Nuclear Instrumentation

CEU 2014 Waikoloa Resort Hawaii

Nuclear Instrumentation & Signal Processing Mohammad W. Ahmed TUNL REU Lecture What is all this mess ?

Closer Look Seems to be some organization in this mess

Instrumentation

Detectors Electronic Modules Computers

Instrumentation Signal Processing & Logic Event Reconstruction Signal

Interaction Picture Signal Signal Processing Event Reconstruction

Positive TTLNIM LongShortNegative Bi-polar DC ECL

Amplitudes (Pulse Height = Peak Voltage); Time (Duration = dt, Start time, t0; Charge Q iR + Q/C = V o dQ/dT + Q/RC = Q o /RC … Q = (V 0 /R e – t/RC ) t 

Gamma-Ray of 1.46 MeVGamma-Ray of 2.61 MeV V T V T  V V   V Example 1

Counts Energy (MeV) Energy = Constant X V  Acquiring the Constant is called Energy calibration

d1 d2 Example 2 d0 T Time-of-Flight (TOF) is differnt

Example 3 Pulse Shape Gamma-Rayneutron Start Time is the same, Amplitude is also same Charge (Q) is different (Pulse Shape Discrimination PSD) T V

Making Copies Passive SplittingActive Splitting Simple “T” Electronic Module Linear/Logic Fan In/Out

Linear Fan In/Out Modules

Logic Creation (Yes/No) Presence of a signal Define the condition for a signal to be valid e.g., If the absolute amplitude is greater than 0.5 V than the signal is good = V TestResult YES ! IN Out YESNO Discriminator the

Logic Modules

Gain IN CG FG T Out Spectroscopy Amplifier “SpecAmp”

Amplifiers

Coincidence Did the two gamma-rays originate from the same source at the same time ? AB A B A+B A B False True A+B

Coincidence IN Outputs ABCDABCD Logic Inputs Logic Output Coincidence Unit

Analog to Digital Convt (ADC) / DAC ADC (to computer) (From device) (From computer) DAC (To device)

ADC Mask the signal by Bits 0 bit 8 bit Amplitude (0 to 10 V) is ranged from 0 to 8192 ADC Counts (for the case of 13 bits) 0 bit 13 bit More bits means better resolution !!!

Logic Gate ADC Linear Inputs

ADC

Scalers; Gate & Delay Generators; Pulse Generators; Filters; High Voltage Generators; Level Adaptors etc.

Fan IN/OUT, Disc., Amplifiers, etc ADCs, TDC, Scalers, etc

BNC “T” BNC Term. LEMO “T”LEMO Term. BNC Barrel BNC to LEMOLEMO Barrel

Where are all the cables and connectors in the Control Room ?

Acquire and process data DAQ and Analyzer DAQ is responsible of taking data from the electronics