These Agilent Varian 4UHV ion pump controller with part number 9299010 have one high-voltage HV channel providing 200 Watt at negative polarity (1 x 200 W Negative Polarity). It is important when ordering to be informed that the 4UHV ion pump controller can be purchased with up to four high voltage channels in different output power ratings with a maximum sum total power of 400 Watts. It is also important to know that the output polarity is NOT field adjustable on these 4UHV controllers, you must select an appropriate part number with desired output polarity, e.g., (Diode & Noble Diode) need positive voltages, while Triode style elements (old style Triode & StarCell) need negative voltages for operation. All part numbers of the Agilent Varian 4UHV ion pump controllers operate on 100 - 240 VAC input power and have the Fischer HV connector and are designed to work continuous duty with the medium and large ion pumps, e.g., 20, 40, 55, 75, 150, 300, & 500 l/s pumps.

The New Agilent 4UHV Ion Pump Controller
The new state-of-the-art Agilent 4UHV Ion Pump Controller operates up to four pumps simultaneously and independently. The 4UHV starts and controls ion pumps of any type (Diode, Noble Diode, StarCell) and size (from 20 to 500 l/s). A large four-line LCD display allows simultaneous reading of individual pump voltage, current and pressure. The variable voltage feature ensures optimum pumping speed and pressure reading throughout the operating pressure range. Built-in set points, remote operation and RS232/485 computer interface are standard (Profibus and Ethernet optional).

Optimized Pumping Speed
The 4UHV will select the right operating voltage to optimize the pumping speed of your ion pumps. By applying High Voltage in accordance with operating pressure, pumping speed performance is improved. This is because the energy with which the ion bombards the cathode is the nominal applied HV, reduced by the space charge effect due to the electron cloud present in the ion pump cell. Since the space charge effect is pressure related, a variable HV is applied to maintain optimum bombardment energy, resulting in the best possible pumping performance at any pressure.

Versatility
The 4UHV is available in different configurations, in order to independently power, control and monitor any combination of multiple pumps of different sizes , from one to four pumps, from 20 to 500 l/s. For each number of pumps to be operated several options are available, 120W or 200W for a single pump, 2 x 80 W or 2 x 200 W for two pumps, 2 x 80 + 200 W for three pumps, 4 x 80 W for four pumps.

Safety
To protect you against high voltage the cable is equipped with an interlock system which immediately shuts down the high voltage when the plug is removed from the pump. The protect mode limits the current to protect the pump and the controller.

Pressure Reading
The 4UHV is preprogrammed to automatically convert current reading of any Vaclon Plus pump into pressure. Thanks to its ability to detect ion current as low as 10 nA, it allows pressure measurement in the 10-10 mbar range. To ensure reliable pressure reading down to the UHV region, the 4UHV optimizes the applied high voltage as a function of pressure. As a result, the leakage current of the ion pump is eliminated, thereby providing more accurate pressure readings.

Intelligence
To access the unit you can use analog or RS232/485 ports. The controller uses the same protocol as our other intelligent vacuum devices (Navigator turbo pump Controller and Inverter scroll & rotary vane pumps), giving you fast, convenient access to all elements of the vacuum system. Profibus and Ethernet communications are optional.

Low noise
To protect you against high voltage the cable is equipped with an interlock system which immediately shuts down the high voltage when the plug is removed from the pump. The protect mode limits the current to protect the pump and the controller.

How much power do I need for my ion pumps?
Power requirement depends on the pump size and starting pressure; the larger the pump and higher the starting pressure, the higher the power consumption. The largest standard Ion Pump configuration, 500 l/s, can be easily started with 200W up to 1-5 mbar, while a medium size pump (75 l/s) needs less than 80 W to be started at the same pressure, and 80 W are sufficient to operate a 500 l/s in the typical Ion Pump operating range (below 2-6 mbar).

Why was the higher power rating necessary in the past?
In the past ion pumps were started with the aid of sorption pumps, able to reach 10-4 mbar only. As a consequence, much larger and more powerful Ion pumps controller were needed. The resulting life of Ion Pumps started at such high pressures was much shorter (1 minute of operation at 10-4 mbar is equivalent to 2 months at 10-9 mbar) Today’s oil-free turbo pumps, backed by oil-free primary pumps, achieve lower pressures, thereby reducing the starting pressure of the ion pump. This reduces the maximum power requirement of the ion pump controller and extends the lifetime of the ion pump.

Negative or positive?
The requirement of negative or positive potential depends on the pumping element installed in the ion pump. Diode style elements (Diode & Noble Diode) need positive voltages, while Triode style elements (old style Triode & StarCell) need negative voltages for operation. As stated above the output voltage polarity is NOT a selectable parameter with 4UHV ion pump controllers, you must select an appropriate part number with desired output polarity (see user's manual and catalog section below).