RECENT RADIATION STUDIES ON THE BDIR, DUMPS, LINAC AND TEST FACILITIES
ILC BDS MeetingJune 30, 2006
FermilabEnergy Deposition/Accelerator
Physics
Nikolai Mokhov
Noriaki Nakao
Sergei Striganov
Fermilab
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 2
OUTLINE
1. BDS, Extraction and Beam Dumps 2. Backgrounds in SiD Detector3. Bent Crystals at ATF2 and
Tevatron4. SMTF Test Facility5. Main Linac Cryomodule6. NIU Beam Diagnostics Laboratory
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 3
Thorough Modeling of BDS Collimation & Extraction
• Synchrotron radiation and performance of collimation and extraction
systems (STRUCT, A. Drozhdin and X. Yang).
• Simulations and benchmarking of collimation system with BDSIM, MARS15 and STRUCT (with UK and SLAC colleagues).
• Model refinement and further simulations of radiation loads and radiation environment in BDS, IP and extraction (MARS15).
• Masks and extraction beam dumps (MARS15).
Consider marble on most collimators
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 4
Water and Liquid Sodium Dumps
T1/2 (yr) Sat. time (yrs=5000hr)
TBq TBq
3H 12.35 93 146 258
7Be 0.146 1.1 60 63
Water Sodium
TBq TBq3H 237 202
7Be 58 1922Na - 442
Verification for 250-GeV 12-MW e-beam on water dump (R=0.6m, L=10m)
TESLA TDR MARS15
250-GeV 11-MW e-beam on water and sodium dumps (MARS15)
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 5
Muon Spoilers in BDS Tunnel
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 6
BDS Background in SiD
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 7
IP & BDS Backgrounds in SiD
STRUCT + MARS15 + SLIC+ LCDD + PYTHIA
HCAL Endcap hit rates:
Red – BDS (no spoilers)Green – BDS (w/spoilers)Blue – e+e- events
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 8
Bent Crystal Experiment at ATF2
• On June 1, 2006, ATF-TB has accepted the proposal to set up a bent crystal at ATF beam dump
• They want us to estimate radiation when the beam hits our setup from the radiation safety point of view
• We need an estimate by next ATF-IB meeting in Vancouver in July
• Simulations will be performed with MARS15 at Fermilab and (hopefully) with GEANT4 at Hiroshima University
• KEK and Hiroshima team will come to Fermilab for crystal collimation
experiments at Tevatron in November-December
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 9
Beam Dump and Beam Loss in SMTF Test Facility
750-MeV 45-kW e-beam on dump
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 10
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 11
Cryomodule MARS15 Model
Nb(cavity)
mu-metal
Ti
SS(Stainless Steel)
SSSS
SS Al
Al
Si(thermister)
Si(thermister)
Al
Al
Carbon Steel
He-gas
He-Liquid
thermal shield
thermal shield
Radiation loads totemperaturesensors
Ductstreamingthroughwaveguidesin Linac
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 12
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 13
Cryomodule Geometry in MARS15
Nb(cavity)
mu- metal
SS(Stainless Steel)
SS
AlAlCarbon Steel
He-gas
mu- metal
Ti
Nb(cavity)
Test calculation 100 MeV electron 1E12 e/sec (16W) 1mrad uniform loss inside cavity
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 14
Prompt Dose Rate
Prompt Dose [mSv/ h] Prompt Dose [mSv/ h]
Side View(Integrated over diameter length)
Front View(Integrated over 12 m long)
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 15
Power Density , Energy deposition [Gy/ sec, mW/ g]
Si(thermister)
Si(thermister)
Absorbed Dose Rates in Thermisters
Up to 0.2 Gy/s,with 100-MeV16-W beam loss
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 16
Needed Parameters
Source TermPower?Distributions of energy, angle, location?
for - Beam halo - Dark Current Fowler-Nordheim Model (TESLA Report 2003-10) Simplified source term?
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 17
Shielding and Maze Design for NIUILC Beam Diagnostics Laboratory
• R&D on charged particle beam diagnostics for ILC (ILCTA at Fermilab, AWA at Argonne), FEL, proton driver
• Ultimate goal: Operate a low-average-current, 6-20 MeV racetrack-microtron accelerator to drive coherent
light source
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 18
Basic Beamline Design atBeam Diagnostic Laboratory
<Beam Parameter>
6~20 MeV10 A in peak6uA in average
Bunch 0.44 nC 10-20ps(total) 2.856 GHzPulse 1 Hz
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 19
Shielding Structure at BDL
?
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 20
MARS15 Geometry
2 feet thick concrete Shiedling
Al beam dumpwith Lead Shielding
Electron Gun
Beam line
20 MeV6 uAelectron beam
20 MeV6 uAelectron beam
Lead Shielding
Al beam stopper1cm thick
1'
2' diam
1'
ILC BDS – June 27, 2006 Radiation Studies - N. Mokhov, N. Nakao, S. Striganov 21
Prompt Dose with MARS15
P rompt D ose [mrem/ h]
Side view
100
DOE regulation:
Prompt Dose Rate < 1mrem/hr - Outside concrete shielding wall - Exit of Maze
Should Review dump & wall design
Analytical approach + MARS15
50
T op view
10
10
100
50
Top Related