DPPMCA Display Acquisition Software

All hardware parameters can be accessed by clicking the “Acquisition Setup” toolbar button. Controls are grouped by tabs. “MCA” tab controls acquisition presets, number of channels, LLD (threshold), setup of single channel analyzers (SCA’s), etc. “Shaping” tab controls peaking time, flat top, baseline restoration, pile-up rejection, and risetime discrimination. Common controls also set by shortcuts. Gain can be controlled by increment and decrement buttons on the toolbar, or by setting a specific value in the Setup display. “AutoTune” controls are available to automatically tune key parameters, such as the input offset and the fast and slow thresholds. Customized hardware configurations may be stored as .cfg files. DPPMCA is shipped with a library of .cfg files for the common configurations of Amptek’s detectors.

Display and User Interface

All functions can be accessed via the command menus. Many functions are also accessed by toolbar buttons. Includes “hot keys” for the most common functions, i.e. starting and stopping acquisition, rescaling the display, setting ROIs, etc. User control of display parameters such as log vs. lin scaling, auto-scaling, zoom along the energy axis, setting colors and grids, and many more. Oscilloscope mode displays pulse shapes for tuning of hardware parameters.

Spectrum Analysis

User can set regions of interest (ROIs) for peaks. Software computes centroids, FWHM, net area, and other quantities. Data are displayed on the screen for the selected ROI or in a table for all ROIs. Simple energy calibration, using two points or a linear regression for multiple points. Typically based on the centroids of known ROIs. Includes capability for simple arithmetic manipulation, e.g. subtracting a “blank” or “background” spectrum, scaling to match previous data, etc. For quantitative X-ray analysis, DPPMCA includes an active link to the XRF-FP software sold by Amptek. For other sophisticated spectral analyses, the data are saved in an ASCII format, that most software will recognize. Data can also be copied to the clipboard and pasted, e.g. in Excel.

System Requirements

Supports Microsoft Windows XP SP3, Vista, Windows 7, Windows 8, Windows 10, Windows 11. DPPMCA will run under both 32 and 64-bit versions.

Installation

After downloading the .zip file, extract the executable "DppMCA_Setup_X.X.X.XX.exe" wherever is convenient and run it. Windows may prompt you with a warning which will require you to click "more info" then "run anyway". You will need to accept the End-User License Agreement and select an install directory.

For Digital Pulse Processors (DPP) like the DP5, PX5, X-123, or Gamma-Rad5, you will have to install the WINUSB driver. Please see the DPP installation instructions.

Quick Use

Please read the Quick Start Guide for your product. It contains specific instructions for the operation of your device. The information below is generic to DPPMCA. There are different options depending on the product in use.

Changing the Gain: This changes the full scale energy range.

A common task is to change the energy range of a system. This is done by adjusting the gain of the amplifier. A lower gain corresponds to a higher energy range, and a higher gain to a lower energy range. For example, in Amptek’s digital systems a gain of x100 may correspond to a 15 keV full scale and a gain of x50 to a 30 keV full scale. To adjust the energy range it is always the gain of the system that must be changed. It is not enough to change the software calibration only. The software calibration is only in software. If the software’s calibration is changed without the amplifier’s gain changing appropriately, the software will be displaying the wrong energy range and peaks will be incorrectly identified.

If you are using one of Amptek’s digital processors (DP5, X-123, Gamma-Rad5 etc.), the gain is adjusted through the DPPMCA software on the Gain & Pole Zero tab of the DPP Properties, or by using the gain buttons on the toolbar It is necessary to readjust the thresholds whenever the gain is changed. This can be done automatically by starting an acquisition (pressing space bar) and clicking the “Tune Slow/Fast Thresholds” button on the toolbar of the DPPMCA application with no source exciting the detector. See the quick start guide of the appropriate product for more information.

Calibration: Changing the Channel scale to Energy.

Once the appropriate gain (full scale energy) is found, the software can be calibrated. The software must always be calibrated in order to change the channel scale into an energy scale. To accurately calibrate a spectrum there must be at least two known peaks in the spectrum. For example, an iron (Fe) peak at 6.40 keV and molybdenum (Mo) peak at 17.48 keV. It is best to use peaks that are on the two ends of the energy range of interest. Peaks that are too close together may not produce an accurate calibration. For example, do not use Mn at 5.9 keV and Fe at 6.4 keV to calibrate a 30 keV full scale.

