HRRL OTR Test Feb 16th 2011
Objectives
1.) Check alignment of the OTR target and beam line with the linac's central axis. If it is misaligned we will work on an alignment plan to be executed after the Wednesday beam test.
2.) Take OTR images, check image focus and light output.
3.) Determine which quad to use for emittance measurements. Establish a quad current scan range.
Steps
Practise Turning HRRL On
Make document of the whole process, write a Standard Operation Process (SOP).
Turn RF off, Try to see Image with filament on
If we can see filament spot on the OTR target, try to focus our image system.
Turn RF On
Turn RF on look at the images, take pictures of the image upload them to the wiki.
Experiment
First Fusing
Image on OTR target
| Lights | RF | image |
| on | off | 
|
| on (different contrast) | off | 
|
| off | off | 
|
| on | on (27 Hz) | 
|
RF:25-205, Peak Current50mA, Pulse Width_200ns (fwhm)
RF:25, Peak Current60mA, Pulse Width_200ns (fwhm)
RF:50
Light is on
Second Fusing
Focused With Lenses,140 mA 58Hz 100ns
Determine the smallest energy, beam current, pulse width, and rep rate for a visible image.
Visible Image for Lowest Parameters
First Focus
Second Focus
Following images are taken under conditions that: 100 ns FWHM pulse width, 25 Hz Repetition Rate:
Beam off
20 mA peak current image is the lowest noticeable under 100 ns FWHM pulse width, 25 Hz repetition rate.
20 mA Peak Current
30 mA Peak Current
50 mA Peak Current
60 mA Peak Current
70 mA Peak Current
80 mA Peak Current
90 mA Peak Current
100 mA Peak Current
110 mA Peak Current
120 mA Peak Current
140 mA Peak Current
Calculating Current Single Bunch
S-band linac has RF frequency of 2856 MHz. The period then is:
[math]\displaystyle{ T_{RF}=\frac{1}{f_{RF}}=\frac{1}{2856MHz}=350~ps }[/math]
Pulse width of linac: [math]\displaystyle{ \Delta t }[/math].
Number of bunches within a pulse: [math]\displaystyle{ N }[/math]
[math]\displaystyle{ N \times T_{RF} = \Delta t }[/math]
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