RF Tube comparisons and other requirements

1. RF Tube comparisons and other requirements RF ‘Basic technology’ bidRAL, 23 rd Feb 05 S Bowater; D Findlay; D Wilcox

2. Contents • The RF requirements • The projects • Tube data (David Findlay) • Tube technology and frequency range • Typical time-line? • Neutrino factory RF systems requirements • RF systems value over time • Conclusions

3. RF System Requirements

4. Projects • MICE • Neutrino Factory • IFMIF • ESS • RHIC II • E-RHIC • RIA/RIB • ISIS upgrade • FAIR

5. Characteristic Gridded tubes IOTs Klystrons Solid State Notes >1 MW Exist now Don’t exist yet Exist now Don’t exist yet 100 kW – 1 MW Exist now Don’t exist yet Exist now Don’t exist yet 10 kW – 100 kW Exist now Exist now Exist now Exist <10 kW Exist now Exist now Exist now Exist Frequency specific? No Yes Yes No In terms of tube able to operate at one frequency only Structure required Yes Yes Yes No Klystron needs focussing magnet + X-ray shield 0.3–3.0% DF, >1 MW Exist now Don’t exist yet Exist now Don’t exist yet 3–30 % DF, >1 MW Exist now Don’t exist yet Exist now Don’t exist yet CW, 1 MW Exist now Don’t exist yet Exist now Don’t exist yet >1 MW @ 200–250 MHz TH116, Diacrode Don’t exist yet Don’t exist yet Don’t exist yet TH116 modelled in detail at RAL >1 MW @ 250–300 MHz TH116? Don’t exist yet Don’t exist yet Don’t exist yet TH116 modelled at RAL; should go to 280 MHz >1 MW @ 300–350 MHz 4616 OK to >400 MHz Don’t exist yet Toshiba E3740A Don’t exist yet 3 MW ;324 MHz; E3740A developed for J-PARC >1 MW @ 350–400 MHz 4616 OK to >400 MHz Don’t exist yet e2v KP3525 Don’t exist yet 2½ MW 402½ MHz e2v developed for SNS Typical gain 10–20 dB 23 dB 40 – 50dB Drive power ~100 kW 5kW 100–1000 W Pulsed anode HV required No No Yes Pulsed screen required for tetrode Tolerance to reverse RF High Low Need to use circulators for klystrons Manufacturing variability Typical tube lifetime hours 10000–20000 h 30000 - 50000 30000 – 50000 Cost ~£30k (Tube only) £60k (Tube only) ~£300k Efficiency ~50% ~65 - 70% ~60 - 65% Comparison of different tube types in 200–400 MHz region D Findlay; RAL

6. Why different frequencies? • Low velocity, poorly bunched beams • Need large diameter beam tube • Therefore cannot use high frequency • Extravagant on space, low energy gain per unit length and costly. • After phase rotation (tighter bunching) and some acceleration and axial beam confinement • Can use higher frequency • Economical on space, high energy gain per unit length and lower cost

7. Technologies - Useful Frequency Range Multiple beam > MW 1 MW Gridded Tubes Single beam 500 kW Klystron IOT 100 kW DC ~150 MHz ~350 MHz 700 MHz 3 GHz

8. Possible pulsed IOT 2 MW, 200 MHz - 1

9. Possible pulsed IOT 2 MW, 200 MHz - 2

10. ESS – typical project timeline? Assume mid 2008 Beginning 2013

11. Neutrino Factory RF Requirements • Tubes klystrons (?) 12 MW 84 klystrons (?) 5 MW 78 • PSU Cap charger 12MW 123 (?) • Couplers >578 • Cavities -copper (MICE-type) 203 -superconducting type 375

13. Conclusions Need • Better knowledge of status of programmes • Better understanding of detailed device requirements • Better understanding of timescales • To determine realistic target specifications and costs • To look for synergies with other programmes • To prepare an R&D plan with costs and timescales relevant to the overall programme • To complete by mid year?