From HFML-FELIX Wiki
| Beam | |
|---|---|
| Energy | 18-45 MeV |
| Undulator | |
| period (λu) | 60 mm |
| mo. periods | 46 |
| KRMS (range) | 0.4–1.7 |
| Rayleigh range Mol. beam | 55 mm |
| Rayleigh range FTICR | 82 mm |
| Type | Quasiperiodic PPM |
FELICE is the beam line of FELIX operating from 5–100 µm and allowing intra-cavity experiments.
Procedures
[edit | edit source]Shutdown Procedure
[edit | edit source]- File:Shutdown FELICE quick guide.docx: how to shut down FELICE
- File:Shutdown FELICE.docx: how to shut down FELICE
Attainable wavelengths as function of beam energy
[edit | edit source]| Gap → ↓ Energy (MeV) |
23 | 25 | 27,5 | 30 | 32,5 | 35 | 37,5 | 40 | 42,5 | 45 | 47,5 | 50 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 15 | 143,22 | 122,03 | 101,29 | 85,50 | 73,50 | 64,36 | 57,40 | 52,11 | 48,08 | 45,01 | 42,67 | 40,89 |
| 17,5 | 105,22 | 89,65 | 74,41 | 62,82 | 54,00 | 47,28 | 42,17 | 38,28 | 35,32 | 33,07 | 31,35 | 30,05 |
| 20 | 80,56 | 68,64 | 56,97 | 48,10 | 41,34 | 36,20 | 32,29 | 29,31 | 27,04 | 25,32 | 24,00 | 23,00 |
| 22,5 | 63,65 | 54,23 | 45,02 | 38,00 | 32,66 | 28,60 | 25,51 | 23,16 | 21,37 | 20,00 | 18,97 | 18,18 |
| 25 | 51,56 | 43,93 | 36,46 | 30,78 | 26,46 | 23,17 | 20,66 | 18,76 | 17,31 | 16,20 | 15,36 | 14,72 |
| 27,5 | 42,61 | 36,31 | 30,13 | 25,44 | 21,87 | 19,15 | 17,08 | 15,50 | 14,30 | 13,39 | 12,70 | 12,17 |
| 30 | 35,81 | 30,51 | 25,32 | 21,38 | 18,37 | 16,09 | 14,35 | 13,03 | 12,02 | 11,25 | 10,67 | 10,22 |
| 32,5 | 30,51 | 25,99 | 21,58 | 18,21 | 15,66 | 13,71 | 12,23 | 11,10 | 10,24 | 9,59 | 9,09 | 8,71 |
| 35 | 26,31 | 22,41 | 18,60 | 15,70 | 13,50 | 11,82 | 10,54 | 9,57 | 8,83 | 8,27 | 7,84 | 7,51 |
| 37,5 | 22,92 | 19,52 | 16,21 | 13,68 | 11,76 | 10,30 | 9,18 | 8,34 | 7,69 | 7,20 | 6,83 | 6,54 |
| 40 | 20,14 | 17,16 | 14,24 | 12,02 | 10,34 | 9,05 | 8,07 | 7,33 | 6,76 | 6,33 | 6,00 | 5,75 |
| 42,5 | 17,84 | 15,20 | 12,62 | 10,65 | 9,16 | 8,02 | 7,15 | 6,49 | 5,99 | 5,61 | 5,32 | 5,09 |
| 45 | 15,91 | 13,56 | 11,25 | 9,50 | 8,17 | 7,15 | 6,38 | 5,79 | 5,34 | 5,00 | 4,74 | 4,54 |
| 47,5 | 14,28 | 12,17 | 10,10 | 8,53 | 7,33 | 6,42 | 5,72 | 5,20 | 4,79 | 4,49 | 4,26 | 4,08 |
| 50 | 12,89 | 10,98 | 9,12 | 7,70 | 6,61 | 5,79 | 5,17 | 4,69 | 4,33 | 4,05 | 3,84 | 3,68 |
Cavity Length
[edit | edit source] | Pay attention before changing cavity length When you feel you have to change the cavity length here, please be sure that the US and DS mirrors are properly homed, i.e. that the value you commit is really valid. Make sure that the cavity length is preset to zero at the home position of both mirrors! |
| switches | Molecular Beam position (µm) DS end mirror |
FTICR position (µm) US end mirror |
remarks and dates last checked |
|---|---|---|---|
| home position | 0 | 0 | by definition |
| cavity zero | 271 | -1217 | MB 08/04/2021, FTICR 19/05/2021 |
| negative limit | -1262 | -2246 | MB 03/09/2020, FTICR 09/09/2020 |
| positive limit | 858 | 1130 | MB: 858 is the maximum reachable, after that the motor probably loses contact with the stage (03/09/2020), FTICR: 1330 (09/09/2020) |
(i.e. the stated cavity zero position is relative to the home positions).
Debug info
[edit | edit source]On the upstream side, the homeswitch is active towards the negative limit switch, and inactive towards the positive limit switch. A positive movement of the stepper motor motor corresponds to a longer cavity length. Because of the nature of piezomotors, the step size is not equal in both directions. At the position of the home switch +10000 steps corresponds to +6 µm, and -10000 steps is ca. -23 µm.
Mirror Settings
[edit | edit source]This is specified for the situation where both US and DS mirrors are in home position.
| mirror | Molecular Beam position (steps) | FTICR position (steps) |
|---|---|---|
| DS | H -62 V -129 |
H 97 V -580 |
| US | H -280 V -583 |
H 400 V 160 |
| Angle | H 209 V -180 |
H 250 V 91 |
| End | H 0 V 111 |
H 110 V 76 |
| Last updated | 2021-04-19 | 2021-05-19 |
Diagnostic station
[edit | edit source]Representative output energies
[edit | edit source]
Media:Flc_intensity.pdf Notes on how to convert the outcoupled pulse energy into the macropulse energy within the cavity
Timing & Diagnostic connections on the patch panel in the FELICE hall
[edit | edit source]
- Felice cavity dumping requires a phase-stable trigger pulse: route E5 through the black RF locking box (named _Henny_ in the diagram above).
- The FTICR won't run with short trigger pulses, requires at least 10 us wide pulse
- to enable timer E5 to have long pulse lengths, it should be configured as follows
Troubleshooting
[edit | edit source]- If FELICE does not trigger even though all lights are green, check to see if there is either a) a terminator or b) a BNC cable connected to the top-left BNC connector (M110) on the FELICE patch panel behind the cluster source. It should be open.
- Downstream or Upstream mirror can't be changed (select mirror => Go remains greyed out)? Soft restart of the Subsystem will do the trick. (This button is greyed out for the first few minutes after start of the GUI.)
- Molecular beam specific:
- Is the cavity-dump slab out? (You should be able to see the alignment HeNe on screen 7S60 (near end mirror).)
- Is the experiment not too high? Check for straightness of the bellows between experiment and mirror vessels. Check bestec PC--> Motion control -->V. Value vertical should be between -32 and -28 mm.
- Is the Pyro hooked up well?
- FTICR specific:
- Is the Faraday cup out? (You should be able to see the alignment HeNe on screen 7S80(near end mirror).)
Pictures
[edit | edit source]
