1 / 4

RF parameters for the BNL and CEA cavities

RF parameters for the BNL and CEA cavities. *calculated with the “accelerator definition”. **http://rcalaga.web.cern.ch/rcalaga/704MHz/. Eacc =25 MV/m I 0 = 40 mA j s = 15°. Q ext (CEA) = 1.2*10 6 Q ext (BNL) = 1.3*10 6. Response time of the RF fields:. t cav (CEA) = 0.54 ms

levia
Télécharger la présentation

RF parameters for the BNL and CEA cavities

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. RF parameters for the BNL and CEA cavities *calculated with the “accelerator definition” **http://rcalaga.web.cern.ch/rcalaga/704MHz/ Eacc=25 MV/m I0 = 40 mA js = 15° Qext (CEA) = 1.2*106 Qext(BNL) = 1.3*106 Response time of the RF fields: tcav (CEA) = 0.54 ms tcav(BNL) = 0.59 ms tcav=2QL/w0 ≈ 2Qext/w0

  2. RF power provided to the cavities Variation in exp(1-t/tcav) Variation in 1-exp(-t/tcav) BEAM PULSE AND EACC IN THE CAVITY vsTIME Beam pulse length : LP-SPL : 0.9 ms* BEAM PULSE Dt=0.9 ms *https://twiki.cern.ch/twiki/bin/view/SPL/SPLparameterList RF PULSE AND EACC IN THE CAVITY vsTIME RF pulse length : CEA : 1.27 ms BNL : 1.31 ms RF PULSE Dt+tcav*ln2  Provided RF power : BNL = CEA + 2.7 %

  3. Energy dissipated in the cryogenics G(CEA)≈G(BNL) Q0 = G/Rs Q0(CEA) ≈ Q0(BNL) Rs(CEA)≈Rs(BNL) (only depends on material and surface treatment) • The total energy dissipated in the cavity corresponds to the integration of Pcav all along the pulse • depends on tcav(variation of Eacc) • depends on r/Q BEAM PULSE AND PCAV IN THE CAVITY vsTIME •  Calculations show that the dissipated energy is 10.7 % higher in the BNL case than in the CEA case

  4. Comparison between BNL and CEA cavities, from the point of view of the r/Q • This shows how a lower value of r/Q increases the RF energy supplied to the cavities and the cavity losses dissipated in the cryogenics • This concerns the fundamental mode at 704 MHz • What about the HOM ? • A more detailed report on this calculations has been written

More Related