WEBVTT 00:01.070 --> 00:01.870 Good day everyone. 00:02.150 --> 00:06.830 My name is Meghana Patil and I'm a PhD student at IPPT in KIT and I 00:06.830 --> 00:08.510 work on beam diagnostics for CARA. 00:09.110 --> 00:12.230 Today in my poster I will be talking about CALYPSO and its application 00:12.230 --> 00:13.670 for beam and spectral analysis. 00:14.630 --> 00:18.470 CARA is an accelerator test facility located at KIT with an operation 00:18.470 --> 00:21.290 energy range from 500 MeV to 2.5 GeV. 00:21.890 --> 00:24.730 One of the operation modes is low alpha mode where the momentum 00:24.730 --> 00:28.810 compaction factor is reduced resulting in short punctures which gives 00:28.810 --> 00:32.830 rise to a phenomenon called as micro-puncturing instability and this 00:32.830 --> 00:34.710 is extensively studied in our facility. 00:36.230 --> 00:39.930 To understand such complex beam dynamics which occur in very short 00:39.930 --> 00:42.550 time scales fast real-time measurements are needed. 00:42.870 --> 00:46.650 Hence we need detectors which can have megahertz repetition rate, high 00:46.650 --> 00:50.570 spatial resolution, wide spectral sensitivity, capable of long 00:50.570 --> 00:54.010 acquisition times and also capable of synchronizing with experimental 00:54.010 --> 00:55.830 setup and other diagnostic tools. 00:56.990 --> 00:58.830 One such tool is CALYPSO. 00:59.330 --> 01:02.390 So let me just briefly explain the building blocks of CALYPSO. 01:02.790 --> 01:06.630 We have a microstrip sensor based on a conductor which is connected to 01:06.630 --> 01:08.770 an ASIC operating at megaframe per second. 01:09.250 --> 01:13.630 When fully populated there are 64 ADC channels operating at 125 mega 01:13.630 --> 01:14.510 samples per second. 01:15.010 --> 01:18.530 We have external clock inputs available for synchronizing with the 01:18.530 --> 01:19.430 experimental setup. 01:19.790 --> 01:23.630 We have an on-chip programmable PLL which is used to distribute the 01:23.630 --> 01:25.050 clocks based on user requirement. 01:25.570 --> 01:29.290 This entire detector is connected to an FPGA based standalone card or 01:29.290 --> 01:31.250 a micro TCA based DAQ system. 01:32.850 --> 01:36.010 Let me get in detail about the different kinds of sensors used on 01:36.010 --> 01:36.350 CALYPSO. 01:36.690 --> 01:40.250 The most commonly used is a microstrip silicon sensor designed at KIT 01:40.250 --> 01:41.950 with several topologies and sizes. 01:42.810 --> 01:46.670 There is an anti-reflecting coating applied to them in order to 01:46.670 --> 01:50.590 improve their quantum efficiency in the near ultraviolet visible and 01:50.590 --> 01:51.690 near infrared range. 01:53.090 --> 01:57.730 Silicon is sensitive from 350 nanometer to 1050 nanometer but beyond 01:57.730 --> 01:59.370 this it is basically transparent. 02:00.110 --> 02:03.050 Hence we have to use other semiconductor based sensors like indium 02:03.050 --> 02:05.630 gallium arsenide which is sensitive to 2000 nanometer. 02:06.550 --> 02:10.190 Lead sulfide which is sensitive up to 3300 nanometer and lead selenide 02:10.190 --> 02:12.130 which is sensitive up to 5000 nanometer. 02:12.550 --> 02:15.270 Now let us see the complete data acquisition flow which is currently 02:15.270 --> 02:16.350 implemented in CARA. 02:17.410 --> 02:21.210 The CALYPSO card is connected to the FPGA based DAQ system with a 02:21.210 --> 02:22.370 standard FMC connector. 02:22.970 --> 02:24.890 This FPGA card has two main jobs. 02:25.030 --> 02:28.790 One to provide control to the various circuit elements on CALYPSO and 02:28.790 --> 02:32.190 the second is to transfer the incoming data into a CPU or GPU for 02:32.190 --> 02:34.150 further processing via PISA express. 