diff --git a/flamedisx/nest/config/lz_WS2024.ini b/flamedisx/nest/config/lz_WS2024.ini
index ca2a1aa3..038563d3 100644
--- a/flamedisx/nest/config/lz_WS2024.ini
+++ b/flamedisx/nest/config/lz_WS2024.ini
@@ -7,12 +7,11 @@ drift_field_config = 96.5 ; V/cm
 gas_field_config = 8.301178 ; kV/cm
 
 radius_config = 72.8 ; cm not sure what to do here
-;grab from core cuts
-dt_min_config = 71000. ; ns
-dt_max_config = 1050000. ; ns
 
 z_topDrift_config = 146.1 ; cm
 dt_cntr_config = 517927 ; ns old: 462500.
+gate_config = 145.6 ; cm
+cathode_config = 0. ; cm
 
 g1_config = 0.1122 ; MADE FLOATABLE INSTEAD
 elife_config = 9000000. ; ns
@@ -35,9 +34,6 @@ s2_thr_config = 570.58 ;
 S1_noise_config = 0.083 ; see the note
 S2_noise_config = 0.
 
-
-
-
 ; Selection parameters
 S1_min_config = 0. ; REDUNDANT FOR THIS SOURCE
 S1_max_config = 0. ; REDUNDANT FOR THIS SOURCE
diff --git a/flamedisx/nest/lxe_sources.py b/flamedisx/nest/lxe_sources.py
index 6f77a4a0..e787ec4e 100644
--- a/flamedisx/nest/lxe_sources.py
+++ b/flamedisx/nest/lxe_sources.py
@@ -52,13 +52,8 @@ def __init__(self, *args, detector='default', **kwargs):
         # energy_spectrum.py
         self.radius = config.getfloat('NEST', 'radius_config')
         self.z_topDrift = config.getfloat('NEST', 'z_topDrift_config')
-        #TO DO-Derive these from the drift map? (invert it and centre?)
-        self.z_top = self.derive_z({'r':0,'drift_time': config.getfloat('NEST', 'dt_min_config')})
-        # self.z_topDrift - self.drift_velocity * \
-        #     config.getfloat('NEST', 'dt_min_config')
-        self.z_bottom = self.derive_z({'r':0,'drift_time': config.getfloat('NEST', 'dt_max_config')})
-        # self.z_topDrift - self.drift_velocity * \
-        #     config.getfloat('NEST', 'dt_max_config')
+        self.z_top = config.getfloat('NEST', 'gate_config')
+        self.z_bottom = config.getfloat('NEST', 'cathode_config')
 
         # detection.py / pe_detection.py / double_pe.py / final_signals.py
         self.g1 = config.getfloat('NEST', 'g1_config')