NSRL Data Library for Run 13B
This is the data repository for transferring data files out of NSRL.
A study was made for the PHENIX ZDCs. A 1 GeV/n Silicon beam was prepared, with ~1 cm cylindrical Gaussian profile. The beam intensity was reduced to approximately 4000 ions per spill (300 milliseconds). A trigger counter was installed just upstream of the ZDC module. It was a plastic scintillator measuring 1x1 cm^2 and 2 mm thick. It was used to measure the flux of silicon ions, as well as provide an ADC gate for integrating the ZDC signal. The trigger signal was split using a passive splitter, with the analog signal being delayed 50 ns and integrated by the ADC. The HV on the trigger scintillator was adjusted to give 100 mV signal for the Silicon ions at the input to the ADC, and a trigger was generated using the other half of the trigger signal with a discriminator set at a 30 mV threshold. The discriminator pulse width was set to 100 ns wide, and this was used as the ADC gate.
The ZDC signal was also split using a passive splitter, and its signal was discriminated at the -30 mV level. The output of the ZDC discriminator was plugged into a scaler to count the ZDC pulses above threshold. The other half of the analog ZDC pulse was delayed 50 ns is a delay cable box, and sent to the ADC where it arrived ~40 ns after the arrival of the Gate signal.
The first data runs were taken with the Silicon beam traversing the ZDC module sideways. There were some large signals observed, but mostly the pulse height distribution looked like a long tail on the pedestal. These data runs are available, but are not posted to this web site. They can be obtained on request.
The second set of runs were taken with the Silicon beam entering the ZDC through the front, as a 100 GeV neutron would. We performed a voltage scan, in 50 volt steps from 1850 down to 1700. A pedestal run was also taken. Those files can be downloaded below.
The headers of the files contain a description of the event records that follow. Each event is comprised of 7 integers.
The first is an accumulative scaler that counts the number of pulses above threshold that the ZDC discriminator has received.
The second word is the spill number of that event (also accumulative).
The third word is the ADC value from the trigger scintillator.
The fourth word is the ADC value from the ZDC.
The fifth word is nonsense.
The 6th and 7th words are the event time is seconds and nanoseconds since Bill Gates started counting...
As an example, I have included the first event record from the file Si_1000_21_6_2013_006.ascii.
Additional data were taken using a 1 GeV/n Fe-56 beam, same size and configuration as the Si-28 beam above. Data files are listed below.
Here is an image of the irradiations:
Last Modified: June 25, 2013