Overview:
DTOTR1 is the high resolution in-vacuum profile monitor immediately prior to the vacuum exit window.
Specs: | |
---|---|
Imaging screens | YAG1: 50 µm thick YAG at 45 degrees, facing DTOTR2 (small depth of field) OTR: silicon wafer, facing DTOTR1 - often suffers from COTR YAG2: 50 µm thick YAG, close to perpendicular to the beam axis, and viewed through a mirror (higher resolution screen!) |
Pixel size |
5.46 um/pxl (as of 05/22/2024) |
Imaging resolution (psf) | 4.5 µm |
Energy resolution | ~0.01% relative |
Instructions for use:
This camera is a scientific CMOS Orca FLASH and is different than the GigE CCD cameras. So the procedure is slightly different for use
- Confirm the camera is on and acquiring:
- From the LI20 Profile monitor panel → click "PYDM All Cameras"
- Select the "CMOS Cameras" tab (Figure 1)
- Confirm that the first camera labeled DTOTR1 is acquiring with 0.001 s exposure
- If not, then click the "Rest CMOS Script" and wait for about 1 minute
- Start Profmon GUI, select DTOTR1 (near end of list), press "Start"
- Position both the camera and screen:
- Open MC01 motor controller (Li20 Profile Monitors → IP2 Table → MC01... OR LI20 Experiment → MC01...) - Figure 2
- Set to the following nominal values:
- DTOTR_X and DTOTR_Y control the target position:
- DTOTR_X = -46.5
- DTOTR_Y = around 144 YAG1 , 64 for YAG2 , or ~100 for OTR
- DTOTR1_X and DTOTR1_Y control the camera position (Focus and height).
- DTOTR1_X = ~0 when view YAG1 or OTR (may be adjusted as needed)
= ~48 when viewing YAG2 - DTOTR1_Y = 98 (nominal beam axis)
- DTOTR1_X = ~0 when view YAG1 or OTR (may be adjusted as needed)
- Adjust DTOTR1_Y in steps of 5 mm if the beam is not seen.
- Center the beam on DTOTR1 screen. There is a shallow depth of field, so the beam needs to be centered to be in focus.
- Ask ops to use XCOR 3276 to center the beam horizontally on the screen
- See Figure 3 for centered beam image
- Insert or remove ND2 filter as required - remember that this is a 16 bit camera
- LI20 Profile Monitors → IP2 Table → Flippers 1...
- Use DTOTR1_X to adjust the focus to minimize the imaged spot size - Fig 3
- If you run out of room on this motor then you can move the DTOTR_X motor to change the position of the beam on the screen, and then compensate by moving DTOTR1_X.
Notes:
- Do not set a ROI. This does not work and messes up the DAQ - If you are getting DAQ errors, click Full ROI button.
- DAQs often fail with too many DTOTR1 shots per step. Break up DAQs into multiple steps and do a test to confirm you are getting a good number of matches
Trigger setup:
Found under: LI20 → Event → Profile Monitors ... → SIOC:LI20:PM05...
- TDES = -250000 ns
- Width = 50000
Dump table layout (2023-24):
Figure 1 - PyDM All Camera panel:
Fix this when triggers are re-enabled - There should be 10 Hz rate showing here.
Figure 2 - MC01 motor controller - DTOTR motors are on the right side
Figure 3 - sample image on DTOTR2 (Compressed beam - large energy spread)
Figure 4 - Ladder setup - 5/22/2024 (beam comes from left)