Performance of BI systems at HIE-ISOLDE Sergey Sadovich on behalf of BE-BI group and HIE-ISOLDE collaboration BI/TB - Thursday 9 Feb 2017

Outline HIE ISOLDE project Changes and development Description of the beam instrumentation Beam diagnostic boxes Performance of the devices Beam current measurement Beam profile measurement Beam emittance measurement Beam energy measurement Cavity phasing Control and readout VME card Software: FESA Summary

HIE-ISOLDE: stage 1 – stage 2A – stage N to 9.3 MeV/u for beams with A/q = 4.5 to 14.3 MeV/u for beams with A/q = 2.5 from 2.85 MeV/u 1 – 2 CM 1 – 2 HEBT lines … - 2016 3 CM (and more in stage 2+) 3 HEBT lines 2017 - …

HIE-ISOLDE – stage 2A Beam diagnostic tasks: Experimental targets Required by users and OP: Max current of RIB Intensity (transmission) Position of the beam Transverse profile Transverse emittance Absolute energy measurement (0.5% resolution) Longitudinal profile

Beam Diagnostic Box “Short” and “Long” type Collimators Scanning slit Stripping foils Faraday Cup Si. detector Collimators beam Si telescope Vacuum pump “Short” and “Long” type

HIE ISOLDE layout – Beam Instrumentation 5 “short” and 8 “long” diagnostic boxes are installed, next month 5 more “long” boxes will be installed All boxes have: Faraday Cup Scanning Slit Collimator blade Additional devices: Silicon Detectors (x4 + 1) Stripping Foils (x2) Silicon Telescope (x1 + 2) XLN2.BDB.0300 XT00.BDB.1300 XT00.BDB.1600 XT00.BDB.1900 XT00.BDB.2200 XT00.BDB.2500 XLN3.BDB.0300 XLN4.BDB.0300 XLN5.BDB.0300 XT00.BDB.0700 XT00.BDB.1050 XT01.BDB.0900 XT02.BDB.1100 XT03.BDB.0900 XT02.BDB.0630 XT01.BDB.0400 XT02.BDB.0400 XT03.BDB.0400

Faraday Cups (direct charge collection): Short and long Faraday Cups schematic design

FC and Scanning slit (profile measurement)

FC and Scanning slit (profile measurement) The beam reading in the FC is altered when the beam is off-centered / too large and hits repeller

FC and 2 Scanning slits (transverse emittance)

Quadrupole and scanning slit (emittance) FC and Scanning Slits at XT00.BDB.1000 Scan current of XT00.RQ.0800 Measuring the transverse beam properties (emittance and Twiss parameters) using the Quadropole Scan method was evaluated by Niels Bidault (BE-OP-ISO) This method will be used with weak beams using a Si detector as a low beam current measurement device that is necessary for HELIOS experiment Will be compared and validated using the double-slit method k [m-2] <x>2rms [m2] Results of one of the Quad Scans 𝑥 𝑟𝑚𝑠 2 measured for different quadrupole focusing strengths 𝑘 and fit to a parabola < 𝑥 𝑟𝑚𝑠 2 > =𝑎 𝑘 2 −2𝑎𝑏𝑘+𝑎 𝑏 2 +𝑐. The transverse properties of the beam can be derived from: 𝜎 0 = 𝛽𝜀 −𝛼𝜀 −𝛼𝜀 𝛾𝜀 = 𝑎 𝑑 2 𝑙 2 𝑎 𝑑 2 𝑙 2 (𝑏𝑙− 1 𝑑 ) 𝑎 𝑑 2 𝑙 2 (𝑏𝑙− 1 𝑑 ) 𝑐 𝑑 2 + 𝑎 𝑑 2 𝑙 2 (𝑏𝑙− 1 𝑑 ) 2 where 𝜀= 𝜎 = 𝑎𝑐 𝑑 2 𝑙 2 is the beam emittance, 𝑑 the drift length and 𝑙 the quadrupole length

Silicon Detectors 4 silicon detectors are installed Relative energy measurement for phasing cavities Absolute energy measurement Longitudinal profile 1 silicon detector will be installed in 2017 for emittance measurement of RIB using double slit or quadrupole scan techniques XLN2.BDB.0300 XT00.BDB.1300 XT00.BDB.1900 XT00.BDB.1050 XT01.BDB.0400

