thhor_crs/gretel.org

* GRETEL

** Channel map

| ADC | Ch | det    | shaper | gain | pin | csa     | PA gain |
|-----+----+--------+--------+------+-----+---------+---------|
| A   |  0 | HETB1L | A      | 1×   |  13 | L33     | 4.3pF⁻¹ |
| A   |  1 | HETA1L | B      | 1×   |  14 | L31(32) | 4.3pF⁻¹ |
| A   |  2 | HETA1H | C      | 15×  |  15 | L31     | 4.3pF⁻¹ |
|-----+----+--------+--------+------+-----+---------+---------|
| B   |  0 | BGO1L  | A      | 1×   |  18 | L39(40) | 1pF⁻¹   |
| B   |  1 | BGO1H  | B      | 15×  |  19 | L39     | 1pF⁻¹   |
| B   |  2 | BGO2L  | C      | 1×   |  17 | L41     | 1pF⁻¹   |
|-----+----+--------+--------+------+-----+---------+---------|
| C   |  0 | BGO2H  | A      | 15×  |  16 | L41(42) | 1pF⁻¹   |
| C   |  1 | HETA2H | B      | 15×  |   8 | L37(38) | 4.3pF⁻¹ |
| C   |  2 | HETB2L | C      | 1×   |  10 | L35(36) | 4.3pF⁻¹ |
|-----+----+--------+--------+------+-----+---------+---------|
| D   |  0 | HETB1H | A      | 15×  |  12 | L33(34) | 4.3pF⁻¹ |
| D   |  1 | HETB2H | B      | 15×  |  11 | L35     | 4.3pF⁻¹ |
| D   |  2 | HETA2L | C      | 1×   |   9 | L37     | 4.3pF⁻¹ |
|-----+----+--------+--------+------+-----+---------+---------|

** Analog configuration

*** Preamp gain

- BGO: C₂= 1pF, R₂= 100MΩ
- HET: C₂= 4.3pF, R₂= 22MΩ

*** Sallen Key

- a = 1.47 = C20/C21
- b = 0.46 = R22/R23 = a - 1
- τ = 2.7µs = R20×C20 = R21×C21
- R20 = 27kΩ
- R21 = 39kΩ
- C20 = 100pF
- C21 = 68pF
- R22 = 1kΩ
- R23 = 2.2kΩ

*** Shaper

- τ = 2.7µs = R1×C1 = R3×C3
- τ0 = 100µs = C1×R0 (pole zero compensation)

**** High Gain

- a = R3/R1 = 45
- R1 = 220Ω + 47Ω
- C1 = 10nF
- R3 = 12kΩ
- C3 = 220pF
- R0 = 10kΩ

**** Low Gain

- a = R3/R1 = 3.1
- R1 = 220Ω + 2.4kΩ
- C1 = 1nF
- R3 = 8.2kΩ
- C3 = 330pF
- R0 = 100kΩ