CNGS Prot on Beam Line I nst rument at ion OUTLI NE 1. BPM System - - PowerPoint PPT Presentation

NBI2003 - Rh. Jones (CERN - AB/BDI) 1

CNGS Prot on Beam Line I nst rument at ion

OUTLI NE

• 1. BPM System Update
• Requirement s
• Acquisit ion syst em
• 2. BCT System Update
• Requirement s
• Acquisit ion syst em

For other systems see NBI 2002 talk by R. Jung

NBI2003 - Rh. Jones (CERN - AB/BDI) 2

CNGS Beam Posit ion Monit oring

CNGS Beam Position Measurement Requirements

18 But t on Elect rode BPMs in TT41 60mm Apert ure

110 340 110

BPCKD (double)

short circuits BEAM

4 St ripline Couplers in TT40 will see bot h LHC & CNGS beams Original Modif ied I n t e n s i t y R a n g e : 1 ×1

1 2t

• 3

. 5 ×1

1 3

NBI2003 - Rh. Jones (CERN - AB/BDI) 3

CNGS Beam Posit ion Monit oring

CNGS Beam Position Measurement Acquisition System

LP Filt er LP Filt er A B Logamp I t o V Conver t er Dif f . Ampli Posit ion = K * Vout Logamp I t o V Convert er BP Filt er BP Filt er LP Filt er LP Filt er LP Filt er LP Filt er A B Logamp I t o V Conver t er Dif f . Ampli Posit ion = K * Vout Logamp I t o V Convert er BP Filt er BP Filt er BP Filt er BP Filt er

• Each signal is compressed by a logarithmic amplif ier, f iltered and applied

to a dif f erential amplif ier.

• The position response is: Pos ≡ [log(A/ B)] = [log(A)- log(B)] ≡ (Vout) where

Vout is the voltage dif f erence between the log- amp outputs

NBI2003 - Rh. Jones (CERN - AB/BDI) 4

CNGS Beam Posit ion Monit oring

CNGS Beam Position Measurement Acquisition System

Pickup

(BPK/BPG) Down Up Right Left

200MHz 200MHz Att 200MHz 200MHz Att 200MHz 200MHz Att 200MHz 200MHz Att

Calibrator Auto Trigger Sequencer V Integrator S Integrator H Integrator

Analog Multiplexer

ADC Manchester encoder

Log Amp

Logic

Directional Coupler Directional Coupler Directional Coupler Directional Coupler

3 Way Splitter 3 Way Splitter 3 Way Splitter 3 Way Splitter U + D + L + R

Left - Right Up - Down

Log Amp Log Amp Log Amp Log Amp Log Amp Log Amp Log Amp

200MHz BP f ilters Logarithmic Amplif iers 2 in parallel per elect rode t o improve linearit y

1 cable t ransmit s:

• H posit ion
• V posit ion
• I nt ensit y

NBI2003 - Rh. Jones (CERN - AB/BDI) 5

CNGS Beam Posit ion Monit oring

CNGS Beam Position Measurement Acquisition System Why t his choice?

⇒ low cost – as it requires only 1 coax cable per pick-up. ⇒ large dynamic range wit hout requiring gain swit ching. ⇒ simple engineering ⇒ aut ot rigger capabilit y

Pot ent ial Problems:

⇒ linearity with position

• log amp has inherent non-linearit y in t he % of apert ure range
• hopef ully improved using a compensat ion log amp in parallel

⇒ radiation issues with digital electronics in the tunnel

• Experience gained f rom t est ing LHC component s
• At t empt t o use radiat ion t olerant component s

NBI2003 - Rh. Jones (CERN - AB/BDI) 6

CNGS Beam Current Monit oring

CNGS Beam Current Monitoring Requirements

T w

• M
• n

i t

• r

s – o n e a t t h e b e g i n n i n g &

• n

e a t t h e e n d

• f

t h e l i n e A b s

• l

u t e A c c u r a c y

• f

1 % f

• r

t h e I n t e n s i t y R a n g e : 1 ×1

1 2t

• 3

. 5 ×1

1 3

New development f or LHC - Fast BCT (BFCT)

• 500MHz Bandwidt h

→ Not required f or CNGS

• Low droop (~0.1%/ µs)

→ 1% ef f ect f or CNGS

First BCT sees both LHC & CNGS beams

• Has t o f ulf ill addit ional requirement of

LHC bunch by bunch capabilit y (i.e. 25ns resolut ion)

NBI2003 - Rh. Jones (CERN - AB/BDI) 7

CNGS Beam Current Monit oring

CNGS Beam Current Measurement Acquisition System Analogue Acquisit ion based on a f ast int egrat or chip

→Designed by t he Laborat oire de Physique Corpusculaire, Clermont - Ferrand f or use in t he LHCb Preshower Det ect or. (Large Hadr on Collider

beaut y experiment f or precise measurement s of CP violat ion and rare decays)

BFCT Signal after 200m of Cable Integrator Output

25ns

BFCT Signal after 200m of Cable Integrator Output

25ns

→Uses int erleaved, 20MHz int egrat ors and sample & hold circuit ry t o give 40MHz dat a (only t ot al sum required f or CNGS)

NBI2003 - Rh. Jones (CERN - AB/BDI) 8

CNGS Beam Current Monit oring

CNGS Beam Current Measurement Calibration

Fast BCT f itted with calibration winding. Switched current source injects 128mA f or 5µs

• equivalent t o 2×1010 charges in 25ns
• same signal level as a CNGS t rain of 8.4×1012 prot ons

300 320 340 360 380 400 420 440 460 1000 2000 3000 4000 5000 6000 Time in Cycle (ms) Intensity (x10^10) DCCT_SPS BFCT_SPS

Comparison bet ween DCCT and BFCT in t he SPS Shaded region represent ±2%