This is one of the interesting topic in physics. These pelletron accelerator is a modern thing of van de graff accelerator.

1. by,
A.K.Raaha Sutha
Lady Doak College

2. It is an electrostatic generator.
It can accumulate electric charge on a
hollow metal globe, creating very high
electric potentials.
This high potential is used to accelerate
subatomic particles to high speed & to
generate energetic particle and x-ray
beams in nuclear medicine field.
Turnout: open air van de graaff =5MV,
Industrial machines are enclosed with
pressurized tank of insulating gas=25MV.

3. The basic pelletron inductive charging system
was invented by Dr.James A.Ferry
Pelletron is an accelerator for electrostatic
particles.(charge generator)
Output voltage: small units-500kV &beam
energy-1MV.
It is a collaborative project between BARC &
TIFR has been serving as a major facility of
heavy ion accelerator based research in India.
30000 accelerators in operation around the
world.

5. The system is enclosed by a pressure vessel filled with
insulating gas(SF6) &an evacuated beam line.
A chain of pellets used for carrying charge to the
terminal hence it is called pelletron.
The negative ions on traversing
through the accelerating tubes from the column top of
the tank to the positive terminal get accelerated.
Energetic negative ions stripped by the stripper foil.
Positive ions are repelled away from the positively
charged terminal and are accelerated to
ground potential.

6. Same terminal potential is used twice to
accelerate the ions.
The ions are bent into horizontal
plane by analyzing magnet, which also selects
a particular beam of ion and charge state.
The switching magnet diverts the high
energy ion beams into a pre-selected beam
line of
various beam lines
The entire machine is computer controlled
and is operated from the control room.

8. These systems have fragile electronics in the
high voltage column .
Difficulty: To diagnose and expensive to repair.
Pelletron chains made upon metal pellets.
It connected by insulating nylon links.
Parts: Pulley(30-60cm diameter),suppressor
electrode, high voltage terminal.
Charging current -100-200uA.

9. Low beam current application.(except very high
DC electron recirculation pelletron)
High precision AMS measurement-500kV to 5MV
The design of multi cathode SNICS(Source of
Negative Ions by Cs-Sputtering) source for the
use of both gas and solid samples within a single
source.
New diagnostics is being developed for very low
beam currents.
Latest design of the low current beam profile
monitor(LCBPM) will also be presented.

10. Pelletron above 5MV:
Tata institute of fundamental research-14UD in
Mumbai, India.
Inter –University Accelerator centre(IUPAC)-
15UD in New Delhi, India.
Pelletron with 3MV:
Institute of Physics-9SDH-2 in Bhubaneswar
,India.

12. 300 pelletron chain assemblies in use in 24
countries.
National Electrostatic Corporation(NEC) has
manufactured 79 ion beam systems.
17 of these pelletron systems were designed
with MeV ion implantation capability.
8 were designed for production ion
implantation with max beam energy of 4 MeV.

13. Excellent voltage stability.
No spark damage intrinsically protected.
High efficiency
No electronic diagnostic equipment required.
Virtually insensitive to moisture.
Long life(over 50000 hours reported).
Simple and reliable.
Proven to over 30MV.