Test Beams Carol Johnstone Accelerator Science Working Group
Test Beams Carol Johnstone Accelerator Science Working Group Fermilab April 21, 2017
Test Beams for HEP Out reach • The HL-LHC accelerator and detector upgrades are the highest US priority according to P 5 • The availability of precision mixed beams of hadrons and leptons with a wide range of calibrated energies and beam properties are essential for testing and qualification of components for HL-LHC, DUNE and other HEP initiatives. • CERN will switch off their test beams at the end of 2018 for two years. This period coincides with the launching of many detector components in particular for the HL-LHC, but also prototypes for other planned HEP experiments including DUNE. • Outside of CERN, only a few test beam facilities are appropriate. These include the DESY electron beam, limited to < 10 Ge. V, SLAC with 25 Ge. V electrons, and the Fermilab Test Beam Facility (FTBF) • Calorimeters, especially new types, are being designed to detect both electromagnetic and hadronic energy deposition – typical of collider jets. It is not sufficient to study just EM calorimetry therefore electron facilities cannot support most of the required work • The FTBF has the only mixed test beams outside of CERN: the FTBF will be crucial to meet critical-path HEP milestones and schedules including • Testing and qualification of HL-LHC detector components • Potentially proto. DUNE
Test Beams Supported Experiments and R&D CERN: SPS Test Beams Out reach TOTEM at CERN • Users: 2000/year at SPS test beams • Experiments and Detector R&D included • • High-Luminosity LHC (ATLAS and CMS)* proto. DUNE NA 61 Eu. DET (detectors for ILC) DREAM, CALICE calorimeter prototypes SC-RP, TOTEM CERN-EU, high-energy reference field (CERF) facility: dosimetry at commercial flight altitudes and in space CMS Prototype Sensor + PCB Module at FTBF Fermilab: MTEST and MCENTER • Users: 31 institutions; 6 countries; 261 on site in 2016 Ne ut 16 FTBF experiments in 2016 11 publications from FTBF experiments; 4 in progress D Co l No lider n. L HC llid LH er C High-Luminosity LHC (ATLAS and CMS)* s. PHENIX calorimeter for RHIC; also e. RHIC Detector R&D for g-2 and Mu 2 e LAr. IAT ( Boo. NE, SBND, DUNE, ICARUS) General detector R&D CALICE Co • • • Lar. IAT TPC, FTBF on Mu • Experiments and Detector R&D included rino R& • • FTBF Committee Report, 2016 * The HL-LHC accelerator and detector upgrades are the highest US priority according to P 5
CERN (SPS) and Fermilab Test Beams Overview CERN SPS Test Beams • 2 primary, 4 secondary lines (wobbled between two targets • Supported running modes: Beamline Particles H 2 protons, electrons ( decay), heavy ions, muons Momentum Range and Bite 10 – 360 Ge. V/c CMS, NA 61 ± 0. 05 -2. 0% p/p H 4 (generally opposite polarity from H 2) hadrons, electrons, muons, heavy ions 10 – 360 Ge. V/c H 6 Medium-energy hadrons, tertiary beams 10 – 205 Ge. V/c hadrons, electrons, muons 10 – 400 Ge. V/c H 8 Users DUNE prototype, CMS ± 0. 05 -1. 4% p/p Eu. DET, ATLAS, CERF, SC-RP ± 0. 1 -1. 5% p/p DREAM, LHC, CALICE, ATLAS, TOTEM Fermilab Test Beams: MTEST and MCENTER • Mixed secondary beams range from low to medium energies, depending on the target used (MT 1 or MT 4) • Supported running modes: • 120 Ge. V primary protons • 8 -60 Ge. V pions and some protons (MT 1 target) • 1 -32 Ge. V pions, electrons, kaons, or broadband muons (MT 4 target) • Electrons can be eliminated with a lead absorber • “Pure” electron beam cannot be implemented in existing lines • 0. 2 -1 Ge. V pions, protons, kaons (tertiary target, Mcenter) • Neutrino Muon: High-intensity Future Test Beam? • 1013 p/spill capability (vs. 1011 on the MT 4 target) Out reach
