=Paper=
{{Paper
|id=Vol-2023/239-243-paper-38
|storemode=property
|title=ESIS ions injection, holding and extraction control system
|pdfUrl=https://ceur-ws.org/Vol-2023/239-243-paper-38.pdf
|volume=Vol-2023
|authors=Evgeny Donets,Evgeny Donets,Denis Donets,Nikolay Gorbunov,Dmitry Lyuosev,Dmitry Ponkin,Alexandr Ramsdorf,Alexei Boytsov,Vladimir Salnikov,Ilya Shirikov
}}
==ESIS ions injection, holding and extraction control system==
https://ceur-ws.org/Vol-2023/239-243-paper-38.pdf
Proceedings of the XXVI International Symposium on Nuclear Electronics & Computing (NEC’2017)
Becici, Budva, Montenegro, September 25 - 29, 2017
ESIS IONS INJECTION, HOLDING AND EXTRACTION
CONTROL SYSTEM
E.D. Donets, E.E. Donets, D.E. Donets, N.V. Gorbunov, D.A. Lyuosev,
D.O. Ponkin a, A.Yu. Ramsdorf, A.Yu. Boytsov, V.V. Salnikov,
I.V. Shirikov
Laboratory of High Energy Physics, Joint Institute for Nuclear Research, 6 Joliot-Curie, Dubna,
Moscow region, 141980, Russia
a
E-mail: ponkin@jinr.ru
Electron string ion source (ESIS) KRION-6T is one of the main parts of the NICA injection complex.
During the work on creation of a new ion source for the NICA/MPD project the new ion motion
control system was developed, produced and successfully put into operation.
The new ion motion control system includes pulsed HV potential barriers formation modules used to
hold ions, DC HV power supply, ion extraction subsystem and several secondary modules. Modules
development process and operation results are described.
Keywords: NICA, ESIS, KRION-6T, ion source, high voltage power supply, PID-regulator.
© 2017 Evgeny D. Donets, Evgeny E. Donets, Denis E. Donets, Nikolay V. Gorbunov, Dmitry A. Lyuosev,
Dmitry O. Ponkin, Alexandr Yu. Ramsdorf, Alexei Yu. Boytsov, Vladimir V. Salnikov, Ilya V. Shirikov
239
Proceedings of the XXVI International Symposium on Nuclear Electronics & Computing (NEC’2017)
Becici, Budva, Montenegro, September 25 - 29, 2017
1. Introduction
The main experimental unit of the NICA (Nuclotron-based Ion Collider fAcility) complex is a
collider, designed for the experiments with colliding beams of heavy elements, protons (light ions)
with the nuclei of heavy elements and polarized nuclei beams of light elements (protons, deuterons)
[1].
The Electron String type of Ion Sources (ESIS), was developed, constructed and tested firstly
in the Joint Institute for Nuclear Research [2]. ESIS KRION-6T is currently designed at LHEP JINR
in order to produce heavy ions [3]. KRION-6T operation is based on step-by-step ionization of the
ions by hitting with electrons of an electron string and the main task is to produce the Au32+ ions for
the NICA/MPD project. During the preparation of physics experiments with the ion source KRION-
6T, it is necessary to apply a special barriers for beam ionization and complex signal for beam
extraction.
2. General description
Ions injection, holding and extraction control system contains several types of modules
connected via RS-485 Modbus interface. The system is controlled from PC using Ethernet/optics and
optics/RS-485 converters (figure 1). Each module has its own Modbus ID.
ETHERNET FIBER OPTICS
MODBUS TCP/OPTICS OPTICS/
MASTER RS-458
ID = 104, 105, 106
ID = 100
EXTRACTION
PBF 1
MODULES
POWER
SUPPLY ID = 101
PBF 2 ID = 105
~ 220/24 V MODBUS DEVICE
ID = 102
3 kV isolation .
PBF 3 .
.
ID = 103
MODBUS DEVICE
PBF 4
RS-485
MODBUS RTU
3 kV
Figure 1. Functional diagram of the system
To complete ions holding task, potential barrier formation modules series (PBF) and DC high-
voltage (HV) (HVFM 10.30) modules have been designed, produced and tested. The systems power
supply module was also designed. To complete ions extraction task, extraction modules series were
designed, produced and tested. In addition, several secondary devices were designed, produced and
tested, as well.
The special 24V 3A DC supply module with 4 kV electrical
insulation supplies the system (figure 2). Electrical insulation is
necessary to provide the floating ground of the whole system, which
is required for initial ion beam energy. The specifications:
- Supply: AC 220 V;
- Output: DC 5 - 24V, up to 3 А;
- Electrical insulation: 3 kV;
- Output protection: short circuit, overvoltage, overcurrent.
The module is based on a PWM switching controller TL494.
All the injection, holding and extraction control systems modules are
connected to a single network using flat cable with common +24V
line from this power supply unit. Total current consumption is about
1.8 A.
Figure 2. Power supply module
240
Proceedings of the XXVI International Symposium on Nuclear Electronics & Computing (NEC’2017)
Becici, Budva, Montenegro, September 25 - 29, 2017
The potential barriers formation modules (PBF) are pulsed HV modules with fiber optics
trigger input (figure 3). The main idea of the module is based on a PWM switching controller, which
supplies HV power transformer and HV IGBT transistors. Pulsed HV signal appear on the output at
the time of the input trigger signal is applied. Thus, input trigger signal opens transistor, which is
connected into the output circuit in a key mode.
