Develop Radiation Hard Beam Monitor and Muon Spectroscopy by using - - PowerPoint PPT Presentation

Katsuya Yonehara CPAD Workshop 12/08/2019

Develop Radiation Hard Beam Monitor and Muon Spectroscopy by using Machine Learning for Intense Neutrino Target System

• NuMI-AIP (Neutrinos at the Main Injector – Accelerator Improvement Plan)

– Upgrade existing Fermilab accelerator complex with the same footprint to increase proton beam intensity on the NuMI target from 780 kW to > 900 kW – Machine operation starts from 2020

• LBNF (Long Baseline Neutrino Facility)

– Apply PIP-II SRF Linear Accelerator to send 1.2 MW beam to the LBNF target – Machine operation will start from 2029 – Extend to PIP-III SRF Linac to reach 2.4 MW beam power – Operation year TBD

Fermilab Intensity Upgrade Plan

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Fermilab Accelerator Complex

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• Tolerance of the target parameter at LBNF

– Tighter than NuMI

• Beam monitor is a real-time (spill-by-spill) detector to

check quality of multi-MW target system

– High reliability and long lifetime (rad hard) required

Beam Monitor for multi-MW Target System

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Develop Rad-Hard Beam Monitor System

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Hadron monitor (0.8x0.8 m2, 7x7 pixels) Muon monitor (2x2 m2, 9x9 pixels)

NuMI Target system

Thermocouple detector (3+3 Be wires)

Multi-pixel ionization chamber

• Target beam elements were occasionally displaced or broken

by various incidents

– Radiation damage, thermal expansion, thermal shock, water leak, Helium gas leak, etc

• Beam based alignment permits us to find baffle, target and

horn positions w.r.t. the BPM coordinate by using beam monitors

• Position resolution less than 0.2 mm is achieved

Beam Monitor for Beam Based Alignment

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• Beam position and angle are measured by two bpms
• Beam position on target is observed by thermocouple sensor
• Scan requires a special beam condition, but it takes less than hour

Horn 1 Horn 2

Hadron Monitor

Layout of beam based alignment

• Develop rad-hard ionization chamber
• Observed signal gain change by varying He gas quality

– Calibration chamber can calibrate the gain change due to gas quality, but this is not the perfect solution – Apply a new gas system

• Density flow control by using PLC
• Add bubbler on the outlet of HM to avoid backflow
• Use a radiation hard material

– Apply radiation hard ceramics for insulator and cable

• Optimize the dimension of monitor system

– Beam profile simulation – Space charge simulation

Upgrade Beam Monitor for 1-MW operation

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Particle Tracking in Simulation

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Target Horn 1 Horn 2

Horn 1 Horn 2

Shows Aberration of horns Beam profile on hadron monitor

Alternate Hadron Monitor

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• RF beam detector
• Conceptually new rad-hard beam detector
• Apply RF field to measure the amount of ionization gas plasma which is

proportional to the intensity of charged particles passing through a RF cavity by measuring gas permittivity change 𝜁 = 𝜁! + 𝑗𝜁"

• Proof-of-principle test was carried out by using the Main Injector 120 GeV

proton beam

2.4 GHz RF test cavity Fabricated in MI-40 abort room

Charged particles

Cavity body Waveguide

0.000000 5.×10-6 0.000010 0.000015 20 40 60 80 100 120 Time (s) Voltage in cavity (V)

Beam is turned on Beam is turned off Five peaks during the beam on shows the gap of six MI beam batches

• Beam intensity = 1.3e13
• Detector filled with ambient air

FY19

Linearity of RF beam detector

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1 2 3 4 0.000 0.005 0.010 0.015 0.020 Beam Intensity (1e12 protons/spill) RF power consumption (J)

𝑞 = 𝑊

# 𝑊 # − 𝑊 𝑢

𝑆

1-atm N2, V0 = 120 V 2

• a

t m d r y a i r , V0 = 1 2 V 1

• a

t m H e , V0 = 1 2 V 2-atm N2, V0 = 60 V

FY19

• Three monitor receive different energy muons
• Similar structure as Hadron monitor

Muon Monitor

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Muon Monitor 1 signal

Systematic measurement

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MM1 MM2 Horizontal scan

Strong linear correlation between primary proton beam and muon beam centroid on Muon Monitors

FY19 FY19

MC simulation MC simulation

MM2 shows opposite slope from MM1 due to Aberration of horns

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• Individual pixel sees different muon spectrum
• X1 & X9, X2 & X8, X3 & X7, X4 & X6 shows similar shape as expected

Pion/Muon Spectroscopy

Select pixel on X-axis (y = 0) X1 X9 Magnetic horns have an analyzing power

MC simulation

Predicted Horn Current by using Machine Leaning

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Horn Current Error RMS = 0.152 kA

Training data Apply for real data 𝑆!! = 𝑔 ⃗ 𝑠"#$%, ⃗ 𝜏&!"#$, 𝐽'(&), 𝑕𝑏𝑡 𝑞𝑏𝑠𝑏𝑛𝑓𝑢𝑓𝑠

Predicted Beam centroid on Muon Monitor with ML

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Hor Error RMS = 0.15 mm

Horizontal analysis

𝐽!"#$ = 200 𝑙𝐵 180 190 195

Ver Error RMS = 0.58 mm

Vertical analysis 𝑆!! = 𝑔 ⃗ 𝑠"#$%, ⃗ 𝜏&!"#$, 𝐽'(&), 𝑕𝑏𝑡 𝑞𝑏𝑠𝑏𝑛𝑓𝑢𝑓𝑠

• Study three beam monitors

– Demonstrate that beam monitors is capable to operate the target system within the design tolerance – Introduce Machine Learning to make an automatic monitor system – Study Pion/Muon spectroscopy by using aberration of horns

• Develop rad hard ion chamber for multi-MW target

– New gas system to prevent gas contamination – Plan to simulation study to minimize space charge effect – Develop RF beam detector

• Plan more R&D to make a practical detector

Summary

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• Hadron Monitor

– Karol Lang, Marek Proga from U of Texas Austin – Joe Beleski, Jodan Bohn from Fermilab

• RF beam detector

– Rol Johnson, Mary Anne, Grigory Kazakevic from Muons Inc – Al Moretti, Dave Peterson, Adam, Dent, Kyle from Fermilab

• Muon Monitor

– Pavel Snopok, Yiding Yu from IIT – Amit Bashyal from Oregon U – Athula Wickremasinghe from Fermilab

• TSD

– Bob Zwaska, Jim Hylen, Cory Crowley, Yun He, Keith Gollwitzer, Kris Anderson, Patrick Hurh

Acknowledgement

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