mardtb 248x110
Edited on 10-Aug-2018

11. metaljet

11.1 Introduction


The "metaljet"-page can be accessed by selecting the corresponding tab in the main window. Here, you can control the metaljet generator (Excillum MetalJet source).

This page is accessible only if:

11.2 Control of Excillum Generator

The MetalJet generator by Excillum can be operated by a PC through a network socket. Program 'mardtb' does not talk directly to the Excillum interface but to the safety control box manufactured by marXperts. This safety control box operates:

The safety control box can be operated by a variety of programs:

While several programs can talk simultaneously to the safety control box, it is suggested to only operate it from one place close to the instrument. In particular, it should be avoided to open the shutter remotely without visual contact to the instrument since this might involve the risk of physical damage to humans however small this scenario might be.

The interlock system comprises signals from:

The interlock system generates a single signal, either OPEN or CLOSED. The safety shutters can be operated ONLY if the interlock system is CLOSED - unless the safety system is deliberately bypassed. Under normal conditions, if the interlock system is OPEN, the safety X-ray shutters will be closed automatically and cannot be opened until the status of the interlock system is CLOSED.

11.3 Operations

There are only 4 useful states of operation of the X-ray generator:

Hence, from the user interface you select one of the 4 states. Setting the high voltage or current to other than the default values is possible only via the native generator control interface provided by Excillum.

If the high voltage is turned on, in the control area within field "Run mode" you will see a "High Voltage" icon in yellow. If the generator is in STANDY mode at lower power, the icon will show a light grey background. At high power, the background turns yellow as shown in the picture.

If X-rays are leaving the generator, i.e. if the HV is on and the generator shutters are open, a yellow "Radiation" icon will show up on the right hand side of the push buttons for the shutters.

Opening the shutter is only possible, if the interlock system is CLOSED. If it is open, the shutter button is insensitive and an exclamation mark appears on its right hand side as show in the picure.

In the main status window of the mardtb GUI, the field for the status of the generator shutter is color-coded and has the following meanings:

Run mode Shutter Label
OFF Open

Besides those 3 basic generator operation modes (OFF, STANDY and FULL POWER), the CALIBRATION cycle is recommended to be repeated every 24 hours. This procedure is taking about 3 minutes and optimizes the position of the electron gun.

11.4 Data Collection Options


In the "Data collection options" area of this page, you have a choice of taking special actions after finishing a data collection. Choose one of:

In order to increase the lifetime of the cathode it is beneficial to let the generator run in FULL POWER mode not longer than necessary. Hence, it is suggested to automatically go into STANDBY mode after data collection or - even better - to turn the X-rays OFF. You have to keep in mind, that it does not take longer than 1 minute to go back into FULL POWER mode, so even if you plan to resume work shortly after a data collection has finished it would still make sense to go into STANDBY.

Likewise, if you don't plan to resume work for a couple of hours, you might as well turn off the X-rays at all.