From FELIX Laboratory wiki
| Beam | |
| Energy | 12–25 MeV |
|---|---|
| Undulator | |
| period (λu) | 65 mm |
| no. periods | 42 |
| no. poles | 84+2 |
| gap (range) | 22.6–110 |
| KRMS (range) | 0.4–2.08 |
| undulator type | PPM |
| magnet type | SmCo |
FELIX-1, or FEL1, is the far-infrared or long-wavelength beam line of FELIX operating from 30–140 µm.
Spectral Range vs. Beam Energy
| Beam Energy [MeV] | Min [µm] | Max [µm] | Min [cm-1] | Max [cm-1] | Max pulse width [µs] | Max power [mJ@µm] |
|---|---|---|---|---|---|---|
| 16.6 | - | - | - | - | 12 | |
| 17.7 | - | - | - | - | 12 | |
| 18 | - | - | - | - | 12 | |
| 19 | 33 | 110 | 91 | 303 | 12 | 28 @ 42 |
| 19.6 | 28 | 111 | 90 | 360 | 12 | 45 @ 42 |
| 20.5 | 34 | 100 | 100 | 294 | 12 | range needs verification |
| 22 | 28 | 66 | 151 | 360 | 12 | range needs verification |
| 26 | 18 | 33 | 300 | 555 | ? | 65 @ 24 |
Parameters
Cavity Mirrors
Upstream
The default upstream mirror is M5. For long wavelengths, one of the stronger focussing mirrors M2 or M3 may be selected.
| Mirror | Range (µm) | Offset (µm) |
|---|---|---|
| M1 - | - | - |
| M2 R=2400 | > 120 | 95 |
| M3 R=2650 | > 90 | 260 |
| M4 - | - | - |
| M5 R1=R2 | < 110 | 0 |
Downstream
Check the table for a downstream proper mirror. Mirrors with larger holes will have smaller gain (and therefore slower rise of the optical pulse), but will emit more light at larger wavelengths.
| Mirror | Range (µm) | Offset (µm) |
|---|---|---|
| M1 4mm R=2250 | > 90 | 310 |
| M2 5mm R=2250 | > 100 | 170 |
| M3 2mm | 20–40 | 150 |
| M4 3mm | 30–70 | 20 |
| M5 4mm | 50–110 | 0 |
The position of the cavity zero detuning length should be -840 µm from the positive limit for mirror combination M5/M5. N.B. on 2022/07/11 the cavity zero was +480 µm more than it should have been according to these values. To be checked on the next occasion.
Undulator
See feluc.