1. UPC participation in the development of BPMs for the TBL of the CTF3 Yuri Kubyshin WORKSHOP ON THE FUTURE LINEAR COLLIDER Gandía, December 3, 2005

2. two-beam acceleration scheme: The acceleration in CLIC is based on a two-beam acceleration scheme:  The high charge drive-beam is accelerated in a low RF linac.  The RF power is extracted from the low-energy and high-intensity drive beam running parallel to the main beam linac via Power Extraction and Transfer Structures (PETS) with a 30 GHz RF field of high gradient 150 MV/m.  The basic principle of extracting RF power and powering the main accelerating structures has been successfully demonstrated in CTF1 and CTF2 Drive beam: 150 A, 130 ns from 1.2 GeV to 200 MeV Main beam: 1 A, 100 ns from 9 GeV to 1.5 Tev

3.  Schematic layout of the CTF3 facility: The goals of the CTF3 are: To demonstrate the drive beam generation (fully loaded acceleration, bunch frequency multiplication) Test 30 GHz RF source (PETS) Demonstrate generation of accelerating gradients of 150 MV/m

4. (M. Gasior, CTF3 Note) BPMs A tentative layout of the Test Beam Line (TBL) layout of the CTF3  TBL of CTF3/CLEX goal is to demonstrate the feasibility of the CLIC drive-beam decelerators at CTF3/CLEX  It will allow to test - Operation procedure - Required instrumentation - Feedback system to ensure the stability of the beam Specific features: High beam current Large total energy spread Large transverse wake-fields in the PETS The beam instrumentation must provide a time resolution of at least 10 ns In order to observe and control the build up of the instabilities along the 140 ns long bunch train

5. Block 1: Front end Block 2: Signal distribution Block 2: Signal Digitalization Distance 50-150 m BPM (Beam Position Monitor) unit: Signal pick-up Head electronics Distribution amplifier Digitizers

6. Button pick-up and the (pre-)amplifier

7. The scheme and the PCB of the drive-beam linac (M. Gasior, CTF3 Note) BPMs of the CTF3 linac

8. A development of the existing instrumentation is needed: These require Broadening of the bandwidth of the analogue signal up to1kHz - 200 MHz Increase of the frequency of sampling till 500 Msamples /s (higher time resolution) with 12 bits per sample (higher amplitude resolution) Higher current: 35 A (3.5 A at the CTF3 linac) Higher bunching frequency: 15 GHz (1.5 GHz) Beam pulse length: 140 ns (1.5 μs) Better time resolution to observe the build up of the instabilities On-line monitoring of the beam behaviour

9. Options to consider: Transmission of analogue signal a) Transmission of analogue signal upgrading of the existing BPM design Transmission of digital signal b) Transmission of digital signal digitalize ‘in situ’, in the front end unit, and transmit the signal in the digital form. Problem: the electronics has to endure a high level of radiation (annual dose about 5 kGy) We are going ♦To analyze the requirements, carry out a feasibility study (taking into account the cost of electronic components, cable connections, etc.) for both options and select one of them ♦ To formulate a proposal, get financing ♦ To start the work …. Tentative schedule: design 2006 building prototype + testing 2006-2007

10. UPC participants  CMC group (Control,Monitorizaje y Comunicaciones) (http://cmc.upc.es/)http://cmc.upc.es/ Prof. Gabriel Montoro  GRCM group (Grup de Recerca en Comunicacions Mòbils) (http://www.gcr.tsc.upc.es/)http://www.gcr.tsc.upc.es/ Prof. Antoni Gelonch ♦ Both groups are from the Department TSC (Teoría de la Señal y Comunicaciones) of the UPC  INTE (Institut de Tècniques Energètiques), UPC Yu. K.