KPP Run Plan
- 1 12 GeV Hall C Key Performance Parameter Run Plan (Draft)
- 1.1 KPP Demonstration Items
- 1.2 Initial Beam Settings
- 1.3 Initial Spectrometer Settings
- 1.4 Initial Beam Steer-up
- 1.5 Basic Beamline, Raster, Instrumentation checkout
- 1.6 Begin Detector Checkout and Spectrometer Optics Programs
12 GeV Hall C Key Performance Parameter Run Plan (Draft)
The primary goal of this runplan is to satisfy the 5 KPP items listed below in minimal time. With that focus in mind, where practical, these goals will be accomplished as immediate side effects of broader commissioning studies to improve overall efficiency.
KPP Demonstration Items
- Detector running for 8 hours recording data from all subsystems.
- Screenshots of beam status and/or accelerator e-log entries demonstrating electron beam current and energy.
- Part of: KPP Run Plan#Initial Beam Steer Up,
- Data showing relative timing of trigger, tracking, and particle identification in detector sybsystems.
- Figures demonstrating charged-particle tracks from position-sensitive detectors.
- Particle identification plots using signals from calorimetry and Cerenkov detectors.
Initial Beam Settings
Beam Energy: > 6 GeV/c Current requirements: 5--10 uA CW Polarization: N/A
- We will NOT steer through Compton chicane
Initial Spectrometer Settings
Angle: 15 (> 7.5 degrees[*] -- Beamline Config-2) Mom: -3.0 GeV/c (nominal, not really important; lower = more rate)
Angle: 15 deg (> 10.5 degrees -- Beamline Config-2) Mom: -3.0 GeV/c
Downstream Beamline: "Config-2" - Config-2 Minimum spectrometer angles are: SHMS = 7.5 deg [*], HMS = 10.5 deg
[*] Moving SHMS below 10 degrees requires special attention to potential SHMS fringe field beam steering.
Initial Beam Steer-up
NOTE: This is an MCC driven procedure. My current understanding (March 1, 2017) is that the complete ATLis below will NOT be executed. Instead a more limited steer-up procedure will be used that is better tuned to the limited goals of the Spring 2017 Run.
Goals NOTE: NOTE MCC driven procedure * KPP 2: Establish beam to Dump with SHMS magnets at production settings.
- Beam Current: Viewer limited (Tune Beam) - Target: Empty - Raster: OFF
Procedure Excerpts (NOTE: See ATLis 16570 (Jay Benesch) for details) - SHMS magnets: OFF at beginning of procedure - Eliminate any question of beam steering due to SHMS fringe field during initial steer-up - MCC will follow their procedure to establish beam to the Hall C dump - Hall C will log snapshots of: - Beam energy, Beam current, and viewer images (if available) to satisfy KPP 2 - With Tune Beam ON, and spot visible on dump viewer: - Slowly bring up SHMS magnets to operating momentum settings. - Monitor spot image on dump viewer for unacceptable beam steering due to SHMS fringe fields. - Snapshot dump viewer images (if available) and SHMS magnet screens with SHMS magnets at operating currents when ramp complete.
Basic Beamline, Raster, Instrumentation checkout
Initial Raster checks
Goals - Establish beam to be roughly centered in beam pipe by locating it on YAG viewer just upstream of target. - Turn on Raster and verify beam profile expands as expected.
- Beam Current: Viewer limited (Tune Beam) - Target: Empty, or solid target - Raster: Off; 2mm x 2mm
Procedure - Insert YAG viewer on Hall C superharp girder - start with raster off, verify beam spot roughly centered - request raster on: 2mm x 2mm - watch beam spot on viewer and verify Raster's basic functionality - Retract viewer
Goals - Verify operation of Harp scanners w/ beam. - Establish acceptable beam profile (nominal 100--400um sigma)
- Beam Current: 5 uA CW - Target: Empty, or solid target - Raster: Off
Procedure - Take Harp swipes for all viewers on Hall C beamline - verify beam profile (nominal 100--400um sigma) on at least one scanner on Hall C upstream beamline
Target/Beam centering, Raster calibration
Goals - Establish beam position on target. * KPP 3, 4, 5: Start taking data in S/HMS, offline analysis team will start analyzing data and can begin looking for tracks, initial detector checkout.
- Beam Current: 5--10 uA CW - Target: BeO, Carbon Hole
Procedure - Note: DAQs are running and a solid target is in place - Online shift crew will proceed with program below. - Offline shift crew will focus on demonstrating KPP 3, 4, 5 using these solid target data.
- Attempt to view beam on BeO - Target: BeO - Current: 5 uA CW - Raster: OFF - Target camera: ON - Target lamp: OFF - Log camera snapshot of beam spot on BeO
- Image Carbon Hole target using Raster current pickoffs vs. raw trigger rates in SHMS and/or HMS - NOTE: If there are issues with the raster systems, this step can be skipped provided experts are confident that we know where the beam is on target (ie. good BeO snapshot) - (NOTE: This does NOT require working spectrometer Optics.) - Target: Carbon Hole - Current: 5 uA CW - Raster: 3mm x 3mm - Run DAQ on SHMS / HMS - Set prescales to ensure DAQ rate is dominated by scintillator triggers - Run Spot++ - View the Raster *Current* X vs Y plots (not BPM plots) - Locate the hole in the 2D intensity histogram Example of imaged hole: https://logbooks.jlab.org/entry/3427728 - Center Beam on Target: - Iterate until beam centered in raster pattern - Adjust beam position - Run Spot++ to view effect - Calibrate raster dimensions against (known) Carbon Hole diameter by adjusting Raster magnet settings until raster is just covering the carbon hole in the image.
Begin Detector Checkout and Spectrometer Optics Programs
Goals - KPP 3, 4, 5: Data taking in SHMS/HMS continues - Analysis team will continue debugging until KPP 3, 4, 5 can be satisfied (if not completed already) - KPP 1: This program will more than the 3 hours needed to satisfy KPP 1
Procedure Reference: Optics & Detector Working Group (Rolf Ent, Tanya Horn) * Note: DAQs are running and a solid target is in place - Online shift crew will proceed with the optics program - Offline shift crew will focus on demonstrating KPP 3, 4, 5 using these solid target data (if not established already). - If not established already, the 8 hour clock on running DAQs for KPP 1 will be satisfied during this program.