Pellet models in TRANSP

Pellet injection events are specified through the namelist.

TRANSP namelist:

KPELLET: pellet ablation model idenfitier [hydrogenic 0-5, impurity 10-11]

NPEL: number of pellet events
TPEL: list of NPEL pellet event times in ascending order of time
APEL: species (atomic weight) of injected pellet (e.g. 2.0 for deuterium); enter a number for each pellet. APEL values must be drawn from the following sets:

{1.0, 2.0, 3.0} -- isotopes of Hydrogen
{6.0, 7.0} -- isotopes of Lithium

Helium pellets are not allowed in the model.


To assign a 2nd specie to the j'th pellet in a run, set:

FPEL2(j): fraction of pellet which is the 2nd specie. APEL2(j): Atomic weight of 2nd specie. Values legal for APEL are legal for APEL2 as well. APEL(j) and APEL2(j) should be distinct.

Note: current pellet ablation module does not support multi-specie pellets. It will eventually be reintroduced.

TRDAT namelist:

If a TRANSP run includes pellet injection then, for each pellet, a "hazard time interval" should be input to TRDAT to specify the time range about the pellet injection time during which none of the UFILE input data should be trusted. TRDAT will extrapolate all UFILE data forward/back to the pellet time(s) based on data values and time derivatives at the endpoints of the hazard interval(s)-- except as modified, cf section on event_handling.
In the TRDAT namelist,
TPELDA(1,J): LAST VALID TIME for input UFILE data PRECEDING injection of the Jth PELLET
TPELDA(2,J): FIRST VALID TIME for input UFILE data FOLLOWING injection of the Jth PELLET


  1. The time interval TPELDA(1,J) to TPELDA(2,J) must enclose an actual pellet event as specified in the TRANSP namelist. See TRANSP namelist info on PELLETS.
  2. The hazard intervals must be bounded away from the start and stop times of the TRANSP analysis (TRANSP namelist variables TINIT, FTIME). These intervals may not overlap.
  3. TPELDA controls do not have to be set for ablation simulations; they are only needed if there is an actual pellet event in the data.
  4. TPELDA entries for "pseudo" pellets with NMPELA(j)=2 are ignored.

  1. W.A.Houlberg, S.L.Milora, S.E.Attenberger, Nucl Fusion 28 (1988) 595
  2. S.L.Milora, ORNL/TM-8616 (1983)
  3. W.A.Houlberg, M.A.Iskra, H.C.Howe, S.E.Attenberger, ORNL/TM-6549 (1979)
  4. W.A.Houlberg, L.R.Baylor 6/2004
  5. W.A.Houlberg, F90 free format 8/2004
  6. P.B. Parks, L.R. Baylor, Phys. Rev. Lett. 8, 1968 (2005)