SLIDE 1
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino)
Use of multi wires chambers in air for profile measurements of intensive beams at IHEP (Protvino)
SLIDE 2 4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 2
Neutrino beams at IHEP
- 1. ν (anti-ν)-inclusive scattering,
structure functions, νe-νµ universality, exclusive channels
- 2. prompt neutrinos
- 3. νe-oscillations with Neutrino
Calorimeter SKAT Bubble Chamber (up to 1990); JINR-IHEP Neutrino Calorimeter νµ , anti-νµ focused beam; beam-dump; short decay path Up to 1.4x1013 (booster), 29 bunches, 5µs spill duration 1985
- 2003
- 1. µ-pairs in ν-interactions;
- 2. search for short-lived particles
using nuclear emulsion;
- 3. σtot(νN), quasi-elastic scattering,
including limits on νµ-oscillation parameters, νµe-scattering, etc.
- 4. prompt neutrinos (charm production
in pFe-interactions) ITEP Spark Neutrino Detector νµ , anti-νµ focused beam; beam-dump Up to 2x1012, 30 bunches, 5µs spill duration 1974
Results Detector(s) Neutrino beams Proton beam Years
SLIDE 3 4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 3
Construction
Mechanical construction of cham ber ( type A)
116 wires
1 2 15 16
Vbias Vbias
116 wires
Vbias
a d b c 1 2 15 16
Y profile Beam
3 mm 120mm 156mm 1 16
element b element a and d X profile
SLIDE 4
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 4
Construction - 2
Main param eters of cham ber A and B 116 wires, 1mm step, beryllium-bronze alloy 116 wires, 1mm step, beryllium-bronze alloy Bias plane 16 strips, 140mm working area 14 central + 2x12 wires connected in parallel, 38mm working area Construction Signal electrode 3mm 3mm Distance between signal and bias plane 1mm 0.8mm Distance between wires/strips 40 x 8mm wire of ∅ 200 Size aluminum beryllium-bronze alloy Material Chamber B Chamber A
SLIDE 5
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 5
Electronics
Schem atic draw ing
chamber 20m ADC + memory
Tim ing diagram
τ ≥ 100µs beam digitalization 5µs 5-10µs 5µs Time Signal
SLIDE 6
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 6
Measurements (vacuum)
Originally the chambers were used inside of beam pipe under a pressure of ~ 10-2 torr Beam profile for focused (chamber A) and wide beam (chamber B)
Channel number Channel number
16 mm 140 mm
Beam profiles
Chamber A Chamber B
Num ber of δ-electrons
Number of -electrons per proton (measured with Vbias= 0): chamber A – 0.03, chamber B – 0.01
SLIDE 7
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 7
Measurements (vacuum) - 2
Linearity
Chamber signal, relative units 1.0• 1013 Beam intensity, protons/ cm 2
Chamber A spill duration varied from 20 ns to 5s chamber signal is a sum of 14 central wires signals intensity measured by BCT Vbias= 0 the same dependency was observed for chamber B too
SLIDE 8
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 8
Measurements (vacuum) - 3
Dependence of signal on pressure and bias voltage
chamber signal is a sum of all wires signals
Bias voltage, V Chamber signal, relative units
P ~ 1 Torr P ~ 2x10-1 Torr P ~ 5x10-2 Torr P ~ 5x10-3 Torr for Vbias= 0 the signal is equal for all pressures after first 1-2 years of use all chambers were operated with Vbias= 0
SLIDE 9
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 9
The chambers in air
Focused neutrino beam
beam-pipe target chamber
1985 - 1994
beam ~ 5m ~ 5-7m
Short decay path beam
target absorber chamber beam-pipe ~ 10m
~ 1996
beam
SLIDE 10
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 10
Measurements (air)
Proton intensity in 1012 protons per spill (5s) Proton intensity in 1012 protons per spill (5s)
Linearity
Chamber signal, relative units Chamber signal, relative units
SLIDE 11
4th workshop on NBI, 7-11 November 2003 Valeri Falaleev(CERN) & Yuri Sviridov (IHEP, Protvino) 11
Summary
The m ulti w ires cham bers w ere usefully used during m any years in vacuum and air for profile m easurem ents of intensive proton beam s.
