High-­Intensity Multibunch Physics in the Fermilab Accelerator Complex

PI Name: 
James Amundson
PI Email: 
Allocation Program: 
Allocation Hours at ALCF: 
50 Million
Research Domain: 

The  U.S.  Fermilab  accelerator  complex  is  under  transition  to  become  the  science  facility  with  the  world’s  highest  intensity  proton  beams.  In  the  near  term,  the  complex  will  be upgraded  to  provide  700  kW  proton  beams  to  support  the  current  and  near-­future  generations of neutrino and muon experiments. In the medium term, the U.S. is dedicated to  building  a  large-­scale  long-­baseline  neutrino  experiment  to  pursue  the  physics  of  neutrino mass. An international collaboration has been formed to build the world’s largest neutrino  detector,  the  Deep  Underground  Neutrino  Experiment  (DUNE).  The  neutrino  beam  for  DUNE  will  be  provided  by  a  Long  Baseline  Neutrino  Facility  to  be  built  at Fermilab. The Fermilab PIP-­II project will upgrade the accelerator complex to provide the 1000 kW proton beam to power LBNF and DUNE. The sum of these projects are the highest priority for the future of the U.S. experimental particle physics program. The upgrades to the Fermilab accelerator complex for both 700 kW in the short term and 1000 kW in the long  term  rely  on  using  the  Fermilab  Recycler  storage  ring  to  accumulate  beam  for  acceleration in the Main Injector. The procedure to accumulate beam, called “slip-­stacking,” involves slowly combining two 80-­bunch batches of injected beam into one high intensity batch.  The  process  is  sensitive  to  the  collective  interactions  between  the  160  bunches  involved.  

This  project  supports  simulations  of  the  full  80-­on-­80  bunch  slip  stacking  process  in  the  Recycler in support of the accelerator upgrade process. This is a very large computational challenge. It will require the use of our accelerator simulation package Synergia, which has a  unique  multibunch  simulation  capability,  and  running  on  leadership-­class  computing  resources. The results of the detailed simulations will allow Fermilab to reduce both costs and risks as it moves forward to support the U.S. particle physics program.