The document discusses the Pelletron electrostatic generator, which accumulates electric charge to create high electric potentials for accelerating subatomic particles in nuclear medicine. It describes the operational mechanism, components, and advantages of the Pelletron, highlighting its usage in various institutions in India and its global presence. The Pelletron systems are noted for their reliability, efficiency, and longevity with minimal maintenance requirements.

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.