32-bit ARM MCU performs output voltage and load current measurements, implements
Modbus interface and PID-regulator logic. It allows controlling output voltage magnitude from PC
using 12-bit DAC in the same way as using front panel variable resistor. To improve output signal
linearity the MCU DAC based PID-regulator was implemented. The PBF modules specifications:
- Output: 0 … +3 kV;
- Edges time: ~ 10 us;
- Pulses width: 50 us – 10 s;
- Max load current: 8 mA;
- Supply: + 24 V, 300 mA;
- Overcurrent, short protection;
- Modbus interface;
- Hand & Remote control.
Figure 4 shows +3 kV 1 s pulse output signals difference in
cases of hand mode control using front panel variable resistor and
MCU-based control with PID-regulator.
Figure 3. PBF 10.25 module
trig. signal trig. signal
PID-regulator signal
pulse slope, 1 kV/div
fine pulse, 1 kV/div
Figure 4. PBF 10.25 module output signal: A) hand mode control, B) remote control using PID-
regulator
The DC HV (HVFM 10.30) modules are another ions injection, holding and extraction control
systems elements, which creates static potential barriers, positive potential biases and produce HV
for modulator of the beam extraction system. The HVFM 10.30 modules working principle is also
based on a PWM switching controller, which supplies HV power transformer. MCU logic is the same
as in PBF 10.25 module described above with the only difference lying in input trigger signal
absence necessity. The HVFM 10.30 modules specifications:
- Output: 0 … +3 kV;
- Max load current: 10 mA;
- Supply: + 24 V, 300 mA;
- Overcurrent, short protection;
- Modbus interface;
- Hand & Remote control.
The HVFM 10.30 modules have the same as the PBF 10.25 PC program GUI functionality
shown in Figure 5. User can remotely control the output state, magnitude level and analyze status and
measurements.
241
Proceedings of the XXVI International Symposium on Nuclear Electronics & Computing (NEC’2017)
Becici, Budva, Montenegro, September 25 - 29, 2017
Figure 5. PBF 10.25 and HVFM 10.30 modules GUI
However, from the point of view of the team of authors, the most interesting devices are beam
extraction modules, which consist of the DC HV source (HVFM 10.30), HV modulator (Figure 6)
and capacitive storage device. To complete the operation of the beam extraction it is necessary to
create a special pulse of complex shape in case of slow extraction (100 – 300 us width) and fast
rising edge pulse for quick extraction case (1 – 10 us width). This pulsed potential is applied to one
of the beam drift structure parts simultaneously with of extraction process.
Figure 6. ESIS extraction system HV modulator: A) front panel, B) PCB view
Thus, the HV modulator is a special device, which allows user to create external triggered
complex shape or fast rising edge HV pulse. External trigger is based on the fiber optics to TTL
converter circuit. Fiber optics is used due to the systems floating ground. The main idea of the HV
modulator is PWM-based HV IGBT transistors control. In this case, the transistor output is connected
to the capacitive load and the HV modulator output is connected to the point of their connection.
To achieve a special slope of the pulse rising edge the different duty cycle PWM sections are
applied. As well as duty cycle, user can also specify PWM section width. Thus, user can implement
up to four time slots with different PWM duty cycle. Obviously, the higher PWM signal duty cycle is
the faster is pulse rising edge. This is how pulse complex shape is achieved. Figure 6 shows the HV
modulators PCB a where couple of HV-connectors is shown. The top connector is DC HV in, the
bottom one is modulated signal output. Figure 7 shows two pulses for different beam extraction cases
which have been created using the HVFM 10.30, HV modulator and capacitive storage modules
(beam extraction subsystem).
trig. signal
trig. signal
extraction pulse extraction pulse
1 kV/div 1 kV/div
Figure 7. Beam slow extraction pulse: A) casual, B) complex shape
242
Proceedings of the XXVI International Symposium on Nuclear Electronics & Computing (NEC’2017)
Becici, Budva, Montenegro, September 25 - 29, 2017
3. Conclusion
The new ions injection, holding and extraction control was successfully put into operation
(Figure 8). The basic stand-alone PC software was also designed to control and monitor beam motion
processes. The software was modified according to requests from users after first test run and
currently works without any errors and bugs. It is based on the Visual C# WPF technology where
Modbus RTU over TCP transport class is designed by the authors. The choice in favor of Visual C#
WPF instead of TANGO controls was made based on the real-time HV monitoring requirements. The
next step is to connect the system with ESIS TANGO controls database on the monitoring level. The
group of authors is also going to design similar HV devices with the maximum output voltage up to
±12 kV.
Figure 8. ESIS ions motion control system: A) during KRION-6T work, B) at the test bench
References
[1] A.N. Sisakyan, A.C. Sorin et al. NICA – JINR, 2009.
[2] E.D. Donets, D.E. Donets, E.E. Donets, V.V. Salnikov, V.B. Shutov, S.V. Gudkov, Yu.A.
Tumanova and V.P. Vadeev, Rev. Sci. Instrum., Vol. 75, 1543-1545 (2004).
[3] D.E. Donets, E.E. Donets, T. Honma, K. Noda, A.Yu. Ramsdorf, V.V. Salnikov, V.B. Shutov and
E.D. Donets, «Physics research and technology development of electron string ion sources», Rev.
Sci. Instrum. 83, 02A512 (2012).
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