1. ELENA / AD Pick-ups and Schottky
Wolfgang Hofle, 7 March 2019

2. ELENA longitudinal pick-ups (LPU)
Principle follows the design by F. Pedersen for AD
Low frequency version: kHz MHz
High Frequency version: 800 kHz MHz
different types of ferrites are used for the two versions
Wolfgang Hofle, 7 March 2019

3. ELENA longitudinal pick-up assembly
Design: J. Sanchez Quesada, F. Pedersen, F. Caspers, S. Federmann et al.
Mechanical engineering with Central Workshop
Amplifier design and commissioning in BE-RF-FB
R. Louwerse assigned for its performance improvement after
Departure of J. Sanchez Quesada
Help from F. Caspers available
Wolfgang Hofle, 7 March 2019

4. Status of ELENA LPUs Four pick-ups were planned within the project
3 low frequency pick-ups (LF)
1 high frequency pick-up (HF)
The HF and LF Schottky LPU are installed in the ELENA ring
The signals they provide suffer from interference
this is being looked at with priority
Combining the signals correctly for different energies requires an adjustable delay between the two (depending on beam energy) that needs completion (electronics)
The remote control of the gain requires completion of work in BE-RF-CS
The LF pick-up in the extraction line to Gbar (LNE50) was installed in 2018 and has measured the intensity of the extracted bunches through a system of digitization and calibration provided by BI (J.C. Allica Santamaria)
Signals are also available on OASIS (since 2018)
Cabling is prepared for the last of the four pick-ups, a LF version for the LNE00 line
Nota bene: LNE50 LPU has small leak (?); no spare pick-up
Wolfgang Hofle, 7 March 2019

5. Head amplifier powered remotely from the rack
powering through a long cable with feedback to stabilize DC voltage
interference observed and oscillatory behaviour of voltage regulation
mitigation in ELENA ring by local power supply (mid June 2018); reducing regulation bandwidth on electronics implemented during 2nd half of 2018 (R. Louwerse)
Wolfgang Hofle, 7 March 2019

6. Test in June 2018 (LF version in LNE50)
Wolfgang Hofle, 7 March 2019

7. Powering locally from lab supply
Powered from rack with operationally used supply
Powered locally from a lab supply in the ring
LF LPU LNE50
LF LPU LNE50
400 mVpp
20 mVpp
LF LPU Ring
LF LPU Ring
80 mVpp
20 mVpp
Signals without beam, output of pe-amplifier

8. Ring PUs with local powering
Frequency response to be adjusted
Delay for combined signal to be checked
(pbar)
D. Gamba
Wolfgang Hofle, 7 March 2019

9. LF LPU for LNE00 and strategy
Pick-up mechanically completed
Leak tested and accepted by TE-VSC after bake-out
Test stand being prepared for the electrical tests with pre-amplifier in building 112
Wolfgang Hofle, 7 March 2019

10. Completion of electronics and installation
Mitigation of noise and interference through testing in 112 and trying out modifications
Test of operational set of electronics in 112 for LNE00
Test of spare set of electronics in 112 with pick-up
Installation in LNE00 of pick-up and electronics
Repeat measurements to see if situation in ELENA is different from the lab environment
Decision on needed modifications of the electronics and on spare electronics depending on the outcome of the tests (budget from operations, ~10 kCHF may be needed)
Wolfgang Hofle, 7 March 2019