Which DAQ card should be used to acquire Gamma rays(pulses)

[GiridharYadav]

Hello everybody,

Can anyone help me in getting out this, My project includes the acquisition and analysis of gamma rays. So, I require a DAQ card to acquire these gamma rays(pulses).

Coming to the characteristics of these pulses

1. Rise time of the pulse = 0.1micro second

2. Fall time (Decay time) = 1 micro second

3. Average pulse rate <= 5000 pulses/second.

4. Amplitude of the pulse will varying between 0 to 5V/(10V variable)

I am using Proportional counter for these pulses detection, the characterisitcs of the pulse are obtained only after signal conditioning what i had.

Analysis of these pulses include two processes

1. Pulse height Analysis.

2. Multichannel scalar(MCS).

1. Pulse height analysis

In this process spectrum of the acquired pulses should be constructed, which contains the peaks. After obtaining the spectrum, we need to select a gamma ray peak over certain amplitude interval. This is known as pulse height analysis and selection of peak. So, from this process pulses of 5v will be obtained which are spaced randomly.

2. Multi channel scalar(MCS)

In this process the pulses obtain from the pulse height analysis should be counted as a function of external variable in the MCS mode of operation.

In this MCS mode of operation, data(pulses) should be stored into 2000 channels (preset channel no's) by recording the data for 100micro seconds in each channel. This cycle should be completed in 1/10 second. The trigger pulse to start this experiment (MCS mode of operation for data logging) will also initiate a square wave for a period 10hz. The data should be collected for over 600 sweeps and should be filed as a seperate data set.

So, for this process to be done using LabVIEW I need the DAQ card details and the appropriate functions for the analysis. I request the person who is going to provide solution, please provide the details of DAQ card and the functions required.

Thanks in Advance

A.Giridhar Yadav

[johnsold]

I looked into doing something similar for the purpose of upgrading a liquid scintillation counter several years ago. For a variety of reasons the project was never completed.

The most straightforward way of doing this is to digitize the pulses at a rate fast enough to capture the peak amplitude and with enough resolution to permit the pulse height measurements to be analyzed. For your pulse specifications this would mean a sample rate of at least 10^7 samples per second. 20 or 25 MHz might be better. The MCS channels are essentially the amplitude resolution of the converter. If your full scale pulse matched closely with the full scale range of the analog to digital (A/D) converter, an 11-bit converter (2048 bins) would be sufficient. However, you probably want to adjust the thresholds of the channel bins slightly so a higher resolution converter would be required. If you can afford it 14-bit or 16-bit conversion would give you flexibility in setting the MCS channel values.

I am not familiar with the high speed data acquisition devices, but a quick look at NI's product pages shows several devices in the Digitizers/oscilloscopes category which might work.

The software would need to locate peaks, determine if they are valid peaks and not noise, then count pulses or sort them into bins base on amplitude.

Lynn

[hrh1818]

On Mar 26, 6:10 am, Gamma ray acquisition <x...@no.email> wrote:
> Hello everybody,
> &nbsp;
> Can anyone help me in getting out this, My project includes the acquisition and analysis of gamma rays. So, I require a DAQ card to acquire these gamma rays(pulses).
> &nbsp;
> Coming to the characteristics of these pulses
> &nbsp;
> 1. Rise time of the pulse = 0.1micro second
> 2. Fall time (Decay time) = 1 micro second
> 3. Average pulse rate &lt;= 5000 pulses/second.
> 4. Amplitude of the pulse will varying between 0 to 5V/(10V variable)
> &nbsp;
> I am using Proportional counter for these pulses detection, the characterisitcs of the pulse are obtained only after signal conditioning what i had.
> &nbsp;
> Analysis of these pulses include two processes
> &nbsp;
> 1. Pulse height Analysis.
> 2. Multichannel scalar(MCS).
> &nbsp;
> &nbsp;
> 1. Pulse height analysis
> &nbsp;
> In this process spectrum of the acquired pulses should be constructed, which contains the peaks. After obtaining the spectrum, we need to select a gamma ray peak over certain amplitude interval. This is known as pulse height analysis and selection of peak. So, from this process pulses of 5v will be obtained which are spaced randomly.
> &nbsp;
> 2. Multi channel scalar(MCS)
> &nbsp;
> In this process the pulses obtain from the pulse height analysis should be counted as a function of external variable in the MCS mode of operation.
> In this MCS mode of operation, data(pulses) should be stored into 2000 channels (preset channel no's) by recording the data for 100micro seconds in each channel. This cycle should be completed in 1/10 second. The trigger pulse to start this experiment (MCS mode of operation for data logging) will also initiate a square wave for a period 10hz. The data should be collected for over 600 sweeps and should be filed as a seperate data set.
> &nbsp;
> So, for this process to be done using LabVIEW I need the DAQ card details and the appropriate functions for the analysis. I request the person who is going to provide solution, please provide the details of DAQ card and the functions required.
> &nbsp;
> Thanks in Advance
> A.Giridhar Yadav

The short answer is none. National instruments doesn't make any data
acquisition cards for this type of measurement. You will be way ahead
by going to a company like Ortec for radiation detection
instrumentation. See: http://www.ortec-online.com/products.htm

Howard

[NuclearPhysics]

Hi ,

 For pulse height measurement with ns - us width, as far as I know there are two ways of ADC, which is possible to do. They are the Charge intergrating ADC (called wilkinsion ADC) and peak sensing ADC. These two types using a caparator determines charge or peak of the pulse. It also needs a hight rate counter. The count number is referred to ADC channel.

 So, for NI, it seems not work. If we still want to use NI, we need to find out a software method analysing. 

 I also want to use NI to develop pulse height analyser. But I am still at dark.

 If anyone has any idea, please share!

Hai

[Current_93]

I'd like to say that among NI devices no such to accomplish full your task, only may be FPGA cards... I I've been working on this issue and now I would advise to use GBS-Elektronik or Toivel cards