To calibrate the scale in the Amptek DPPMCA software follow these steps:

• Chose the two peaks that will be used for the calibration and make note of their energies.
• Mark an ROI (region of interest) around each peak. This can be done by clicking the cursor at the left base of the first peak and then holding down the “U” key on the keyboard until the whole peak is highlighted, or by using the Edit ROI button on the toolbar and then clicking and dragging across the peak until it is highlighted. For more information on marking ROIs please see the Help file under Analyzing Data with the DPPMCA Software → Regions of Interest and How to Define Them.
• Now click in the toolbar button “Calibrate” to open the calibration dialog box.
• Move the dialog box such that both peaks are visible and then click the cursor into the first peak. The peak should be highlighted and the Peak Information section on the right-hand information panel should be filled in. If the peak is highlighted and there is no peak information, then the ROI is not marked correctly. Try adjusting the start and end points of the ROI.
• Click the Centroid button on the dialog box. This will enter the center position of the peak into the Channel box. Then enter the energy of that peak into the Value box, e.g. 6.4, and click Add.
• Now click the cursor into the second peak (it will highlight). Click on Centroid, enter the second energy, e.g. 17.48, and click Add. There should now be two lines in the box.
• In the Units box type in the energy units, e.g. keV.
• Click OK. The scale should now be in energy. If it is not press F7, this toggles between calibrated units and channels.

For a complete list go to the Help menu and select Keyboard Map. Here are a few:

• The “Space Bar” Starts and Stops an acquisition
• The “A” key clears the data and resets the time
• The "L" key switches between Logarithmic and Linear display modes.
• The "E" key removes a selected ROI
• The "R" key removes all ROI's
• The "T" key open a repeat spectrum setting for logging changes over time.
• Pressing and holding down the “U” key marks an ROI to the right, and the “Y” key marks an ROI to the left
• The "N" zooms out on the energy scale and the "M" key zooms in.
• The up and down arrow keys adjust the maximum counts displayed
• The left and right arrow keys move the cursor to the left and right by 1 channel at a time, but can be held in to continually adjust.
• F1 opens the Help File
• F2 open the communications window to connect to DPP devices
• F3 Starts/Stops acquisition
• F4 Updates data and time information
• F5 open the Calibration menu
• F6 open the Spectra List, useful if dealing with multiple files.
• F7 toggles between the calibration values and the channels for the X axis.
• F8 sets the LLD Threshold (slow threshold) to the current cursor position
• F9 open the Configuration manager, to adjust instrument settings.

Digital Processor Products (DP4, DP5, DP5G, PX4, PX5, X-123 (all versions), Gamma-Rad, Gamma-Rad5, TB-5, MCA8000D, MCA8000A)

Perform the following steps in this order:

1. Sometimes no spectrum (or a distorted spectrum) will appear if the fast and slow thresholds are not set properly. Remove any source from in front of the detector and click the “Tune Slow/Fast Thresholds” button on the toolbar. Put the source back and check if the spectrum appears. The input counts should always exceed the counts. If the auto tune fails, or if the counts exceed the input counts, perform the manual adjustment in the next step.
2. The Fast and Slow Thresholds can be adjusted manually. First turn off pile-up rejection (DPP Properties→Shaping tab). Then click the cursor to channel 1 and press F8. This will set the Slow Threshold (LLD) to channel 1. This will show the noise of the system. Click the cursor just to the right of the noise and then press F8. Press the “A” key to clear. There should be no counts accumulating in the spectrum display. Now put the device into “Delta” mode by clicking the Delta button on the toolbar. Open the DPP Properties and go to the Shaping page. Adjust the Fast Threshold until 1 to 15 counts per second appear in the Input Counts in the right-hand Info Panel. Now turn on PUR and click OK. Click the Delta button to get back to normal MCA mode and put the source back in front of the detector. The Input Counts should slightly exceed the Counts
3. In the DPP Properties->Gain tab, use the default input offset option
4. Check the High Voltage (HV) of the unit. For Amptek Si-PIN and CdTe detectors the HV polarity must be positive (and the input polarity negative in the DPP). For SDD detectors the HV polarity must be negative (and the input polarity positive in the DPP).
5. If you still have problems, please email Amptek a saved .mca file from the DPPMCA software (see below for instructions)

How to save and email .mca files and diagnostic data to Amptek

1. Make sure you are using the latest version of the DPPMCA software.
2. Power on your device in accordance with its instructions
3. Connect your device with your PC, and connect with the software
4. Click “Help”, then “About DPPMCA”.
5. Click the “Request Diagnostics ” button. Diagnostic data will be dumped into the box; this includes a hex dump of the configuration memory. Select all these values, copy them (Ctrl-C), and save them in a text file. Notepad is a convenient editor. Click “OK” and close out of “About”.
6. Acquire a spectrum for approximately 30 seconds; if there is no spectrum displayed, still save the file as it will contain important information about the system that will help Amptek troubleshoot the problem
7. Go to the File menu and select Save As to save the .mca file.
8. Email both the .mca file and the diagnostic text file to amptek.sales@ametek.com