Industrial Accelerators Section

Injector Microtron for Indus-1

A 20 MeV, 30 mA Microtron is used as electron injector for the booster of the synchrotron radiation facility, Indus-1. The Microtron (fig.1) is basically a cyclic accelerator having a dipole magnet of diameter 1370 mm.Ph A uniform magnetic field of 1820 Gauss with uniformity better than 0.2% is generated inside the dipole magnet to rotate electrons in circular orbits.Ph A radio frequency cavity (type II), which resonates in TM010 mode at frequency of 2856 MHz, is placed at the position of common tangent to all orbits. A cylindrical pin of 3 mm diameter and 3 mm length made of lanthanum hexa Boride (LaB6) is used as electron emitter. Under the influence of electromagnetic field of RF cavity these electrons are accelerated to higher energy and gains energy of 0.87 MeV, every time when electrons repeatedly passes through the cavity. The electromagnetic field of cavity is responsible for electron emission, capturing and focusing. The Microtron is in regular operation for feeding the 20 MeV electron beam to the booster of Indus-1.

Main Parameters of Injector Microtron

Beam Energy

20 MeV

Energy Spread

0.2 %

Pulse Current

30 mA

Pulse duration

1-2 usec

Pulse repetition rate

1 -3 Hz

Beam size inside Microtron

3mm X 5 mm

Number of orbits


Electromagnet diameter

1370 mm

Mean pole gap

105 mm

Weight of Electromagnet

2011 kg

Magnetic field strength

1820 G

Microwave Source


Power of Microwave Source

5.0 MW max

Operating Frequency

2856 MHz

Voltage in RF cavity

0.98 MV

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