IOTA single-electron and low-intensity studies G. Stancari for the - - PowerPoint PPT Presentation

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IOTA single-electron and low-intensity studies G. Stancari for the - - PowerPoint PPT Presentation

Mar 12, 2024 143 likes •214 views

IOTA single-electron and low-intensity studies G. Stancari for the team IOTA/FAST Group Meeting Fermilab, February 22, 2019 https://indico.fnal.gov/event/19797 Study of Thu Feb 21 (8 h) - M3L MCP-PMT signals (MCP out + 4 anodes) are good for

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SLIDE 1
  • G. Stancari for the team

IOTA/FAST Group Meeting
 Fermilab, February 22, 2019

IOTA single-electron and low-intensity studies

https://indico.fnal.gov/event/19797

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SLIDE 2

Giulio Stancari | IOTA low-intensity studies IOTA/FAST Group Meeting | Fermilab, 22 Feb 2019

Study of Thu Feb 21 (8 h)

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  • M3L MCP-PMT signals (MCP out + 4 anodes) are good for timing and

position down to ~uA intensities. Sensitivity does not reach single electrons, limited by noise (20 kHz, 400 kHz, 500 kHz, ...). Needs to be investigated and mitigated. Relied mostly on M2R camera intensities.

  • Collected data on mini-injections repeated every ~60 s. Reliably injected 0

to 3 electrons by inserting screens and regulating laser wave plate. Recorded M2R camera images of 1 stored electron.

  • Injected ~110 electrons and let intensity decay to study statistics of

individual electron loss times and to measure beam lifetime in 10-100 pA range

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SLIDE 3

Giulio Stancari | IOTA low-intensity studies IOTA/FAST Group Meeting | Fermilab, 22 Feb 2019

Photomultiplier signals with 0.48 mA circulating in IOTA

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M3L MCP-PMT out M3L MCP-PMT
 anode 1 M2L PMT anode 7.5-MHz marker 20-50 mA noise limits sensitivity (on both Heliax and RG-58 cables) Needs to be filtered or mitigated

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SLIDE 4

Giulio Stancari | IOTA low-intensity studies IOTA/FAST Group Meeting | Fermilab, 22 Feb 2019

Mini-injections

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Inserted screens in linac, tuned laser wave plate, injected every ~60 s Variation on what was done in November (no IOTA injection quad detuning). Shown reliable injection of a few electrons. Also part of our current LDRD on the feasibility of single-electron studies.

Time [s] 500 1000 1500 2000 2500 M2R camera intensity [arb. units]

0 e- 1 e- 2 e- 3 e-

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SLIDE 5

Giulio Stancari | IOTA low-intensity studies IOTA/FAST Group Meeting | Fermilab, 22 Feb 2019

Intensity and lifetime measurement down to microamps

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DCCT M2L PMT
 current M2L PMT
 counts gain x32 gain x4.5

1 μA 7.5 MHz

Two methods (to assess systematics) (1) Exponential fit (2) Derivative of smooth spline

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SLIDE 6

Giulio Stancari | IOTA low-intensity studies IOTA/FAST Group Meeting | Fermilab, 22 Feb 2019

Intensity and lifetime in 1-100 pA range (in progress)

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Two methods (to assess systematics) (1) Exponential fit (2) Max-likelihood fit of intervals between individual electron losses (steps)

P(Ti) = λ exp(−λ Ti)

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SLIDE 7

Giulio Stancari | IOTA low-intensity studies IOTA/FAST Group Meeting | Fermilab, 22 Feb 2019

Beam lifetime vs. intensity

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  • 0.005

0.010 0.020 0.050 0.100 0.200 0.500 2 4 6 8 10 Beam intensity [mA] Decay rate [%/min] 120 60 45 30 20 15 10 Lifetime [min] IOTA beam lifetime vs. intensity Data of Feb. 14, 2019, 13:30−16:02

  • N:IBEAM (DCCT)

N:IBEASL (sync−light PMT)