CIEMAT CONTRIBUTION TO TBL PETS (January 2009) David Carrillo on behalf of the Accelerators Team

TBL - PETS (Test Beam Line - Power Extraction & Transfer Structure) CIEMAT is responsible for TBL PETS prototype PETS should generate 12 GHz RF power in interaction with the drive beam 16 PETS will be placed at TBL to test stability of the decelerated beam

PETS RF designs 30 GHz PETS designed by D.Carrillo (CIEMAT) & I.Syratchev (CERN) 12 GHz PETS designed by I.Syratchev (CERN) Single choke mirror Two waveguide extractor

PETS: General layout Copper rods Power extractor Vacuum port WR90 waveguide Supports Fiducials Cooling pipes

Copper rods Each PETS is made of eight OFE copper rods (800 mm) These are the most difficult parts to fabricate: overall tolerance is +/ mm and roughness should be better than 0.4 micron The coupling cell is smaller: two different tools are necessary Two intermediate thermal treatments to release internal stresses Copper rod

Single rod RF test bench A special test bench has been designed to do RF measurements on each rod Dummy rod phase slip was 121° for 123 cells, that is, about 1° per cell Results agree with 3-D measurements Mode TE 10 HFSS model E field and probe Phase S31 vs position

RF absorbers Several samples from different companies (SiC, AlN composite) were tested at CERN and CIEMAT The present PETS prototype will not have absorbers. Further work is necessary for the future Measuring electrical properties of ceramics RF absorbers

Power extractor It consists of three disks of 140 mm diameter They will be brazed with a 1 mm wire, 78Ag22Cu alloy The waveguides have three flanges, the two outermost of them should be vacuum tight A special test bench has been designed to measure the assembly of rods Mode launchers have been optimized to create the working mode in the PETS, using the coaxial cable coming from the network analyzer A coaxial antenna will measure the field through the slots between the rods Eight rods RF test bench

316LN CF flanges Two pumping ports: ionic and turbo Instrumentation ports: temperature sensors and four for assembly and free for future uses Reference pins at the endplates Vacuum tank Round ¼” OFE copper pipe 1 m/s, 0.3 bar pressure drop, four circuits, 2 ° C estimated temperature increase Vacuum-tight stainless steel connectors brazed to copper pipes, using Helicoflex gaskets Cooling

CIEMAT contribution to a Race Track Microtron: LINAC David Carrillo on behalf of the Accelerators Team

RTM (Race Track Microtron) Layout RTM IORT (Intraoperative radiation therapy ) Electron beam up to 12 MeV CIEMAT is responsible for LINAC (1) Electron gun (2) LINAC (3) (4)end magnets M1 & M2 (5) Quadrupole lens (6) Extraction magnets (7) Extracted beam

RTM (Race Track Microtron) LINAC design Biperiodic structure f = GHz H field E field HFSS model Solid works model Cavity test RF measurements Accelerating cell without nose cones for testing

Conclusions  Eight 800 mm long copper rods (1 PETS) have been machined and will be assembled and measured next month  Two RF measurement benches, both for a single rod or eight ones, have been developed  No material has been identified as a good RF absorber up to now: it is necessary for CLIC PETS  CERN and CIEMAT will share the production of the next seven PETS units to be installed before the end of 2010  CIEMAT is responsible for a small LINAC for an RTM with medical purposes