Electron beam accelerator "MIC"

 

  "MIC" is microtron electron beam accelerator characterized by high beam current, low emittance, low energy distribution, and lightweight, compared to linear accelerator (LINAC). Taking advantage of these characteristics, the product is a highly effective portable, nondestructive testing device.

 

  The device alone is shorter than 1m in lateral dimension and is suited for onsite inspection of bridges and bridge beams.The product can easily achieve submillimeter X-ray focusing size and can take high-resolution X-ray images. MIC lineup includes models with energy in the range of 1〜20 MeV.

 

 

 

 

The picture above shows our magnetron-based model, 1MeV MICROTRON X-ray emission apparatus “MIC1".

 

 

 

MIC Focus Size

 

  We have measured the X-ray focus size of the microtron electron accelerators MIC1 and MIC6. The result was an amazing 0.2 mm. The limit for LINAC is 1mm. Such a small focus size is possible because of the well-aligned electron energies, which enable X-ray imaging with extraordinary resolutions.

 

 

 

 

This is an example of the MIC X-ray CT scanning device configuration including beam line and shielding.

 

 

 

MIC Lineup

 

1 MeV

4 MeV

6 MeV

10 MeV

20 MeV

  1mev
4mev
6mev
10mev
20mev
Energy
[MeV]
0.5 - 1.5 3.5 - 4.0 5.0 - 6.0 8.0 - 10.0 12.0 - 20.0
Beam current
500 mA 250 mA 200 mA 200 mA 150 mA
Beam power
max 10 kW max 10 kW max 20 kW max 20 kW max 20 kW

 

 

 

 

Principle of Microtron

 

■Principle

  In a microtron accelerator, the electrons revolve in a uniform magnetic field and accelerate each time they pass through the electric field of the accelerator cavity. Once the accelerated electrons reach a predefined energy level, they are expelled as a beam via an exit pipe to an external device.

 

 

 

 

■Characteristic 1

  In our MIC, as shown in the diagram above, the electron gun that generates the electrons is embedded in the accelerator cavity; this configuration has enabled us to simplify and miniaturize the system, compared with a conventional electron gun.

 

 

 

 

■Characteristic 2

  Linear accelerator (LINAC) accelerates electrons in a straight line, which increases the energy dispersion by 5%, resulting in a large focus size due to energy spread, even if a convergence magnet is used.

  Microtron, on the other hand, accelerates the orbiting electrons selectively, based on the energy level. This makes the acceleration efficient and limits the energy dispersion to only 1%. Unlike LINAC, there is no low-energy component. These principles make sub-millimeter X-ray focus point size possible.

 

 

 

Comparison microtron and linac

4MeV Microtron

 

4MeV Linac

 

mic
linac
mic_spectrum
linac_spectrum
1) Electrons are emitted by RF electric field. 1) Electrons are emitted by 25kV high voltage.
2) Electrons circulate under the uniform magnetic field and are accelerated passing through the cavity. 2) Electrons are pre-bunched by the buncher for matching the acceleration phase in the cavity.
3) Electrons are extracted by the magnetic shield channel after reaching the designed energy. 3) Electrons are accelerated passing through linear acceleration cells.
4)Electron energy is defined by the geometry between acceleration point, extraction channel and magnetic field. 4) Electrons are extracted through the exit hole. Electron energy is defined by the RF power.
*Lower energy electrons are not extracted. *Lower energy electrons are also accelerated.
*Energy spread is 1%. *Energy spread is 5%.

 

 

 

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