02:34.710 --> 02:38.610 The newest version of this standalone FPGA card can also be connected 02:38.610 --> 02:41.330 to the micro TCA system via optical fiber. 02:42.190 --> 02:45.410 Now I will give a brief overview of the applications of CALYPSO and 02:45.410 --> 02:46.690 where it is currently used. 02:47.330 --> 02:51.450 At CARA here in we use it for electro-optical spectral decoding as a 02:51.450 --> 02:54.030 way to measure the longitudinal profile of the electron beam. 02:54.610 --> 02:58.230 Here you can see a current setup with the yttrium laser at a 02:58.230 --> 02:59.890 wavelength of 1050 nanometer. 03:00.710 --> 03:03.770 The coulomb field of the electron bunch is encoded in the chirp laser 03:03.770 --> 03:05.750 pulses at the gallium phosphide eo crystal. 03:06.410 --> 03:09.450 The entire system is synchronized to the repetition rate of the 03:09.450 --> 03:11.430 storage ring which is 2.7 megahertz. 03:12.190 --> 03:14.690 Hence in the current setup we operate in a single shot mode. 03:16.190 --> 03:20.250 The energy spread of the electron bunch is also a crucial parameter in 03:20.250 --> 03:21.230 micro bunching studies. 03:21.750 --> 03:24.850 It can be measured by measuring the horizontal bunch profile of the 03:24.850 --> 03:29.130 incoherent synchrotron radiation as it is coupled to the energy spread 03:29.130 --> 03:31.070 in the dispersive sections of the accelerator. 03:32.050 --> 03:36.070 This radiation emitted at the visible light diagnostic port of CARA is 03:36.070 --> 03:40.030 in the visible spectral range from 400 nanometer to 700 nanometer. 03:42.030 --> 03:46.190 The terahertz diagnostics are also crucial for micro bunching studies. 03:46.410 --> 03:49.590 Here we are currently employing CAPTCHA which is a picosecond pulse 03:49.590 --> 03:50.310 sampling system. 03:50.830 --> 03:53.870 And now we are in the process of commissioning a far-field eo setup 03:53.870 --> 03:57.430 with CALIPSO to study and investigate the terahertz radiation emitted 03:57.430 --> 03:58.730 at CARA. 03:59.650 --> 04:03.270 This is a result from the longitudinal bunch diagnostic measurements 04:03.270 --> 04:04.330 done using CALIPSO. 04:04.650 --> 04:08.970 This is the evolution of the longitudinal bunch size over time and 04:08.970 --> 04:12.050 when backfilter propagation is applied, the phase space density of the 04:12.050 --> 04:13.670 electron bunch can be reconstructed. 04:14.250 --> 04:17.790 More details on this can be found in the poster from Godron Neos. 04:18.370 --> 04:21.210 This is the result from the horizontal bunch diagnostics. 04:22.510 --> 04:26.570 This data corresponds to the horizontal bunch position and the size 04:26.570 --> 04:31.230 respectively acquired or processed from the raw data acquired from 04:31.230 --> 04:31.630 CALIPSO. 04:32.350 --> 04:36.750 This data over here corresponds to a spectrogram which was constructed 04:36.750 --> 04:39.590 using the terahertz signal sampled using CAPTCHA. 04:40.290 --> 04:43.570 More details on this can be found in the poster or talk from Miriam 04:43.570 --> 04:44.030 Rossi. 04:45.430 --> 04:49.990 And also the commissioning of CALIPSO at the far-field setup, the 04:49.990 --> 04:53.090 details about this can be found in the poster from Christina Wittman. 04:53.550 --> 04:57.770 And in an overall details about all these can be found also in my 04:57.770 --> 04:58.030 talk. 04:58.390 --> 04:59.250 So please visit. 04:59.590 --> 05:00.010 Thank you.