1. RF System and EBIS of RAON
JaeEun Han
IF & RF Team

2. Contents RF System - Introduction to RF System of RAON EBIS System
- Low Level RF
- High Power RF
- 1 kW SSPA Simulation & RF Power Test
- 2 kW Unit Test
- 5 kW RF Power Test
EBIS System
- Introduction to EBIS System of RAON
- Breeding Simulation Result
- Electron Gun Simulation Result
Summary

3. RF System of RAON

4. Low Level RF The RF input has 4 identical channel.
ADC has sampling rate higher than 120 MHz.
Calculation of magnitude and phase errors using the output signals of the ADC are performed in the FPGA.
The RF output signal is generated through the FPGA, DAC, IQ modulator and a low-power RF amplifier.

5. High Power RF Schematic diagram of Solid state power amp. for QWR
To produce the power of 2 kW, two modules of 1 kW SSPA are combined, and another 2 way combiner is used to generate RF power of 4 kW

6. Simulation of 1 kW SSPA Circuit Diagram for 1 kW SSPA (Using ADS code)
Most MOSEFT is limited by 500 W of RF power  push pull mode

7. Test of 1 kW SSPA

8. Comparing the result of simulation with test
Power vs. Gain
Test Result
Simulation Result
In comparison with simulation, measurement does not show the peak of power gain near 55 dBm, but the value is not far different.

9. 2 kW Unit Test RFIN Test Result (Spectrum Analyzer) 2 kW Unit SMB035
2-WAY SPLITTER
2-WAY COMBINER 3W
AH-101
AH-202
SMB036
RFIN
Test Result (Spectrum Analyzer)
2 kW Unit

10. 5 kW High Power RF Test SSB034 (5KW) SSB035 (2KW) RFOUT RFIN
4-WAY SPLITTER
4-WAY COMBINER
2-WAY SPLITTER
2-WAY COMBINER
SMB035
(1.2KW)
SMB036
AH-101
AH-202
300W
RFIN
RFOUT
SSB036 (Drive & 4-way Combine)

11. Power versus Frequency (W/ Spectrum Analyzer)
5 kW RF Power Test Result
Power versus Frequency
(W/ Spectrum Analyzer)

12. EBIS System of RAON Electron Collector and Ion extractor
Drift Tube Structure
Electron-Gun
EBIS operation mechanism
Electron beam is generated in electron gun, and ion beams having +1 charge enters drift tube, and then, this electron impact ion beam.
As a result, highly charged ions are created in the drift tube
By controlling potential, electron beam is dumped to collector, and ion beam goes back where they come out.

13. Design parameter for RAON EBIS
RISP Test EBIS
Breeding efficiency
30 %
A/q
> 4
Breeding time
50 ms ( Light Ion)
150 ms (Heavy Ion)
Beam purity
< 0.1 pA
Ion Beam Intensity
2 X 10^9/pulse
Pulse width
10 ~ 20 us
Repetition rate
2 Hz

14. Charge Breeding Simulation
CBSIM
Input Variable
Description
NORDER
order number of Element,(H,U,etc)
ENERGY
energy of electron beam
ALPHA
neutral influx: 0 < alpha < 1
DELTAU
radial potential in electron trap
HEAT
toggle for electron-ion-heating
dens
electron current density
logT1
begin of log10(T)-axis
logT2
end of log10(T)-axis
logTc
time for onset of compensation
Nstep
steps of integration < 5002
ERROR
error criterion for Runge-Kutta
LOGSCALE
log scale for abundances
logP1
begin of log abundance axis
logP2
end of log abundance axis
LABEL
Labels at closed shells
RECOMB
radiative recombination toggle
CHEXCH
charge exchange toggle
mbar
background pressure for ChEX
Epgas
ionization potential of background gas
NSPECT
number of charge spectra
WSPECT
resolution for charge spectra

15. Charge Breeding SimulationSn
1s22s22p63s23p64s24p64d105s25p2
K shell : keV
L shell : keV
Electron atomic binding energy
Sn+41
Sn+30
Sn+31
Sn+32
Sn+33

16. Charge Breeding Simulation
Sn+47

17. Charge Breeding Simulation
Charge exchange and
radiative recombination effect excluded.
Sn+32
Sn+30
Sn+31
Sn+33

18. Charge Breeding Simulation
Sn+47
Sn+32
Sn+30
Sn+33
Sn+31
If we take into account expected A/Q value less than 4 for Sn 132, its charge state is around 33+. Its abundance will be approximately 20 %

19. Electron Gun parameter
Current
(A)
AK Voltage
(kV)
Perveance
(uP)
Cathode diameter
(mm)
Currentdensity
(A/cm^2)
electron beam energy
(keV)
BNL EBIS 10 50
0.9
9.2
575 20
MSU EBIT
1.4
11.5
1.1 3
　104
16.5
2.4
1.9 6
REX EBIS
0.5
6.5 1
125 5
RAON EBIS Electron Gun parameter
Current
0 ~ 10 A
AK Voltage
0 ~　50 kV
Current Density
500 A/cm2
Electron Beam Energy
20 keV

20. Simulation Result (Using E_gun code) - AK Voltage = 50 kV
Current density anode exit)
Electron beam Trajectory
Electrode
Anode
Radial direction
Cathode
Electron Beam
Current, I = A
Average current density J = 144 A/cm2
Cathode radius
8.2 mm
Perveance
1 uP

21. Theory (Child Langmuir law)
Changing AK Voltage
AK Voltage (kV)
Current (A)
Theory (Child Langmuir law)
Simulation Result 10
1.01 20
2.86
2.84 30
5.25
5.23 40
8.08
8.13 50
11.29
11.23

22. Simulation Result - optimization
Electron beam Trajectory
Current density drift tube exit)
50 kV
20 kV
50 kV
Drift tube
Post anode 0V
Anode
Cathode radius
7 mm
Perveance
0.96 uP
Drift tube radius
20 mm
Current, I = 10.2 A
Average current density J = 2570 A/cm2

23. RF System EBIS System Summary
- The design of Low Level RF is optimized.
- 5 kW RF power test is done.
EBIS System
- I have to study more Breeding Simulation.
- The design of Electron Gun is optimized for
Pierce gun type.