1. JLEIC SRF update
SRF team

2. Outline Prototype Storage Ring/ERL Cavities Harmonic fast kicker
Magnetic momentum measurement cavity

3. Cavity Fabrication Status
Production of MHz cavities proceeding well
4 cavities in fabrication:
1 Nb 1-cell cavity
2 Cu 1-cell cavities
1 Nb 5-cell cavity
Deep-drawing dies ready (heavy/bulky – hard labor work on press to form half cells)
Need to modify 650 MHz RF measurement fixture for MHz endgroups/dumbbells  in progress

4. Cavity Fabrication Status
Qty.
Material
Nb blanks
for half cells
for beam tubes
Half cells
deep-drawn
Beam
Tubes
Flanges
Endgroups
1-cell 1 Nb
2/2 – wire EDM
completed
wire EDM
2/2 - completed
Completed/
machined
(Nb flanges)
2/2 Welding completed
Waiting for RF trim fixture 2 Cu
4/4 – wire EDM
4/4 - completed
Rolled/
not machined yet
SS CF flanges
- to be ordered
Not yet
Started -
5-cell
10/10 – wire EDM
2/10
(new fixture in place
to ease release of cells)
In stock –
not yet
used
started
Single-cell Nb cavity endgroups ready, getting close to complete cavity

5. Harmonic fast kicker Baseline kicking scheme moving forward:
Frequencies for kicker modes settled, six odd harmonics of 86.6MHz
Needs to finalize other parameters such as kicking angle and aperture
Vacuum model concept in progress
Simplified one cavity 6 modes design
Size similar to Yulu’s ½ model cavity, with 1 additional tuner (5+1)
Asymmetric design: cavity needs to be optimized for minimal longitudinal R/Q
Compatible for UITF/LERF tests
Gun needs to operate at 136MHz reprate

6. Harmonic Kicker Frequencies and UITF/LERF Test
1497 𝑀𝐻𝑧× 7 22 =476.32𝑀𝐻𝑧
CEBAF/UITF/LERF RF
PEP-II or JLEIC e-ring RF
2×476.32𝑀𝐻𝑧=952.64𝑀𝐻𝑧
JLEIC i-ring/ERL RF frequency
476.32𝑀𝐻𝑧 11 =43.3𝑀𝐻𝑧
Baseline JLEIC ERL gun laser reprate
CCR turns
952.64𝑀𝐻𝑧 11 =86.6𝑀𝐻𝑧
harmonic kicker base RF
1497 𝑀𝐻𝑍 11 =136.1𝑀𝐻𝑧
photo cathode laser reprate in UITF/LERF test
136.1 𝑀𝐻𝑍 11 = 86.6 𝑀𝐻𝑍 7 =12.37 𝑀𝐻𝑧
kicked beam reprate in UITF/LERF test
Odd harmonic frequencies of RF kicker: MHz x1, x3, x5, x7, x9, x11 (or x0)
=86.6MHz, 259.8MHz, MHz, MHz, MHz, MHz/DC
CCR harmonic number can NOT be multiple of 11