PVX-4000-2kV-EX Pulsed Voltage Source

1Overview

The PVX-4000-2kV-EX is an air-cooled high-voltage pulse generator built to drive high-impedance capacitive loads. It produces fast bipolar pulses up to plus or minus 2000 V, with the positive and negative excursions sharing a 2000 V budget. The output is designed for extraction grids, deflection plates, and similar electrostatic elements, where the load looks capacitive and the pulse must rise and settle quickly without excessive overshoot.

Unlike the standard PVX-4000-2kV, the PVX-4000-2kV-EX carries no internal HV power supplies of its own. It requires customer-supplied external HV DC sources connected to its rear-panel positive and negative HV inputs — for example, a +1000 V supply on the positive input and a −1000 V supply on the negative input, for a 2000 V total. Freed from generating its own HV internally, the EX variant reaches a higher external-gate repetition rate: single-shot to 600 kHz, versus 100 kHz on the standard unit. Programming is done through the front panel as well as RS-232 and USB computer interfaces.

The PVX-4000-2kV-EX provides the plus or minus 2000 V range, fast and clean rise and fall behavior, and a front-panel plus RS-232 and USB control and monitoring interface. Up to five system configurations can be stored in non-volatile memory and recalled, which makes repeated test setups quick to reproduce. DEI, now a division of Berkeley Nucleonics, originated this pulse-generator line.

2How It Works

The PVX-4000 switches a high-voltage output between programmed positive and negative levels, charging and discharging the capacitive load on each transition. Because the load is capacitive, the achievable repetition rate depends on how much charge the output stage must move per pulse, which in turn depends on the load capacitance and the voltage swing. The Safe Operating Area (SOA) curves capture this relationship directly.

Output can be driven from the internal trigger generator or from an external gate. The internal trigger covers 40 Hz to 30 kHz, the same as the standard PVX-4000-2kV. Because the EX variant does not have to generate its own HV internally, its external gate reaches a much higher ceiling: single-shot up to 600 kHz, versus 100 kHz on the standard unit.

The external gate input is a simple logic-level control: 0 V holds the output off, and plus 5 V turns the output on. With the gate held continuously, duty cycle can reach 100 percent. Pulse shape is fast and clean, with rise and fall times at or below 50 ns over the 500 V to 2000 V span and overshoot held under 2 percent.

3Specifications

All specifications are sourced from the current Berkeley Nucleonics PVX-4000-2kV-EX datasheet.

Safe Operating Area

The Safe Operating Area defines the usable envelope for this pulse generator. For each output voltage, the curve sets the maximum pulse repetition frequency as a function of load capacitance. Stay below the relevant curve to keep the output stage within its thermal and current limits. Remember to add the cable contribution, 1.57 pF per 1.0 cm, to the bare load capacitance before reading the chart.

4Monitoring & Front Panel

The front panel groups the controls and the diagnostic signals needed to set up and verify pulse operation. Trigger source, voltage levels, and gate behavior are configured locally or over the computer interface, and two BNC outputs let an oscilloscope confirm what the generator is doing.

Voltage Monitor

The voltage monitor scales the high-voltage output to a safe, scope-friendly level at 1000 V per 10 V, typical, into a 1 MΩ termination on a BNC. Connect it with RG-58/U 2 ft coax into a 1 MΩ oscilloscope input. This gives a real-time view of the output pulse amplitude and shape without direct contact with the high-voltage line.

Sync Output

The sync output is a 50 Ω BNC that flags output polarity for the scope and downstream timing. A 0 V sync level corresponds to a negative HV output pulse, and a sync level below plus 3.3 V corresponds to a positive HV output pulse. Use it to trigger acquisition in step with the pulse train.

Enable Input

The enable input is a BNC that arms the output. It accepts an external dry-contact closure, or the factory-supplied shorting BNC plug for benchtop use. With the enable open, the output stays inhibited, which supports a simple external interlock.

Computer Communication

The system communicates over RS-232 and USB at 115200 baud, 8 data bits, no parity, 1 stop bit, and no flow control. Up to five complete system configurations can be stored in non-volatile memory and recalled, so repeated experiments and production tests return to a known state quickly.

5Applications

The PVX-4000-2kV-EX is purpose-built for electrostatic modulation of charged-particle beams, where the load is a grid or a plate that behaves as a capacitor and the timing must be precise.

• Time-of-flight mass spectrometry. Drive extraction grids and pulsing electrodes to inject and gate ion packets, where fast, repeatable transitions set mass resolution.
• Accelerator beam steering and gating. Apply pulsed potentials to deflection plates for beam blanking, chopping, and electrostatic steering.
• Ion and electron optics. Switch extraction and lens elements that present a capacitive load and require clean, bounded-overshoot edges.
• High-repetition-rate pulsed electrostatic deflection. Deflect or deflect-and-blank a beam at internal rates to 30 kHz, or under external gate to 600 kHz — the use case that calls for the EX variant over the standard unit.

6Ordering Information

Contact

For a quote, a configuration matched to your beamline or spectrometer, or application support, reach the Berkeley Nucleonics team.

Email: info@berkeleynucleonics.com
Phone: 800-234-7858