[Sns_ppu_group] Fw: Critical test validates 1.7 MW at SNS

[Christine Fragapane]

FYI

________________________________
From: Ed Daly <edaly at jlab.org>
Sent: Thursday, April 9, 2020 1:46 PM
To: Christine Fragapane <chummel at jlab.org>
Subject: Fw: Critical test validates 1.7 MW at SNS

Dear Christine,
Please forward to the PPU team.
Thanks,
Ed

________________________________
From: Champion, Mark <championms at ornl.gov>
Sent: Wednesday, April 8, 2020 1:04 PM
To: Ed Daly <edaly at jlab.org>
Subject: [EXTERNAL] FW: Critical test validates 1.7 MW at SNS

Ed,

Here’s the announcement in case you didn’t receive it already.

Mark

From: "Evans, A. Jeanine" <evansaj at ornl.gov>
Date: Monday, April 6, 2020 at 12:38 PM
To: NScD-Staff-Dist <nscd-staff-dist at ornl.gov>
Subject: Critical test validates 1.7 MW at SNS





Critical test to validate 1.7 MW power level successfully executed at the SNS



Proton Power Upgrade (PPU)

A beam power of 1.7 MW is a Key Performance Parameter (KPP) for the SNS Proton Power Upgrade (PPU) project. The current PPU schedule plans to begin increasing the beam power on target above 1.4 MW in 2022 and reach reliable 1.7 MW operation in late 2023. Current target designs have proven to be reliable up to a beam power of 1.4 MW with helium gas injection.



After each target installation, at the beginning of each run, measurements of target strain both without and with helium gas injection are done. With these data, a strain reduction factor ((•no gas – •with gas)/•no gas) can be calculated to show the effect of helium gas injection.  Analysis of strain data from the last target (T24) indicate that the strain reduction factors are 40% or higher and that strain reduction factors are near constant at beam powers higher than 1 MW up to 1.4 MW.  Since modifications to target designs can take years to implement it is important to extend measurements above 1.4 MW up to 1.7 MW.



Testing Plan

The plan for testing 1.7 MW beam consisted of two parts. First, at the end of the last run period, we verified that the linear accelerator and ring are capable of delivering the higher power beam.  Second, at the start of the current run period, we measured the strain with the new target (T25) up to 1.7 MW.



1.7 MW Accelerator Performance Verification in February 2020

In order to achieve 1.7 MW, the beam current was increased by 20% by raising the RFQ field. For the test, , the repetition rate was decreased from 60 Hz to 5 Hz to reduce the probability of potential damage to the RFQ.



The increased beam loading tests, including studies of beam behavior in the accumulator ring, at a peak current equivalent to 1.7 MW proved there are no major issues preventing reliable accelerator operation at that power level.



1.7 MW Strain Measurements in April 2020

The overall goal of the 1.7 MW test on Friday, April 3, was to verify whether the strain reduction factors remain nearly constant at beam powers up to 1.7 MW. Strain measurements were performed at variable target beam powers both without and with helium gas injection. Preliminary data analysis shows that the strain reduction factors are nearly constant for beam powers greater than 1 MW up to 1.7 MW.  More detailed data analysis is in progress, but data trends are promising.



Executive Summary

  *   The accelerator is capable of reliably delivering beam power on target up to 1.7 MW.
  *   The gas injection strain reduction factors are nearly constant for beam powers greater up to 1.7 MW.









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