E-201 CCR THZ CHARACTERIZATION RUN
PLAN
Updated: 06/26/14
Shift leaders: Gerard Andonian, Brendan O’Shea, Oliver Williams (UCLA)
1. CCR, CTR and THz measurement
Goals:
Characterize the ability of a coupling system to get radiation out of the Kraken.
THz energy measurement, CCR spectral scan, CTR bunch length measurement
Estimated time: 8hrs
Tubes installed:
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10cm long SiO2 cylindrical 450 um inner diameter
10cm long Quartz cylindrical 400 um inner diameter
10cm long Quartz cylindrical 300 um inner diameter
15cm long Quartz cylindrical 400 um inner diameter
15cm long Quartz cylindrical 300 um inner diameter
Beam Configuration:
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Beam Orbit: <100um tolerance at E201 IP (for 10cm and 15cm long
structures)
Beam Charge: 1E10 - 2E10 in linac
Beam Size: <100x100µm – at E201 IP (for entire length of 10cm or 15cm
structure) (60umx60um target if achievable)
Rep rate: 1-10 Hz FACET
Beta functions such that beam gets through length of structure (10 cm or
15 cm)
Beam must stable such that it does not hit the structure during the time
when the structure is in the beam path [Note: we have found that with
dispersion Etax & Etay: < 5 mm in IP region, we are relatively immune to
a klystron dropping out (for example)]
Waist location: E201_10 (kraken)
Full Compression, Full charge, Max current
Initial conditions need to be as fully documented as possible before
handing over (for example emittances)
Number of Shifts estimated: 1.5 shifts
CCR Procedure Details: (~1hr per scan, ~1 hrs between samples)
1) Establish beam as above and document to elog
2) Measure beam size and centroid on IP2A, IP2B
3) If can get wire scans on WSIP1,2 and 3, estimate size at waist. If not estimate
from IP2A, B and KOTR. Note: may not be able to get three wires with the
10x100 betas
4) Confirm beam alignment of HeNe, and beam to centroid marks
5) Look at beam with KOTR – take background image of KOTR mirror (if
possible)
6) Turn beam OFF (send to scav line or 2-9 dump)
7) Move sample holder to OTR screen
8) Turn beam ON – take mark on KOTR (if possible)
9) Turn beam OFF
10)Move to 1mm pilot hole (aka “big hole”) – view surrounding phosphor screen
on HALO
11)Turn beam ON – grab image –investigate for angle, or beam halo on phosphor
12)Move to 500um pilot hole (“small”) – repeat
13)Turn beam OFF (to scav line so feedbacks keep working)
14)Move sample block to 1cm long circular structure using HeNe and optimize
for HeNe throughput
15)Turn beam ON 1Hz
16) Symmetrize fiber glow/halo looking at KOTR
17) Collect BLIS data (with external 6” mirror retracted)
18)Repeat scan for foil target (CTR bunch length scan)
19)Monitor/record energy modulation in beam
Completion criteria: CCR spectral scan, CTR scan for bunch length.
CCR energy measurement
1) With structure still in place, insert external large turning mirror
2) Monitor/record data from energy meter (pyroelectric)
3) Move stepper stage (6”) through “focus” and record data; record position
where absolute energy does not change
Repeat both CTR, CCR spectral and energy measurements, and beam energy
modulation for the different length structures!
Milestones:
1. Users measure spectral profile and total THz energy for all cylindrical
structures.