Transcript Diapositiva 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
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
QUAD
QUAD
POWER EXTRACTION
STRUCTURE
ACCELERATING
STRUCTURES
30 GHz - 230 MW
BPM
Main beam: 1 A, 100 ns
from 9 GeV to 1.5 Tev
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
 Schematic layout of the CTF3 facility:
BPMs
A tentative layout of the
Test Beam Line (TBL) layout
of the CTF3
(M. Gasior, CTF3 Note)
 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
BPM (Beam Position Monitor) unit:
Signal pick-up
Head electronics
Block 1: Front end
Distance 50-150 m
Block 2: Signal distribution
Block 2: Signal Digitalization
Distribution
amplifier
Digitizers
Button pick-up and the (pre-)amplifier
BPMs of the CTF3 linac
The scheme and the PCB
of the drive-beam linac
(M. Gasior, CTF3 Note)
A development of the existing instrumentation is needed:
•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
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)
• Options to consider:
a) Transmission of analogue signal
upgrading of the existing BPM design
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
building prototype + testing
2006
2006-2007
UPC participants
 CMC group (Control,Monitorizaje y Comunicaciones)
(http://cmc.upc.es/)
Prof. Gabriel Montoro
 GRCM group (Grup de Recerca en Comunicacions
Mòbils) (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.