BLM Internal Workshop

Wednesday Apr 23, 2025, 9:00 AM → 4:00 PM US/Eastern

L102 (CEBAF Center)

Welcome!

During the relatively low power run from 1 September 2023 through 31 May 2024 there were 5009 BLM (beam loss monitor) trips, about one eighth of the total FSD trips.  While the machine was down for only 24 hours due to these trips, collaborations typically cut 45-60 seconds per trip, so 60-85 hours of physics was lost.  It is not clear how many of these BLM trips would have resulted in machine damage, aka how many were false positives.  The workshop will establish a common basis of knowledge about the system and explore possible paths forward.  

An optional Zoom link is available --> https://jlab-org.zoomgov.com/j/1600078125

9:00 AM Workshop Introduction (Eduard Pozdeyev)

1 Introduction to CEBAF BLM System

Requirements, design, implementation (cover both protection and diagnostics BLMs)

Speaker: Brian Freeman

BLM_System_Introduction.pdf

BLM_System_Introduction.pptx

2 Beam Loss Mechanisms

"1. Beam loss mechanism contributing to downtime
a. What we know (anlaysis, evidence)
b. What we do not know
c. What we need to know
2. Specific beam transport issues contributing to beam losses"

Speaker: Yves Roblin

cebafbeamloss-modeling-blmworkshop04232025.pptx

3 Specifications and BLM Calibration Procedure

1. BLM system specifications
   a. Are specifications appropriate to prevent damage, activation
   b. Do we understand impact of losses (damage, activation) sufficiently
   well
2. Calibration procedure
   a. Are our calibration procedures appropriate (not too lax or
   conservative)"

Speaker: Jerry Kowall

BLM Internal Workshop - Specs & Calibration JKowal 20250423.pptx

10:30 AM Discussion

10:50 AM Break

4 Analysis of BLM System Performance

1. Identify and evaluate performance gaps (with goals to protect CEBAF
   and allow tuning)
2. Does the BLM MPS system perform as expected?
   a. Is it overprotecting, under protecting, or works just right?
   b. Do we have unnecessary trips what we think are unwarranted
   c. Do we have accelerator unexpected/unwarranted damages
   d. Do we have unexpected activation of the accelerator
3. Does the system design of the system allow for efficient tuning
4. Are there deficiencies in the system layout or/and design that limit
   its performance?"

Speaker: Katheryne Price

BLM_system_performance.pdf

11:40 AM Discussion

12:00 PM Lunch (On Your Own)

5 BLM System Maintainability and Obsolescence

1. Are there issues with BLM system maintainability. How can maintenance
   be improved if necessary
2. What are obsolescence issues that need to be addressed"

Speaker: Roger Araiza

BLM System Maintainability and Obsolencense Presentation 1.pptm

6 Opportunities for Near-Term Improvements

Identify and evaluate possible near-term, incremental improvements

Speaker: Jay Benesch (JLab)

BLM_rec_2025.ods

possible_BLM_improvements.pdf

RadSurveys.pdf

1:50 PM Discussion

2:10 PM Break

7 Opportunities for Long Term Improvements, Ops Perspective

Speaker: Jay Benesch (JLab)

LCLSII_2017_BLMs_th1ab2_talk.pdf

PhysRevAccelBeams.23.082802_SLAC_fiber.pdf

2:35 PM Discussion

8 Upgrade Options (Presenters)

Present possible upgrade options for the BLM system, 15 min each: J. Benesch, P. Degtiarenko, …

IDX_BLM - PDegtiarenko.pdf

3:30 PM Discussion