CH HPGe Electronics Chain

Summer 2022 Efficiency Measuremets

1. Output 1 of HPGe → fan in/out

2A. 1st fan in/out output → spec amp

3A. Spec amp output → ADC input

2B. 2nd fan in/out output → timing filter amp

3B. Timing filter amp output → discriminator input

4B. Discriminator output → negative input of gate/delay generator 1 & → negative input of gate/delay generator 2

5B. Negative output of gate/delay generator 1 → ADC Gate

5C. Negative output of gate/delay generator 2 → Readout card port 1

Discriminator Settings

Note that when using a timing filter amp, the effective level of discrimination is adjusted. The timing-filter amp used (table below) has a minimum amplification of ~2.3x. To keep things consistent with using the unaltered pre-amp signal from the HPGe detector, the threshold is divided by the gain set by the timing filter amp and will be referred to as the Effective Threshold.

Discriminator Threshold (mV)	Gain	Effective Threshold (mV)
30.2	N/A	30.2
30.2	~2.4	12.58
30.4	~2.8	10.86

List of Modules

Module	Brand	Model Number
Fan in/out	CAEN	N625
Spec-Amp	Ortec	672
ADC	CAEN	V785N
Timing Filter Amp	Ortec	474
Discriminator	LeCroy	821
Gate & Delay Generator 1	Ortec	416
Gate & Delay Generator 2	Ortec	416
Readout Controller	SIS GmbH	SIS3820

Past

HPGe → Split signal using BNC T junction

→ First line to spec amp -> peak sensing ADC

→ Second line to timing/filter amp with ~2.3x amplification (also inverts)

→ Discriminator (Blue lecroy model #xxxx)

→ Top of dual timer then into bottom of dual timer

→ Into 1st gate and delay generator

--> positive sent to second gate and delay module

--> negative sent to PADC as gate for spec amp signal

→ 2nd gate and delay generator used for ROC signal

---

Previous Page

CaGaS Phase II

PAS Feasibility Study Runs

CH HPGe Efficiency