Change photoionization file format to avoid pkl (#411)

* Photoionization file

* Photoionization file 2

* Minor change

---------

Co-authored-by: Diego Ramírez García <diego.ramirez@physik.uni-freiburg.de>

wfsim/core/afterpulse.py

@@ -33,8 +33,9 @@ def electron_afterpulse(self, signal_pulse, signal_pulse_instruction):
         delaytime_pmf_hist = self.resource.uniform_to_ele_ap
 
         # To save calculation we first find out how many photon will give rise ap
+        # Number of "created electrons" in liquid xenon
         n_electron = np.random.poisson(delaytime_pmf_hist.n
-                                       * len(signal_pulse._photon_timings)
+                                       * len(signal_pulse._photon_timings) # Number of "detected" photons
                                        * self.config['photoionization_modifier'])
 
         ap_delay = delaytime_pmf_hist.get_random(n_electron)

wfsim/load_resource.py

@@ -96,7 +96,6 @@ def config_to_file(config):
                 "s2_luminescence_gg": "garfield_timing_map_gas_gap_sr0.npy",
                 'gas_gap_map': 'gas_gap_warping_map_January_2021.pkl',
                 'garfield_gas_gap_map': 'garfield_gas_gap_map_sr0.json',
-                'ele_ap_pdfs': 'x1t_se_afterpulse_delaytime.pkl.gz',
                 'noise_file': 'x1t_noise_170203_0850_00_small.npz',
                 'fdc_3d': 'XnT_3D_FDC_xyt_dummy_all_zeros_v0.1.json.gz',
                 'field_dependencies_map': '',
@@ -359,7 +358,7 @@ def _rz_map(z, xy, **kwargs):
 
             # Electron After Pulses
             if config.get('enable_electron_afterpulses', False):
-                self.uniform_to_ele_ap = straxen.get_resource(files['ele_ap_pdfs'], fmt='pkl.gz')
+                self.uniform_to_ele_ap = straxen.get_resource(config.get('ele_ap_pdfs', ''), fmt='dill')
 
             # S2 photons timing optical propagation delays
             if config.get('s2_time_spline', False):