RF scheme of electron linear RF scheme of electron linear accelerator with energy 200-500 MeVaccelerator with energy 200-500 MeV

Levichev A.E.Budker Institute of Nuclear Physics SB RAS

IntroductionIntroduction

Debuncher-monohramatorDebuncher-monohramator

Accelerating structureAccelerating structure

Accelerating structure.1 – Regular cell, 2 – Wave type transformer, 3 – Connection cell, 4 – Connection

diaphragm, 5 – Structure frame with cooling system.

Accelerating structureAccelerating structure

BINP produced accelerating structure.

Accelerating cells and wave type transformers.

Operating frequency f 2855.5 МHz

Operating mode

Unloaded quality factor Q0 1.32104

Group velocity Vgr 0.021C

Shunt impedance Rsh 51 МОhм/м

Unloaded time 0 = 2Q0/ 1.47 μs

Attenuation parameter = 1/(0Vgr) 0.108 1/м

Integrated attenuation parameter L 0.316

Filling time Tf =L/ Vgr 0.465 μs

Period 34.98 мм

Inner diameter of the cell cavity 83.8 мм

Iris aperture diameter 25.9 мм

Iris thickness 6 мм

Overvoltage coefficient 1.7

Basic parameters of BINP made accelerating structuresBasic parameters of BINP made accelerating structures

RF power sourceRF power source

Picture of TH 2100 klystrons series.

Operating frequency 2856 MHz

Peak output power 45.5 MW

Average power 10 kW

RF pulse duration 4.5 μs

Gain 54 dB

Efficiency 43 %

Maximum input power 200 W

Band width 10 MHz

Cathode voltage 315 kV

Beam current 335 А

Filament heater voltage 30 V

Filament current 24 А

Basic parameters of TH 2128 C/D klystron.

ModulatorModulator

Parameter Unit K2-1 K2-2 K2-3

Klystron RF Peak Power approx MW 35 40 45

Klystron RF average Power approx kW 1,6 1,6 1,6

modulator Peak Power MW 74,3 91,5 100,5

modulator average Power kW 4,3 5,0 5,1

Pulse voltage kV 270 300 314

Pulse current A 275 305 320

Pulse repetition Frequency range Hz 1-10 1-10 1-10

Pulse Length (top) ìs 4,5 4 3,5

Flatness % ± 1 ± 1 ± 1

Repeatability % ± 0,2 ± 0,2 ± 0,2

Parameters of К2 modulator series (ScandiNova Systems)

Modulator К2-3

Power compression systemPower compression system

Cavity diameter D 196 мм

Cavity height H 346.6 мм

Operating frequency f0 2856 МHz

Range of mechanical tuning f 5 МHz

f/H 2.75 МHz/мм

Quality factor Q0 95000

Unloaded time 0 11 μs

Loaded time TC = 0/(1+) 1 μs

Moment of phase switching 3 μs

RF pulse duration from the klystron 3.5 μs

Power multiplication coefficient К0 7.29

Main parameters of BINP made power compression system.

BINP made SLED type power compression system

0 1 2 3 4 50

1

2

3

4

5

6

7

8

Reflected power Pref

(t)

Input power Pinp

(t)

P(t)/Pgen

t[mcs]

Measured input and reflected power from SLED system cavitiesMeasured input and reflected power from SLED system cavities

Sub harmonic bunching systemSub harmonic bunching system

Sub-harmonic bunching cavity is used to bunch beam before bunching cavity with main frequency. In our case the frequency of sub-harmonic cavity can be chosen as main frequency divided by 8 (357 MHz) or by 16 (178 MHz). To decrease cavity sizes it can be performed by toroidal form. The loss power of cavity is 2-5 kW. The amplifier tube can be used as power source for the cavity. Such power source supplies sub-harmonic cavity with frequency of 178 MHz in preinjector complex VEPP-5 in BINP SB RAS.

RF buncherRF buncher

Internal cells diamters 2b 81.9 mm

Iris diameters 2a 23.8 mm

Iris thickness t 5 mm

Period D 48.7 mm

Unloaded quality factor 3350

Shunt impedance 0.389 MOhm

Coupling factor 1.3

Cavity dimensions Electrodynamics cavity parameters

Electric field in RF buncher along beam axis with storage energy of 1 J RF buncher design

RF scheme for the first and second accelerating structuresRF scheme for the first and second accelerating structures

RF scheme for all accelerating structures except the first and RF scheme for all accelerating structures except the first and second structuressecond structures

Attenuator and phase shifterAttenuator and phase shifter

I – double T-bend, II – waveguide with two plungers 1` and 2`

Wave amplitude depends on the length between plungers and doesn’t depend on common distance

The phases depend on common distance and don’t depend on the length between plungers

RF scheme of debuncher-monochromaticRF scheme of debuncher-monochromatic

Operating frequency 2856 MHz

Pick output power 10 MW

Average power 10 kW

RF pulse duration 3.5 μs

Gain 50 dB

Efficiency 48 %

Maximum input power 200 W

Band width 10 MHz

Cathode voltage 168 kV

Beam current 124 А

Filament voltage 15 V

Filament current 15 А

Parameter Unit K1-1 K1-2 K1-3

Klystron RF Peak Power approx

MW 6 7 10

Klystron RF average Power approx

kW 3,0 4,1 6,4

modulator Peak Power

MW 14,7 17,8 22,6

modulator average Power

kW 10 15 20

Pulse voltage kV 140 155 170

Pulse current A 105 115 133

Pulse repetition Frequency range

Hz 30-300 30-300 30-300

Max PRF at max Peak & average P

Hz 112 148 183

Pulse Length (top) ìs 4,5 4 3,5

Flatness % ± 1 ± 1 ± 1

Repeatability % ± 0,2 ± 0,2 ± 0,2

Basic parameters of the klystron TH 2163 A Parameters of modulators (K1 series)

Modulator of К1 series (“ScandiNova Systems”)