to the particle Physics and high-energy
Physics.
21.
22. 4.2 CMS
CMS stand for Compact Muon Solenoid. This
experiment is one general-purpose particle
detectors which are built on the Large
Hadron Collider (LHC) at CERN in Switzerland
and France. The purpose of this CMS
experiment is to investigate a wide range of
physics such as extra dimensions and those
particles which are made up dark matter
23.
24. ATLAS (A Toroidal LHC Apparatus)
Atlas Is one of the seven particle detector
experiments which are ALICE, ATLAS, CMS,
TOTEM, LHCb, LHCf and MOEDAL. These are
constructed at the Large Hadron Collider (LHC), a
particle accelerator at CERN which is situated in
Switzerland. (the European Organization for
Nuclear Research.
At SLAC
SLAC stand for Stanford Linear Accelerator Center
which is situated in United States. Department of
Energy National Laboratory is operated by
Stanford University under the direction of the
United States Department of Energy Office of
Science and it is located in California.
25. Drift Chamber
The drift chamber is the innermost sub-
detector of the BESIII detector. It is one of the
most important sub-detectors.
Its main functions are:
Precise momentum measurement
Good reconstruction efficiency for short
tracks from interaction point
Realization of charged particle trigger at level
one
26. The chamber is designed to consist of two parts, an inner chamber and an
outer chamber. The inner chamber can be replaced if it malfunctions due to
radiation damageThe inner diameter of the drift chamber is 118 mm for
easy assembly of the beam pipe. The physical outer diameter is designed to
be 1600 mm to achieve good momentum resolution
27. The Electro-Magnetic Calorimeter (EMC) plays an
important role in the BESIII detector, whose
primary function is to measure precisely energies
and positions of electrons and photons.
The calorimeter is composed of one barrel and
two endcap sections, covering 93% of 4¦Ð. There
are a total of 44 rings of crystals along the z
direction in the barrel, each with 120 crystals,
and 6 layers in the endcap, with different number
of crystals in each layer. The entire calorimeter
have 6272 CsI(Tl) crystals with a total weight of
about 24 tons.
28.
29. The BESIII muon counter is a gaseous detector
based on Resistive Plate Chambers(RPCs).
The muon detector consists of endcap(east
and west) and barrel. There are 8 detecting
layers in endcap and 9 in barrel, for each
layer, it is made up of one superlayer, in
which two RPC layers and one pickup strip
layer are compacted as Sandwich. The total
amount of RPC units is 978, and the yielding
area is up to 1272m2
30.
31.
32. In this project all detectors which are used in
High Energy Physics, are discuss to the point.
Every detector has its own applications and
benefits in practically.
These detectors are most important to solve
many Physical problems. These detectors
having strong worth in Physics. Later on the
main applications of these detectors are
discussed. At the end main High Energy
Physics labs are also discussed which are
using now a day these detectors in their labs.