Cavity phasing

Cavity phasing using TOF information Change in energy when the phase of a SRF cavity is changed Phase [deg] dE [bin] -150 -100 -50 50 100 150 3800 3700 3600 3500 3400 3300 Change in TOF when the phase of a SRF cavity is changed Phase [deg] dTOF [ns] -150 -100 -50 50 100 150 25 20 15 10 5 This method is faster than using the information on the energy since beam currents can be higher (i.e. less saturation constrains) and all the events can be used to build up the statistics in multi-ion beams

Relative energy measurements using dipole B [T] I / IMAX Dipole scans for beams with different energies 1 mm vertical slits All quads and steerers off Silicon detector Energy measurements using the first dipole magnet of the XT01 line: Vertical slits (1 mm) were inserted before and after the dipole to select ions in the beam axis Quads and steerers were turned off The silicon detector in XT01.0400 was used to measure the beam rates for different settings of the dipole

Energy Measurements Using TOF XT00.1000 Si detector 7.76 m XT00.1900 Si detector time [ns] N / NMAX Bunch time structure for beams with different energies measured at XT00.1000 Si detector time [ns] N / NMAX Bunch time structure for beams with different energies measured at XT00.1900 Si detector The TOF system uses the time information provided by two silicon detectors separated 7.76 m from each other Energy changes smaller than 0.5 % could be easily resolved Bunch structure in second Si detector has partially degraded

Energy measurement: Pulse Height Defect Cocktail of beams (EBIS and Xe from GPS target) sent to the XT00.1000 silicon detector PHD is visible for heavy ions – time of flight technique should be used for energy measurement # Counts Energy bin # Energy spectrum for a beam with A/q = 4.0 and REX energy 132Xe33+ 40Ar10+ 20Ne5+ 16O4+ 4He1+ 12C3+ XT00.1000 deviation from linearity Mass Number (A) Ebin# / A Mass Number (A) Ebin# / A Deviation from linearity as a function of mass number XT00.1900 deviation from linearity Mass Number (A) Ebin# / A

Energy measurement: summary 3 different techniques were used for beam energy measurement (energy output of SD, dipole scan and time-of-flight measurements) After cross-calibration all methods give consistent results Changes of energy less than 0.5% could be resolved

FESA and SW HW layer FESA layer VME board HREXDBOB HREXDBOX_BI Control movement of devices Faraday Cup acquisition FC HV control Beam profile scan New release at the end of 2016y HREXDBOB HREXDBOX_BI HREXDBOX_FC HREXDBOX_SL Digitizer CAEN V1724 Energy measurement using Silicon Detector HREXDIGI TDC Acqiris TC890 Energy measurement using Time Of Flight technique using Silicon Detector HREXTOF Devices in BDB: Scanning slit Faraday cup Collimator slit Stripping foil Silicon detector ISEG HV power supply High Voltage control for Silicon Detector BHVVDS24

FESA For all classes expert applications are available HREXDBOB Full control of the custom made VME card: Stepping motors control Acquisition of the FC Control of custom made preamplifier for FC HV control of the FC Interlocks in VME to avoid collision of instruments Interlock system on FESA level to avoid collision of instruments Expert application HREXDBOX_BI, HREXDBOX_FC, HREXDBOX_SL Functionality and interface necessary for the specific type of the instrument HREXDIGI Control of CAEN V1724 digitizer Energy measurement Protection of the SD from damage by intense beam HREXTOF Time-of-flight measurements using AGILENT time to digital converter FESA class was developed during end of 2016-2017 based on requests from OP and is ready for use on stage2 BHVVDS24 Control of ISEG HV power supply used for SD FESA classes have been updated (new cards) and refactored (performance, interface) taking into account requests from OP during stage1 For all classes expert applications are available

Summary A completely new set of beam diagnostic devices has been developed, fabricated and installed in the superconducting linac and beam transfer lines. Software control system was deweloped for all diagnostic devices (FESA and expert tools). All the systems have been successfully commissioned and met specifications. Beam diagnostics will be complete (new diagnostic boxes and additional devices) and fully operational for this year run.

Acknowledgements This presentation includes work and contribution from many CERN colleagues, in particular William Andreazza, Stephane Bart Pedersen, Enrico Bravin, Stephane Burger, Esteban Cantero, Michel Duraffourg, Martino Ferrari, Gerrit Jan Focker, Alberto Rodriguez, Jean Tassan-Viol.