Mini-X OEM X-Ray Tube
Figure 1. Mini-X-OEM X-Ray Tube

The Mini-X-OEM is a precision x-ray generator designed for applications that require small size and low power consumption. The source includes a miniature sealed x-ray tube with a transmission-type end window and a high voltage power supply encapsulated in a single radiation-shielded unit. The source is designed specifically to be used as a component of a bench-top or hand-held x-ray spectrometer for the detection of trace elements using x-ray fluorescence spectrometry.

The Mini-X-OEM differs from the Amptek Mini-X. The Mini-X has a USB interface to control the voltage and current through PC software and makes it easy to set up XRF experiments. The Mini-X-OEM version is controlled by the end user, by supplying analog voltages to control the voltage and current of the tube. This is the preferred method in table-top and hand-held OEM applications where all the functions of the instrument are controlled by a single internal computer.

The Mini-X OEM is only available with a detector purchase. It is not sold separately.


  • 50 kV High Voltage Supply
  • 4 W, 200 µA X-Ray Tube
  • Small Size and Light Weight (340 g)


  • Handheld XRF
  • Tabletop XRF
  • Experimental


Technical Specifications


Tube type Metal-ceramic
Tube voltage 5 kV – 50 kV
Tube current 0 – 200 µA, See Figure 2 below
Tube power 4 Watts maximum
Cathode type Tungsten filament
X-ray window Be, 125 µm
Target material Standard: Au, Ag or Rh
Optional: W
Focal spot size Approximately 2 mm
Output cone angle 120°, See Figures 3 and 4 below

Power Supply

Input voltage 6 – 12 VDC range
Input current @ 6 VDC: 1.35 A typical, 1.5 A max
@12 VDC: 0.70 A typical, 0.75 A max
HV stability < 0.1%

Physical Parameters

Radiation shielding Self-shielded (except output window).
Shielding of output window is the responsibility of the customer.
Cooling Conduction, Heat sink to be supplied by customer.
Operating temp -10 °C min, 60 °C max. case temp
Ambient humidity 30 to 90% (non-condensing)
Dimensions Please see mechanical drawing Figure 9.
Weight 340 g
Mounting orientation Any
Collimator and filters Not provided

Mini-X 4W Isopower Curve

Figure 2. Mini-X-OEM 4 Watts Isopower Curve.

Energy (kV) Pin 6 (V) Current (µA)
Pin 5 (V)
10 0.8 200 4
20 1.6 200 4
25 2 160 3.2
30 2.4 130 2.6
35 2.8 110 2.2
40 3.2 100 2
45 3.6 85 1.7
50 4 80 1.6

Table 1. Maximum pin voltages for isopower curve above.

PIN Configuration

PIN 1 V+, (6-12 VDC)
PIN 2 V+, (6-12 VDC Nom.)
PIN 3 Ground
PIN 4 Ground
PIN 5 Tube I Control
Input (0-4 V = 0-200 µA)
PIN 6 Tube HV Control
Input (0-4 V = 0-50 kV)
PIN 7 Filament Ready
(0-5 V, Low = Not Ready, High = Ready)
PIN 8 Tube Enable
Input (0-5 V, Low = Off, High = Enable)
PIN 9 Tube HV Monitor
Output (0-4 V = 0-50 kV)
PIN 10 Tube I Monitor
Output (0-4 V = 0-200 µA)

Mini-X Angular Response, 120° cone
Figure 3. Mini-X-OEM Angular Response, 120° cone.


Mini-X 120° Cone

Figure 4. Mini-X-OEM 120° cone.

The Mini-X-OEM is manufactured and warranted (one year or 2000 hours, whichever comes first) by Newton Scientific Inc.

MX50 USB Controller

MX50 USB Controller for Mini-X-OEM

Amptek suggests that first time customers of the Mini-X-OEM purchase at least one MX50 USB controller. This USB controller interfaces with the Mini-X-OEM and provides easy software control of the unit over USB. This allows for easy troubleshooting, and rapid setup and prototyping.

MX50 USB Controller for Mini-X OEM
Figure 5. MX50 USB Controller for the Mini-X-OEM.

MX50 USB Controller for Mini-X OEM, Rear View
Figure 6. MX50 USB Controller for the Mini-X-OEM.

MX50 USB Controller for Mini-X OEM, Front View
Figure 7. MX50 USB Controller for the Mini-X-OEM.

Mini-X OEM Controller Software Interface Allows User to Set and Monitor Voltage and Current
Figure 8. USB Software Interface. Allows the user to set the voltage and current as well as monitor both parameters.

Radiation Safety


The Mini-X-OEM is intended to generate x-ray radiation during normal operation. The Mini-X has been designed to focus radiation in the designated output direction, however radiation in other directions is possible and should be addressed with shielding and/or monitoring in the final application.


This device produces X-rays when energized.  To be operated only by qualified personnel in compliance with all local health, safety and regulatory requirements.  The Mini-X-OEM is only one component of an X-Ray instrument.  It is the responsibility of the OEM to provide a fail safe metal enclosure or other suitable mechanism to limit radiation exposure while their customers use this product.  The OEM instrument (turnkey XRF analyzer) must comply with local government regulations to protect personnel from exposure to radiation.  Amptek, Inc. bears no responsibility for the incorrect use of this product.

Radiation Levels:

Radiation levels external to the X-ray tube housing with the brass safety plug ON do not exceed 25 µSv/h (2.5 mrem/h) measured 5 cm from the surface of the housing in accordance with Requirement of the National Bureau of Standards (NBS) Handbook for Radiation Safety for X-Ray Diffraction and Fluorescence Analysis Equipment.

For more information please see the NBS Handbook.

Examples of Shielding (that comply with the above standard)

  • 1 mm (0.040 inch) of Pb will result in radiation levels of 0.5 mrem/h.
  • 6.35 mm (0.250 inch) of Fe will result in radiation levels of 0.5 mrem/h.
  • 3.18 mm (0.125 inch) of Brass will result in radiation levels of 2.5 mrem/h.

The inside of the housing can also be lined with 3.18 mm (0.125 inch) of aluminum (Al) in order to absorb the fluorescent X-rays from the shielding material


Mini-X OEM Mechanical Dimensions (in. [mm])
Figure 9. Mechanical Dimensions.

Specifications subject to change without notice.

Mini-X-OEM X-Ray Tube in PDF format