Fermilab Test Beams Needed Upgrades FTBF Committee Report, Nov. 2016: Recommendations Out reach T MTES • Oversubscribed. Present facility is operating near capacity with 261 users; projection is that the facility cannot accommodate the majority of CERN test beam users during the shutdown. • High Energy Reach. Experimenters have requested electron and hadron energies above 25 Ge. V with electrons the most problematic. • For higher-energy electrons (>30 Ge. V), the extracted slow-spill intensity from the MI must be increased to compensate for the lower primary beam energy and lower production cross section (as compared with the SPS). • Likely involves rarer production processes – two orders of magnitude lower • Only a few hundred/spill required for detectors • The MI is capable of delivering 1013 protons/spill, about a factor of 5 higher than the SPS. • The meson complex is presently limited to 2 x 1011 protons/spill on target. • The intensity at the MT 1 target location can be increased given the well shielded M 02 enclosure. (MT 4 target will remain intensity limited). • Low Energies. Experimenters have requested a large dynamic range which is problematic as magnets have hysteresis and effects which become significant for low energies • Collaboration with an electron facility (KEK) is important to plan a comprehensive HEP testing program to include crucial low-energy precision electron beams. • Lower Momentum Bite. The momentum bite is about an order of magnitude larger than Cerenkov data >30 Ge. V positrons! CERN (~2% vs 0. 2%). • Momentum bite is presently constrained by the collective enclosure geometry and limited length available for the beamline. • A redesign or new beamline is required to lower the momentum bite • Increased electron beam purity. Increased purity of electron beams requires speciallydesigned optical chicanes or separators to separate different particle species. • Difficult in the current meson test beamlines and enclosures. MCENTER HOWEVER WE HAVE A NEW IDEA FOR SECONDARY/TERTIARY TEST BEAMS
Innovations in Test Beams Primary Beam Requirements: • Full MI intensity or 1013 Protons on Target per spill • • M 01 -3 enclosures New target material for secondary emittance control (Be) • Increased particle density in a given secondary phase space Secondary Beam: • Optics design criteria • • Optimized collection efficiency Large dynamic range in momentum selection; high-intensity primary beam absorber Refocus after momentum selection on tertiary target for emittance control Tertiary target optimized for d. E/dx species-dependent energy loss and emittance • Momentum bite optimized for species selection Tertiary Beam: • Optics design criteria • • Selectable particle species including electrons and positrons with high purity • Dependent on d. E/dx of tertiary target, tertiary phase space, and enclosure geometry • Dipoles/enclosure direction change required after tertiary target • Mitigates backgrounds Large dynamic range in momentum; secondary beam absorber <1% or higher variable momentum bite Refocus after momentum selection on experimental areas Out reach
Work in Progress on Test Beams • MT 1 target: • Preliminary intensity calculations indicate 1013 or higher capability on present Al target • Shielding assessment allows for higher intensities in this enclosure • Study of rare production processes needed for higher energy leptons in GEANT 4 and G 4 BEAMLINE • Primary target design concepts and optimization • Beam measurements planned prior to shutdown Out reach Co l No lider n. L HC • Beamlines: • • Efficient secondary collection and transport optics to tertiary target Efficient tertiary collection and beam transport Magnets and power supplies (should be sufficient inventory) Access and labor required for installations • Instrumentation. • New instrumentation for ultra-low intensity and energy, pure-species tertiary beams T • Upgrades can be ready for 2018 shutdown and commissioned by 2019 CERN shutdown MCENTER • MTEST can support • High-intensity primary beam target and absorber in M 01 -2 • Secondary target possible in M 03 • Directional change (dipoles) in M 03 for species selection • Longer beamline for tertiary beam • Small momentum bite will still be challenging – there are ideas MTES • Preliminary (very) assessment
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