diff --git a/tcl/ma15prep.config b/tcl/ma15prep.config
index 33c1719..85884ec 100644
--- a/tcl/ma15prep.config
+++ b/tcl/ma15prep.config
@@ -53,7 +53,11 @@ appendVars n2coolPar.istate|i|State|1 lc|mbar|Lambda_p|4
 makeN2cool "tcoil ta"
 catch {
   # finish hour (tomorrow morning)
-  n2coolPar time 6
+  # previous procedure:
+  #  day 1, morning: start N2, day2 morning: start fill (fast, He vessel pressurized)
+  # new procedure
+  #  day 1, morning or noon: start N2:, day2 afternoon:  slow fill overnight (self pressured He vessel)
+  n2coolPar time 12
   # target temperature for MagBot
   n2coolPar topLimit 85
   # cooling rate K / min.